首页 > 代码库 > 开发经验集锦。
开发经验集锦。
原帖：http://www.jianshu.com/p/1ff9e44ccc78
作者：杂雾无尘
总结了几个月的东西终于能和大家分享了，不多说，直接看东西！
1、禁止手机睡眠
[UIApplication sharedApplication].idleTimerDisabled = YES;
2、隐藏某行cell
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
// 如果是你需要隐藏的那一行，返回高度为0
if(indexPath.row == YouWantToHideRow)
return 0;
return 44;
}
// 然后再你需要隐藏cell的时候调用
[self.tableView beginUpdates];
[self.tableView endUpdates];
3、禁用button高亮
button.adjustsImageWhenHighlighted = NO; 或者在创建的时候 UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
4、tableview遇到这种报错failed to obtain a cell from its dataSource
是因为你的cell被调用的早了。先循环使用了cell，后又创建cell。顺序错了
可能原因：1、xib的cell没有注册 2、内存中已经有这个cell的缓存了(也就是说通过你的cellId找到的cell并不是你想要的类型)，这时候需要改下cell的标识
5、cocoa pods报这个错误：unable to access ‘https://github.com/facebook/pop.git/‘: Operation timed out after 0 milliseconds with 0 out of 0 bytes received
解决办法：原因可能是网络问题，网络请求超时了，只需要重试就行了
6、cocoa pods 出现ERROR: While executing gem ... (Errno::EPERM)
解决办法：
https://segmentfault.com/q/1010000002926243
7、动画切换window的根控制器
// options是动画选项
[UIView transitionWithView:[UIApplication sharedApplication].keyWindow duration:0.5f options:UIViewAnimationOptionTransitionCrossDissolve animations:^{
BOOL oldState = [UIView areAnimationsEnabled];
[UIView setAnimationsEnabled:NO];
[UIApplication sharedApplication].keyWindow.rootViewController = [RootViewController new];
[UIView setAnimationsEnabled:oldState];
} completion:^(BOOL finished) {
}];
8、去除数组中重复的对象
NSArray *newArr = [oldArr valueForKeyPath:@“@distinctUnionOfObjects.self"];
9、编译的时候遇到 no such file or directory: ／users／apple／XXX
是因为编译的时候，在此路径下找不到这个文件，解决这个问题，首先是是要检查缺少的文件是不是在工程中，如果不在工程中，需要从本地拖进去，如果发现已经存在工程中了，或者拖进去还是报错，这时候需要去build phases中搜索这个文件，这时候很可能会搜出现两个相同的文件，这时候，有一个路径是正确的，删除另外一个即可。如果删除了还是不行，需要把两个都删掉，然后重新往工程里拖进这个文件即可
10、iOS8系统中，tableView最好实现下-tableView: heightForRowAtIndexPath:这个代理方法，要不然在iOS8中可能就会出现显示不全或者无法响应事件的问题
11、iOS8中实现侧滑功能的时候这个方法必须实现，要不然在iOS8中无法侧滑
// 必须写的方法，和editActionsForRowAtIndexPath配对使用，里面什么不写也行
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath {
}
12、三个通知
NSSystemTimeZoneDidChangeNotification监听修改时间界面的两个按钮状态变化
UIApplicationSignificantTimeChangeNotification 监听用户改变时间 （只要点击自动设置按钮就会调用） NSSystemClockDidChangeNotification 监听用户修改时间（时间不同才会调用）
13、SDWebImage本地缓存有时候会害人。如果之前缓存过一张图片，即使下次服务器换了这张图片，但是图片url没换，用sdwebimage下载下来的还是以前那张,所以遇到这种问题，不要先去怼服务器，清空下缓存再试就好了。
14、上线前注意：
-
1）、删掉代码中所有的测试代码
-
2）、如果后台有审核模式，提醒后台开启此模式
-
3）、主流程再跑一跑
-
4）、全局搜索waring，检查所有标记waring的地方
15、跳进app权限设置
// 跳进app设置
if (UIApplicationOpenSettingsURLString != NULL) {
NSURL *url = [NSURL URLWithString:UIApplicationOpenSettingsURLString];
[[UIApplication sharedApplication] openURL:url];
}
}
16、给一个view截图
UIGraphicsBeginImageContextWithOptions(view.bounds.size, YES, 0.0); [view.layer renderInContext:UIGraphicsGetCurrentContext()]; UIImage *img = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext();
17、开发中如果要动态修改tableView的tableHeaderView或者tableFooterView的高度，需要给tableView重新设置，而不是直接更改高度。正确的做法是重新设置一下tableView.tableFooterView = 更改过高度的view。为什么？其实在iOS8以上直接改高度是没有问题的，在iOS8中出现了contentSize不准确的问题，这是解决办法。
18、注意对象为nil的时候，调用此对象分类的方法不会执行
19、collectionView的内容小于其宽高的时候是不能滚动的，设置可以滚动：
collectionView.alwaysBounceHorizontal = YES; collectionView.alwaysBounceVertical = YES;
20、设置navigationBar上的title颜色和大小
[self.navigationController.navigationBar setTitleTextAttributes:@{NSForegroundColorAttributeName : [UIColor youColor], NSFontAttributeName : [UIFont systemFontOfSize:15]}]
21、颜色转图片
+ (UIImage *)cl_imageWithColor:(UIColor *)color {
CGRect rect = CGRectMake(0.0f, 0.0f, 1.0f, 1.0f);
UIGraphicsBeginImageContext(rect.size);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetFillColorWithColor(context, [color CGColor]);
CGContextFillRect(context, rect);
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}
22、view设置圆角
#define ViewBorderRadius(View, Radius, Width, Color)[View.layer setCornerRadius:(Radius)];[View.layer setMasksToBounds:YES];[View.layer setBorderWidth:(Width)];[View.layer setBorderColor:[Color CGColor]] // view圆角
23、强／弱引用
#define WeakSelf(type) __weak typeof(type) weak##type = type; // weak #define StrongSelf(type) __strong typeof(type) type = weak##type; // strong
24、由角度转换弧度
#define DegreesToRadian(x) (M_PI * (x) / 180.0)
25、由弧度转换角度
#define RadianToDegrees(radian) (radian*180.0)/(M_PI)
26、获取图片资源
#define GetImage(imageName) [UIImage imageNamed:[NSString stringWithFormat:@"%@",imageName]]
27、获取temp
#define PathTemp NSTemporaryDirectory()
28、获取沙盒 Document
#define PathDocument [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) firstObject]
29、获取沙盒 Cache
#define PathCache [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) firstObject]
30、GCD代码只执行一次
#define kDISPATCH_ONCE_BLOCK(onceBlock) static dispatch_once_t onceToken; dispatch_once(&onceToken, onceBlock);
31、自定义NSLog
#ifdef DEBUG #define NSLog(fmt, ...) NSLog((@"%s [Line %d] " fmt), __PRETTY_FUNCTION__, __LINE__, ##__VA_ARGS__) #else #define NSLog(...) #endif
32、Font
#define FontL(s) [UIFont systemFontOfSize:s weight:UIFontWeightLight] #define FontR(s) [UIFont systemFontOfSize:s weight:UIFontWeightRegular] #define FontB(s) [UIFont systemFontOfSize:s weight:UIFontWeightBold] #define FontT(s) [UIFont systemFontOfSize:s weight:UIFontWeightThin] #define Font(s) FontL(s)
33、FORMAT
#define FORMAT(f, ...) [NSString stringWithFormat:f, ## __VA_ARGS__]
34、在主线程上运行
#define kDISPATCH_MAIN_THREAD(mainQueueBlock) dispatch_async(dispatch_get_main_queue(), mainQueueBlock);
35、开启异步线程
#define kDISPATCH_GLOBAL_QUEUE_DEFAULT(globalQueueBlock) dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), globalQueueBlocl);
36、通知
#define NOTIF_ADD(n, f) [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(f) name:n object:nil] #define NOTIF_POST(n, o) [[NSNotificationCenter defaultCenter] postNotificationName:n object:o] #define NOTIF_REMV() [[NSNotificationCenter defaultCenter] removeObserver:self]
37、随机颜色
+ (UIColor *)RandomColor {
NSInteger aRedValue = arc4random() % 255;
NSInteger aGreenValue = arc4random() % 255;
NSInteger aBlueValue = arc4random() % 255;
UIColor *randColor = [UIColor colorWithRed:aRedValue / 255.0f green:aGreenValue / 255.0f blue:aBlueValue / 255.0f alpha:1.0f];
return randColor;
}
38、获取window
+(UIWindow*)getWindow {
UIWindow* win = nil; //[UIApplication sharedApplication].keyWindow;
for (id item in [UIApplication sharedApplication].windows) {
if ([item class] == [UIWindow class]) {
if (!((UIWindow*)item).hidden) {
win = item;
break;
}
}
}
return win;
}
39、修改textField的placeholder的字体颜色、大小
[textField setValue:[UIColor redColor] forKeyPath:@"_placeholderLabel.textColor"]; [textField setValue:[UIFont boldSystemFontOfSize:16] forKeyPath:@"_placeholderLabel.font"];
40、统一收起键盘
[[[UIApplication sharedApplication] keyWindow] endEditing:YES];
41、控制屏幕旋转，在控制器中写
/** 是否支持自动转屏 */
- (BOOL)shouldAutorotate {
return YES;
}
/** 支持哪些屏幕方向 */
- (UIInterfaceOrientationMask)supportedInterfaceOrientations {
return UIInterfaceOrientationMaskLandscapeLeft | UIInterfaceOrientationMaskLandscapeRight;
}
/** 默认的屏幕方向（当前ViewController必须是通过模态出来的UIViewController（模态带导航的无效）方式展现出来的，才会调用这个方法） */
- (UIInterfaceOrientation)preferredInterfaceOrientationForPresentation {
return UIInterfaceOrientationLandscapeLeft | UIInterfaceOrientationLandscapeRight;
}
42、获取app缓存大小
- (CGFloat)getCachSize {
NSUInteger imageCacheSize = [[SDImageCache sharedImageCache] getSize];
//获取自定义缓存大小
//用枚举器遍历 一个文件夹的内容
//1.获取 文件夹枚举器
NSString *myCachePath = [NSHomeDirectory() stringByAppendingPathComponent:@"Library/Caches"];
NSDirectoryEnumerator *enumerator = [[NSFileManager defaultManager] enumeratorAtPath:myCachePath];
__block NSUInteger count = 0;
//2.遍历
for (NSString *fileName in enumerator) {
NSString *path = [myCachePath stringByAppendingPathComponent:fileName];
NSDictionary *fileDict = [[NSFileManager defaultManager] attributesOfItemAtPath:path error:nil];
count += fileDict.fileSize;//自定义所有缓存大小
}
// 得到是字节 转化为M
CGFloat totalSize = ((CGFloat)imageCacheSize+count)/1024/1024;
return totalSize;
}
43、清理app缓存
- (void)handleClearView {
//删除两部分
//1.删除 sd 图片缓存
//先清除内存中的图片缓存
[[SDImageCache sharedImageCache] clearMemory];
//清除磁盘的缓存
[[SDImageCache sharedImageCache] clearDisk];
//2.删除自己缓存
NSString *myCachePath = [NSHomeDirectory() stringByAppendingPathComponent:@"Library/Caches"];
[[NSFileManager defaultManager] removeItemAtPath:myCachePath error:nil];
}
44、模型转字典
static NSSet *classes;
- (NSMutableDictionary *)getParameterDictionary {
NSMutableDictionary *dict = [NSMutableDictionary dictionary];
Class c = self.class;
while (c) {
unsigned count;
objc_property_t *properties = class_copyPropertyList([c class], &count);
for (int i = 0; i < count; i++) {
NSString *key = [NSString stringWithUTF8String:property_getName(properties[i])];
dict[key] = [self valueForKey:key];
}
free(properties);
// 获得父类
c = class_getSuperclass(c);
if ([self isClassFromFoundation:c]) break;
}
return dict;
}
- (BOOL)isClassFromFoundation:(Class)c
{
if (c == [NSObject class] || c == [NSManagedObject class]) return YES;
__block BOOL result = NO;
[[self foundationClasses] enumerateObjectsUsingBlock:^(Class foundationClass, BOOL *stop) {
if ([c isSubclassOfClass:foundationClass]) {
result = YES;
*stop = YES;
}
}];
return result;
}
- (NSSet *)foundationClasses
{
if (classes == nil) {
// 集合中没有NSObject，因为几乎所有的类都是继承自NSObject，具体是不是NSObject需要特殊判断
classes = [NSSet setWithObjects:
[NSURL class],
[NSDate class],
[NSValue class],
[NSData class],
[NSError class],
[NSArray class],
[NSDictionary class],
[NSString class],
[NSAttributedString class], nil];
}
return classes;
}
45、交换两个方法实现
Class aClass = [self class];
SEL originalSelector = @selector(viewWillAppear:);
SEL swizzledSelector = @selector(xxx_viewWillAppear:);
Method originalMethod = class_getInstanceMethod(aClass, originalSelector);
Method swizzledMethod = class_getInstanceMethod(aClass, swizzledSelector);
BOOL didAddMethod =
class_addMethod(aClass,
originalSelector,
method_getImplementation(swizzledMethod),
method_getTypeEncoding(swizzledMethod));
if (didAddMethod) {
class_replaceMethod(aClass,
swizzledSelector,
method_getImplementation(originalMethod),
method_getTypeEncoding(originalMethod));
} else {
method_exchangeImplementations(originalMethod, swizzledMethod);
}
46、打印百分号和引号
NSLog(@"%%"); NSLog(@"\"");
47、几个常用权限判断
if ([CLLocationManager authorizationStatus] ==kCLAuthorizationStatusDenied) {
NSLog(@"没有定位权限");
}
AVAuthorizationStatus statusVideo = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeVideo];
if (statusVideo == AVAuthorizationStatusDenied) {
NSLog(@"没有摄像头权限");
}
//是否有麦克风权限
AVAuthorizationStatus statusAudio = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeAudio];
if (statusAudio == AVAuthorizationStatusDenied) {
NSLog(@"没有录音权限");
}
[PHPhotoLibrary requestAuthorization:^(PHAuthorizationStatus status) {
if (status == PHAuthorizationStatusDenied) {
NSLog(@"没有相册权限");
}
}];
48、获取手机型号
+ (NSString *)getDeviceInfo {
struct utsname systemInfo;
uname(&systemInfo);
NSString *platform = [NSString stringWithCString:systemInfo.machine encoding:NSASCIIStringEncoding];
if ([platform isEqualToString:@"iPhone1,1"]) return @"iPhone 2G";
if ([platform isEqualToString:@"iPhone1,2"]) return @"iPhone 3G";
if ([platform isEqualToString:@"iPhone2,1"]) return @"iPhone 3GS";
if ([platform isEqualToString:@"iPhone3,1"]) return @"iPhone 4";
if ([platform isEqualToString:@"iPhone3,2"]) return @"iPhone 4";
if ([platform isEqualToString:@"iPhone3,3"]) return @"iPhone 4";
if ([platform isEqualToString:@"iPhone4,1"]) return @"iPhone 4S";
if ([platform isEqualToString:@"iPhone5,1"]) return @"iPhone 5";
if ([platform isEqualToString:@"iPhone5,2"]) return @"iPhone 5";
if ([platform isEqualToString:@"iPhone5,3"]) return @"iPhone 5c";
if ([platform isEqualToString:@"iPhone5,4"]) return @"iPhone 5c";
if ([platform isEqualToString:@"iPhone6,1"]) return @"iPhone 5s";
if ([platform isEqualToString:@"iPhone6,2"]) return @"iPhone 5s";
if ([platform isEqualToString:@"iPhone7,1"]) return @"iPhone 6 Plus";
if ([platform isEqualToString:@"iPhone7,2"]) return @"iPhone 6";
if ([platform isEqualToString:@"iPhone8,1"]) return @"iPhone 6s";
if ([platform isEqualToString:@"iPhone8,2"]) return @"iPhone 6s Plus";
// 日行两款手机型号均为日本独占，可能使用索尼FeliCa支付方案而不是苹果支付
if ([platform isEqualToString:@"iPhone9,1"]) return @"国行、日版、港行iPhone 7";
if ([platform isEqualToString:@"iPhone9,2"]) return @"港行、国行iPhone 7 Plus";
if ([platform isEqualToString:@"iPhone9,3"]) return @"美版、台版iPhone 7";
if ([platform isEqualToString:@"iPhone9,4"]) return @"美版、台版iPhone 7 Plus";
if ([platform isEqualToString:@"iPhone8,4"]) return @"iPhone SE";
if ([platform isEqualToString:@"iPod1,1"]) return @"iPod Touch 1G";
if ([platform isEqualToString:@"iPod2,1"]) return @"iPod Touch 2G";
if ([platform isEqualToString:@"iPod3,1"]) return @"iPod Touch 3G";
if ([platform isEqualToString:@"iPod4,1"]) return @"iPod Touch 4G";
if ([platform isEqualToString:@"iPod5,1"]) return @"iPod Touch 5G";
if ([platform isEqualToString:@"iPad1,1"]) return @"iPad 1G";
if ([platform isEqualToString:@"iPad2,1"]) return @"iPad 2";
if ([platform isEqualToString:@"iPad2,2"]) return @"iPad 2";
if ([platform isEqualToString:@"iPad2,3"]) return @"iPad 2";
if ([platform isEqualToString:@"iPad2,4"]) return @"iPad 2";
if ([platform isEqualToString:@"iPad2,5"]) return @"iPad Mini 1G";
if ([platform isEqualToString:@"iPad2,6"]) return @"iPad Mini 1G";
if ([platform isEqualToString:@"iPad2,7"]) return @"iPad Mini 1G";
if ([platform isEqualToString:@"iPad3,1"]) return @"iPad 3";
if ([platform isEqualToString:@"iPad3,2"]) return @"iPad 3";
if ([platform isEqualToString:@"iPad3,3"]) return @"iPad 3";
if ([platform isEqualToString:@"iPad3,4"]) return @"iPad 4";
if ([platform isEqualToString:@"iPad3,5"]) return @"iPad 4";
if ([platform isEqualToString:@"iPad3,6"]) return @"iPad 4";
if ([platform isEqualToString:@"iPad4,1"]) return @"iPad Air";
if ([platform isEqualToString:@"iPad4,2"]) return @"iPad Air";
if ([platform isEqualToString:@"iPad4,3"]) return @"iPad Air";
if ([platform isEqualToString:@"iPad4,4"]) return @"iPad Mini 2G";
if ([platform isEqualToString:@"iPad4,5"]) return @"iPad Mini 2G";
if ([platform isEqualToString:@"iPad4,6"]) return @"iPad Mini 2G";
if ([platform isEqualToString:@"i386"]) return @"iPhone Simulator";
if ([platform isEqualToString:@"x86_64"]) return @"iPhone Simulator";
return platform;
}
49、长按复制功能
- (void)viewDidLoad
{
[self.view addGestureRecognizer:[[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(pasteBoard:)]];
}
- (void)pasteBoard:(UILongPressGestureRecognizer *)longPress {
if (longPress.state == UIGestureRecognizerStateBegan) {
UIPasteboard *pasteboard = [UIPasteboard generalPasteboard];
pasteboard.string = @"需要复制的文本";
}
}
50、cocoapods升级
在终端执行 sudo gem install -n / usr / local / bin cocoapods --pre
51、设置启动页后，依然显示之前的
删除app，手机重启，重新安装
52、判断图片类型
//通过图片Data数据第一个字节 来获取图片扩展名
- (NSString *)contentTypeForImageData:(NSData *)data
{
uint8_t c;
[data getBytes:&c length:1];
switch (c)
{
case 0xFF:
return @"jpeg";
case 0x89:
return @"png";
case 0x47:
return @"gif";
case 0x49:
case 0x4D:
return @"tiff";
case 0x52:
if ([data length] < 12) {
return nil;
}
NSString *testString = [[NSString alloc] initWithData:[data subdataWithRange:NSMakeRange(0, 12)] encoding:NSASCIIStringEncoding];
if ([testString hasPrefix:@"RIFF"]
&& [testString hasSuffix:@"WEBP"])
{
return @"webp";
}
return nil;
}
return nil;
}
53、获取手机和app信息
NSDictionary *infoDictionary = [[NSBundle mainBundle] infoDictionary]; CFShow(infoDictionary); // app名称 NSString *app_Name = [infoDictionary objectForKey:@"CFBundleDisplayName"]; // app版本 NSString *app_Version = [infoDictionary objectForKey:@"CFBundleShortVersionString"]; // app build版本 NSString *app_build = [infoDictionary objectForKey:@"CFBundleVersion"]; //手机序列号 NSString* identifierNumber = [[UIDevice currentDevice] uniqueIdentifier]; NSLog(@"手机序列号: %@",identifierNumber); //手机别名： 用户定义的名称 NSString* userPhoneName = [[UIDevice currentDevice] name]; NSLog(@"手机别名: %@", userPhoneName); //设备名称 NSString* deviceName = [[UIDevice currentDevice] systemName]; NSLog(@"设备名称: %@",deviceName ); //手机系统版本 NSString* phoneVersion = [[UIDevice currentDevice] systemVersion]; NSLog(@"手机系统版本: %@", phoneVersion); //手机型号 NSString* phoneModel = [[UIDevice currentDevice] model]; NSLog(@"手机型号: %@",phoneModel ); //地方型号 （国际化区域名称） NSString* localPhoneModel = [[UIDevice currentDevice] localizedModel]; NSLog(@"国际化区域名称: %@",localPhoneModel ); NSDictionary *infoDictionary = [[NSBundle mainBundle] infoDictionary]; // 当前应用名称 NSString *appCurName = [infoDictionary objectForKey:@"CFBundleDisplayName"]; NSLog(@"当前应用名称：%@",appCurName); // 当前应用软件版本 比如：1.0.1 NSString *appCurVersion = [infoDictionary objectForKey:@"CFBundleShortVersionString"]; NSLog(@"当前应用软件版本:%@",appCurVersion); // 当前应用版本号码 int类型 NSString *appCurVersionNum = [infoDictionary objectForKey:@"CFBundleVersion"]; NSLog(@"当前应用版本号码：%@",appCurVersionNum);
54、获取一个类的所有属性
id LenderClass = objc_getClass("Lender");
unsigned int outCount, i;
objc_property_t *properties = class_copyPropertyList(LenderClass, &outCount);
for (i = 0; i < outCount; i++) {
objc_property_t property = properties[i];
fprintf(stdout, "%s %s\n", property_getName(property), property_getAttributes(property));
}
55、image圆角
- (UIImage *)circleImage
{
// NO代表透明
UIGraphicsBeginImageContextWithOptions(self.size, NO, 1);
// 获得上下文
CGContextRef ctx = UIGraphicsGetCurrentContext();
// 添加一个圆
CGRect rect = CGRectMake(0, 0, self.size.width, self.size.height);
// 方形变圆形
CGContextAddEllipseInRect(ctx, rect);
// 裁剪
CGContextClip(ctx);
// 将图片画上去
[self drawInRect:rect];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}
56、image拉伸
+ (UIImage *)resizableImage:(NSString *)imageName
{
UIImage *image = [UIImage imageNamed:imageName];
CGFloat imageW = image.size.width;
CGFloat imageH = image.size.height;
return [image resizableImageWithCapInsets:UIEdgeInsetsMake(imageH * 0.5, imageW * 0.5, imageH * 0.5, imageW * 0.5) resizingMode:UIImageResizingModeStretch];
}
57、JSON字符串转字典
+ (NSDictionary *)parseJSONStringToNSDictionary:(NSString *)JSONString {
NSData *JSONData = [JSONString dataUsingEncoding:NSUTF8StringEncoding];
NSDictionary *responseJSON = [NSJSONSerialization JSONObjectWithData:JSONData options:NSJSONReadingMutableLeaves error:nil];
return responseJSON;
}
58、身份证号验证
- (BOOL)validateIdentityCard {
BOOL flag;
if (self.length <= 0) {
flag = NO;
return flag;
}
NSString *regex2 = @"^(\\d{14}|\\d{17})(\\d|[xX])$";
NSPredicate *identityCardPredicate = [NSPredicate predicateWithFormat:@"SELF MATCHES %@",regex2];
return [identityCardPredicate evaluateWithObject:self];
}
59、获取设备mac地址
+ (NSString *)macAddress {
int mib[6];
size_t len;
char *buf;
unsigned char *ptr;
struct if_msghdr *ifm;
struct sockaddr_dl *sdl;
mib[0] = CTL_NET;
mib[1] = AF_ROUTE;
mib[2] = 0;
mib[3] = AF_LINK;
mib[4] = NET_RT_IFLIST;
if((mib[5] = if_nametoindex("en0")) == 0) {
printf("Error: if_nametoindex error\n");
return NULL;
}
if(sysctl(mib, 6, NULL, &len, NULL, 0) < 0) {
printf("Error: sysctl, take 1\n");
return NULL;
}
if((buf = malloc(len)) == NULL) {
printf("Could not allocate memory. Rrror!\n");
return NULL;
}
if(sysctl(mib, 6, buf, &len, NULL, 0) < 0) {
printf("Error: sysctl, take 2");
return NULL;
}
ifm = (struct if_msghdr *)buf;
sdl = (struct sockaddr_dl *)(ifm + 1);
ptr = (unsigned char *)LLADDR(sdl);
NSString *outstring = [NSString stringWithFormat:@"X:X:X:X:X:X",
*ptr, *(ptr+1), *(ptr+2), *(ptr+3), *(ptr+4), *(ptr+5)];
free(buf);
return outstring;
}
60、导入自定义字体库
-
1、找到你想用的字体的 ttf 格式，拖入工程
-
2、在工程的plist中增加一行数组，“Fonts provided by application”
-
3、为这个key添加一个item，value为你刚才导入的ttf文件名
-
4、直接使用即可：label.font = [UIFont fontWithName:@"你刚才导入的ttf文件名" size:20.0]；
61、拿到当前正在显示的控制器，不管是push进去的，还是present进去的都能拿到
- (UIViewController *)getVisibleViewControllerFrom:(UIViewController*)vc {
if ([vc isKindOfClass:[UINavigationController class]]) {
return [self getVisibleViewControllerFrom:[((UINavigationController*) vc) visibleViewController]];
}else if ([vc isKindOfClass:[UITabBarController class]]){
return [self getVisibleViewControllerFrom:[((UITabBarController*) vc) selectedViewController]];
} else {
if (vc.presentedViewController) {
return [self getVisibleViewControllerFrom:vc.presentedViewController];
} else {
return vc;
}
}
}
62、runtime为一个类动态添加属性
// 动态添加属性的本质是: 让对象的某个属性与值产生关联 objc_setAssociatedObject(self, WZBPlaceholderViewKey, placeholderView, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
63、获取runtime为一个类动态添加的属性
objc_getAssociatedObject(self, WZBPlaceholderViewKey);
64、KVO监听某个对象的属性
// 添加监听者
[self addObserver:self forKeyPath:property options:NSKeyValueObservingOptionNew context:nil];
// 当监听的属性值变化的时候会来到这个方法
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context {
if ([keyPath isEqualToString:@"property"]) {
[self textViewTextChange];
} else {
}
}
65、Reachability判断网络状态
NetworkStatus status = [[Reachability reachabilityForInternetConnection] currentReachabilityStatus];
if (status == NotReachable) {
NSLog(@"当前设备无网络");
}
if (status == ReachableViaWiFi) {
NSLog(@"当前wifi网络");
}
if (status == NotReachable) {
NSLog(@"当前蜂窝移动网络");
}
66、AFNetworking监听网络状态
// 监听网络状况
AFNetworkReachabilityManager *mgr = [AFNetworkReachabilityManager sharedManager];
[mgr setReachabilityStatusChangeBlock:^(AFNetworkReachabilityStatus status) {
switch (status) {
case AFNetworkReachabilityStatusUnknown:
break;
case AFNetworkReachabilityStatusNotReachable: {
[SVProgressHUD showInfoWithStatus:@"当前设备无网络"];
}
break;
case AFNetworkReachabilityStatusReachableViaWiFi:
[SVProgressHUD showInfoWithStatus:@"当前Wi-Fi网络"];
break;
case AFNetworkReachabilityStatusReachableViaWWAN:
[SVProgressHUD showInfoWithStatus:@"当前蜂窝移动网络"];
break;
default:
break;
}
}];
[mgr startMonitoring];
67、透明颜色不影响子视图透明度
[UIColor colorWithRed: green: blue: alpha:];
68、取图片某一点的颜色
if (point.x < 0 || point.y < 0) return nil;
CGImageRef imageRef = self.CGImage;
NSUInteger width = CGImageGetWidth(imageRef);
NSUInteger height = CGImageGetHeight(imageRef);
if (point.x >= width || point.y >= height) return nil;
unsigned char *rawData = malloc(height * width * 4);
if (!rawData) return nil;
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
NSUInteger bytesPerPixel = 4;
NSUInteger bytesPerRow = bytesPerPixel * width;
NSUInteger bitsPerComponent = 8;
CGContextRef context = CGBitmapContextCreate(rawData,
width,
height,
bitsPerComponent,
bytesPerRow,
colorSpace,
kCGImageAlphaPremultipliedLast
| kCGBitmapByteOrder32Big);
if (!context) {
free(rawData);
return nil;
}
CGColorSpaceRelease(colorSpace);
CGContextDrawImage(context, CGRectMake(0, 0, width, height), imageRef);
CGContextRelease(context);
int byteIndex = (bytesPerRow * point.y) + point.x * bytesPerPixel;
CGFloat red = (rawData[byteIndex] * 1.0) / 255.0;
CGFloat green = (rawData[byteIndex + 1] * 1.0) / 255.0;
CGFloat blue = (rawData[byteIndex + 2] * 1.0) / 255.0;
CGFloat alpha = (rawData[byteIndex + 3] * 1.0) / 255.0;
UIColor *result = nil;
result = [UIColor colorWithRed:red green:green blue:blue alpha:alpha];
free(rawData);
return result;
69、判断该图片是否有透明度通道
- (BOOL)hasAlphaChannel
{
CGImageAlphaInfo alpha = CGImageGetAlphaInfo(self.CGImage);
return (alpha == kCGImageAlphaFirst ||
alpha == kCGImageAlphaLast ||
alpha == kCGImageAlphaPremultipliedFirst ||
alpha == kCGImageAlphaPremultipliedLast);
}
70、获得灰度图
+ (UIImage*)covertToGrayImageFromImage:(UIImage*)sourceImage
{
int width = sourceImage.size.width;
int height = sourceImage.size.height;
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceGray();
CGContextRef context = CGBitmapContextCreate (nil,width,height,8,0,colorSpace,kCGImageAlphaNone);
CGColorSpaceRelease(colorSpace);
if (context == NULL) {
return nil;
}
CGContextDrawImage(context,CGRectMake(0, 0, width, height), sourceImage.CGImage);
CGImageRef contextRef = CGBitmapContextCreateImage(context);
UIImage *grayImage = [UIImage imageWithCGImage:contextRef];
CGContextRelease(context);
CGImageRelease(contextRef);
return grayImage;
}
71、根据bundle中的文件名读取图片
+ (UIImage *)imageWithFileName:(NSString *)name {
NSString *extension = @"png";
NSArray *components = [name componentsSeparatedByString:@"."];
if ([components count] >= 2) {
NSUInteger lastIndex = components.count - 1;
extension = [components objectAtIndex:lastIndex];
name = [name substringToIndex:(name.length-(extension.length+1))];
}
// 如果为Retina屏幕且存在对应图片，则返回Retina图片，否则查找普通图片
if ([UIScreen mainScreen].scale == 2.0) {
name = [name stringByAppendingString:@"@2x"];
NSString *path = [[NSBundle mainBundle] pathForResource:name ofType:extension];
if (path != nil) {
return [UIImage imageWithContentsOfFile:path];
}
}
if ([UIScreen mainScreen].scale == 3.0) {
name = [name stringByAppendingString:@"@3x"];
NSString *path = [[NSBundle mainBundle] pathForResource:name ofType:extension];
if (path != nil) {
return [UIImage imageWithContentsOfFile:path];
}
}
NSString *path = [[NSBundle mainBundle] pathForResource:name ofType:extension];
if (path) {
return [UIImage imageWithContentsOfFile:path];
}
return nil;
}
72、合并两个图片
+ (UIImage*)mergeImage:(UIImage*)firstImage withImage:(UIImage*)secondImage {
CGImageRef firstImageRef = firstImage.CGImage;
CGFloat firstWidth = CGImageGetWidth(firstImageRef);
CGFloat firstHeight = CGImageGetHeight(firstImageRef);
CGImageRef secondImageRef = secondImage.CGImage;
CGFloat secondWidth = CGImageGetWidth(secondImageRef);
CGFloat secondHeight = CGImageGetHeight(secondImageRef);
CGSize mergedSize = CGSizeMake(MAX(firstWidth, secondWidth), MAX(firstHeight, secondHeight));
UIGraphicsBeginImageContext(mergedSize);
[firstImage drawInRect:CGRectMake(0, 0, firstWidth, firstHeight)];
[secondImage drawInRect:CGRectMake(0, 0, secondWidth, secondHeight)];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}
73、根据bundle中的图片名创建imageview
+ (id)imageViewWithImageNamed:(NSString*)imageName
{
return [[UIImageView alloc] initWithImage:[UIImage imageNamed:imageName]];
}
74、为imageView添加倒影
CGRect frame = self.frame; frame.origin.y += (frame.size.height + 1); UIImageView *reflectionImageView = [[UIImageView alloc] initWithFrame:frame]; self.clipsToBounds = TRUE; reflectionImageView.contentMode = self.contentMode; [reflectionImageView setImage:self.image]; reflectionImageView.transform = CGAffineTransformMakeScale(1.0, -1.0); CALayer *reflectionLayer = [reflectionImageView layer]; CAGradientLayer *gradientLayer = [CAGradientLayer layer]; gradientLayer.bounds = reflectionLayer.bounds; gradientLayer.position = CGPointMake(reflectionLayer.bounds.size.width / 2, reflectionLayer.bounds.size.height * 0.5); gradientLayer.colors = [NSArray arrayWithObjects: (id)[[UIColor clearColor] CGColor], (id)[[UIColor colorWithRed:1.0 green:1.0 blue:1.0 alpha:0.3] CGColor], nil]; gradientLayer.startPoint = CGPointMake(0.5,0.5); gradientLayer.endPoint = CGPointMake(0.5,1.0); reflectionLayer.mask = gradientLayer; [self.superview addSubview:reflectionImageView];
75、画水印
// 画水印
- (void) setImage:(UIImage *)image withWaterMark:(UIImage *)mark inRect:(CGRect)rect
{
if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 4.0)
{
UIGraphicsBeginImageContextWithOptions(self.frame.size, NO, 0.0);
}
//原图
[image drawInRect:self.bounds];
//水印图
[mark drawInRect:rect];
UIImage *newPic = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
self.image = newPic;
}
76、让label的文字内容显示在左上／右上／左下／右下／中心顶／中心底部
自定义UILabel
// 重写label的textRectForBounds方法
- (CGRect)textRectForBounds:(CGRect)bounds limitedToNumberOfLines:(NSInteger)numberOfLines {
CGRect rect = [super textRectForBounds:bounds limitedToNumberOfLines:numberOfLines];
switch (self.textAlignmentType) {
case WZBTextAlignmentTypeLeftTop: {
rect.origin = bounds.origin;
}
break;
case WZBTextAlignmentTypeRightTop: {
rect.origin = CGPointMake(CGRectGetMaxX(bounds) - rect.size.width, bounds.origin.y);
}
break;
case WZBTextAlignmentTypeLeftBottom: {
rect.origin = CGPointMake(bounds.origin.x, CGRectGetMaxY(bounds) - rect.size.height);
}
break;
case WZBTextAlignmentTypeRightBottom: {
rect.origin = CGPointMake(CGRectGetMaxX(bounds) - rect.size.width, CGRectGetMaxY(bounds) - rect.size.height);
}
break;
case WZBTextAlignmentTypeTopCenter: {
rect.origin = CGPointMake((CGRectGetWidth(bounds) - CGRectGetWidth(rect)) / 2, CGRectGetMaxY(bounds) - rect.origin.y);
}
break;
case WZBTextAlignmentTypeBottomCenter: {
rect.origin = CGPointMake((CGRectGetWidth(bounds) - CGRectGetWidth(rect)) / 2, CGRectGetMaxY(bounds) - CGRectGetMaxY(bounds) - rect.size.height);
}
break;
case WZBTextAlignmentTypeLeft: {
rect.origin = CGPointMake(0, rect.origin.y);
}
break;
case WZBTextAlignmentTypeRight: {
rect.origin = CGPointMake(rect.origin.x, 0);
}
break;
case WZBTextAlignmentTypeCenter: {
rect.origin = CGPointMake((CGRectGetWidth(bounds) - CGRectGetWidth(rect)) / 2, (CGRectGetHeight(bounds) - CGRectGetHeight(rect)) / 2);
}
break;
default:
break;
}
return rect;
}
- (void)drawTextInRect:(CGRect)rect {
CGRect textRect = [self textRectForBounds:rect limitedToNumberOfLines:self.numberOfLines];
[super drawTextInRect:textRect];
}
77、scrollView上的输入框，键盘挡住的问题
推荐用IQKeyboardManager这个框架！
手动解决如下
1、监听键盘弹出／消失的通知
2、在通知中加入代码：
NSDictionary* info = [aNotification userInfo];
CGRect keyPadFrame=[[UIApplication sharedApplication].keyWindow convertRect:[[info objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue] fromView:self.view];
CGSize kbSize =keyPadFrame.size;
CGRect activeRect=[self.view convertRect:activeField.frame fromView:activeField.superview];
CGRect aRect = self.view.bounds;
aRect.size.height -= (kbSize.height);
CGPoint origin = activeRect.origin;
origin.y -= backScrollView.contentOffset.y;
if (!CGRectContainsPoint(aRect, origin)) {
CGPoint scrollPoint = CGPointMake(0.0,CGRectGetMaxY(activeRect)-(aRect.size.height));
[backScrollView setContentOffset:scrollPoint animated:YES];
}
78、frame布局的cell动态高度
这种通常在你的模型中添加一个辅助属性cellHeight，在模型中重写这个属性的get方法，根据你的布局和模型中的其他属性值计算出总高度。最后在tableView：heightForRow方法中，根据indexPath找出对应的模型，返回这个高度即可。
79、AutoLayout布局的cell动态高度
// 1、设置tableView的属性 self.tableView.rowHeight = UITableViewAutomaticDimension; self.tableView.estimatedRowHeight = 44.0; // 这个属性非0，估计cell高度 // 2、至上而下设置cell的约束，注意，上下左右最好都要顶到cell的四周
cell
80、使用performSelector:调用函数，内存泄漏问题
当我们在开发中使用[obj performSelector:NSSelectorFromString(@"aMethod")];这类方法时可能会收到一个警告"performSelector may cause a leak because its selector is unknown".
是因为编译器不清楚这个对象能不能相应这个方法，如果不能，则是不安全的，而且编译器也不清楚该怎么处理这个方法的返回值！
使用以下代码调用即可：
if (! obj) { return; }
SEL selector = NSSelectorFromString(@"aMethod");
IMP imp = [obj methodForSelector:selector];
void (*func)(id, SEL) = (void *)imp;
func(obj, selector);
或者：
SEL selector = NSSelectorFromString(@"aMethod");
((void (*)(id, SEL))[obj methodForSelector:selector])(obj, selector);
81、一个字符串是否包含另一个字符串
// 方法1
if ([str1 containsString:str2]) {
NSLog(@"str1包含str2");
} else {
NSLog(@"str1不包含str2");
}
// 方法2
if ([str1 rangeOfString: str2].location == NSNotFound) {
NSLog(@"str1包含str2");
} else {
NSLog(@"str1不包含str2");
}
82、cell去除选中效果
cell.selectionStyle = UITableViewCellSelectionStyleNone;
83、cell点按效果
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
[tableView deselectRowAtIndexPath:indexPath animated:YES];
}
84、当删除一个从xib拖出来的属性时，一定记得把xib中对应的线也删掉，不然会报类似[setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key的crash
点击这个叉号删除
85、真机测试的时候报错：Could not launch "你的 App"，process launch failed: Security
因为你的app没有上线，iOS9开始，需要手动信任Xcode生成的描述文件，打开手机设置->通用->描述文件->点击你的app的描述文件->点击信任
86、真机测试的时候报错：Could not find Developer Disk Image
这是因为你的设备系统版本大于Xcode能兼容的系统版本，比如你的设备是iOS10.3，而Xcode版本是8.2（Xcode8.2最大兼容iOS10.2），就会报这个错误。解决办法就是升级Xcode！
87、UITextView没有placeholder的问题？
网上有很多此类自定义控件，也可以参考下我写的一个UITextView分类 UITextView-WZB
88、移除字符串中的空格和换行
+ (NSString *)removeSpaceAndNewline:(NSString *)str {
NSString *temp = [str stringByReplacingOccurrencesOfString:@" " withString:@""];
temp = [temp stringByReplacingOccurrencesOfString:@"\r" withString:@""];
temp = [temp stringByReplacingOccurrencesOfString:@"\n" withString:@""];
return temp;
}
89、判断字符串中是否有空格
+ (BOOL)isBlank:(NSString *)str {
NSRange _range = [str rangeOfString:@" "];
if (_range.location != NSNotFound) {
//有空格
return YES;
} else {
//没有空格
return NO;
}
}
90、获取一个视频的第一帧图片
NSURL *url = [NSURL URLWithString:filepath]; AVURLAsset *asset1 = [[AVURLAsset alloc] initWithURL:url options:nil]; AVAssetImageGenerator *generate1 = [[AVAssetImageGenerator alloc] initWithAsset:asset1]; generate1.appliesPreferredTrackTransform = YES; NSError *err = NULL; CMTime time = CMTimeMake(1, 2); CGImageRef oneRef = [generate1 copyCGImageAtTime:time actualTime:NULL error:&err]; UIImage *one = [[UIImage alloc] initWithCGImage:oneRef]; return one;
91、获取视频的时长
+ (NSInteger)getVideoTimeByUrlString:(NSString *)urlString {
NSURL *videoUrl = [NSURL URLWithString:urlString];
AVURLAsset *avUrl = [AVURLAsset assetWithURL:videoUrl];
CMTime time = [avUrl duration];
int seconds = ceil(time.value/time.timescale);
return seconds;
}
92、字符串是否为空
+ (BOOL)isEqualToNil:(NSString *)str {
return str.length <= 0 || [str isEqualToString:@""] || !str;
}
93、将app上传到App Store的时候通常会遇到这个问题
try again
很多人说这事苹果爸爸服务器问题，重复尝试几次，总会成功的！
但是经过尝试发现如果使用Application Loader上传成功率就非常高，所以还是推荐把ipa文件导出直接用Application Loader上传。
如果Application Loader也不行，需要检查下自己的网络，有时候vpn也会提高速度。
94、当tableView占不满一屏时，去除下边多余的单元格
self.tableView.tableHeaderView = [UIView new]; self.tableView.tableFooterView = [UIView new];
95、isKindOfClass和isMemberOfClass的区别
isKindOfClass可以判断某个对象是否属于某个类，或者这个类的子类。 isMemberOfClass更加精准，它只能判断这个对象类型是否为这个类(不能判断子类)
96、__block
当一个局部变量需要在block里改变时，需要在定义时加上__block修饰，具体请看官方文档 http://developer.apple.com/library/ios/documentation/cocoa/Conceptual/Blocks/Articles/bxVariables.html#//apple_ref/doc/uid/TP40007502-CH6-SW6
97、-[ViewController aMethod:]: unrecognized selector sent to instance 0x7fe91e607fb0
这是一个经典错误，ViewController不能响应aMethod这个方法，错误原因可能viewController文件中没有实现aMethod这个方法
98、UITableView () failed to obtain a cell from its dataSource ()
这个错误原因是tableView的代理方法-tableView:cellForRowAtIndexPath:需要返回一个UITableViewCell,而你返回了一个nil。另外这个地方返回值不是UITableViewCell类型也会导致崩溃
99、约束如何做UIView动画？
-
1、把需要改的约束Constraint拖条线出来，成为属性
-
2、在需要动画的地方加入代码，改变此属性的constant属性
-
3、开始做UIView动画，动画里边调用layoutIfNeeded方法
@property (weak, nonatomic) IBOutlet NSLayoutConstraint *buttonTopConstraint;
self.buttonTopConstraint.constant = 100;
[UIView animateWithDuration:.5 animations:^{
[self.view layoutIfNeeded];
}];
100、从NSURL中拿到链接字符串
NSString *urlString = myURL.absoluteString;
101、将tableView滚动到顶部
[tableView setContentOffset:CGPointZero animated:YES]; 或者 [tableView scrollRectToVisible:CGRectMake(0, 0, 1, 1) animated:YES];
102、如果用addTarget:action:forControlEvents:方法为一个button添加了很多点击事件，在某个时刻想一次删除怎么办？只需要调用下边这句代码
[youButton removeTarget:nil action:nil forControlEvents:UIControlEventAllEvents];
103、某个字体的高度
font.lineHeight;
104、删除某个view所有的子视图
[[someView subviews] makeObjectsPerformSelector:@selector(removeFromSuperview)];
105、删除NSUserDefaults所有记录
//方法一
NSString *appDomain = [[NSBundle mainBundle] bundleIdentifier];
[[NSUserDefaults standardUserDefaults] removePersistentDomainForName:appDomain];
//方法二
- (void)resetDefaults {
NSUserDefaults * defs = [NSUserDefaults standardUserDefaults];
NSDictionary * dict = [defs dictionaryRepresentation];
for (id key in dict) {
[defs removeObjectForKey:key];
}
[defs synchronize];
}
// 方法三
[[NSUserDefaults standardUserDefaults] setPersistentDomain:[NSDictionary dictionary] forName:[[NSBundle mainBundle] bundleIdentifier]];
106、禁用系统滑动返回功能
- (void)viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
if ([self.navigationController respondsToSelector:@selector(interactivePopGestureRecognizer)]) {self.navigationController.interactivePopGestureRecognizer.delegate = self;
}
}
- (void)viewWillDisappear:(BOOL)animated {
[super viewWillDisappear:animated];
if ([self.navigationController respondsToSelector:@selector(interactivePopGestureRecognizer)]) {self.navigationController.interactivePopGestureRecognizer.delegate = nil;
}
}
- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer
{
return NO;
}
107、模拟器报错
模拟器报错
解决办法：
打开模拟器->Simulator->Reset Content and Settings...
如果不行，就重启试试！
108、自定义cell选中背景颜色
UIView *bgColorView = [[UIView alloc] init]; bgColorView.backgroundColor = [UIColor redColor]; [cell setSelectedBackgroundView:bgColorView];
109、UILabel设置内边距
子类化UILabel，重写drawTextInRect方法
- (void)drawTextInRect:(CGRect)rect {
// 边距，上左下右
UIEdgeInsets insets = {0, 5, 0, 5};
[super drawTextInRect:UIEdgeInsetsInsetRect(rect, insets)];
}
110、UILabel设置文字描边
子类化UILabel，重写drawTextInRect方法
- (void)drawTextInRect:(CGRect)rect
{
CGContextRef c = UIGraphicsGetCurrentContext();
// 设置描边宽度
CGContextSetLineWidth(c, 1);
CGContextSetLineJoin(c, kCGLineJoinRound);
CGContextSetTextDrawingMode(c, kCGTextStroke);
// 描边颜色
self.textColor = [UIColor redColor];
[super drawTextInRect:rect];
// 文本颜色
self.textColor = [UIColor yellowColor];
CGContextSetTextDrawingMode(c, kCGTextFill);
[super drawTextInRect:rect];
}
111、使用模拟器截图
快捷键command + s 或者File->Save Screen Shot
112、scrollView滚动到最下边
CGPoint bottomOffset = CGPointMake(0, scrollView.contentSize.height - scrollView.bounds.size.height); [scrollView setContentOffset:bottomOffset animated:YES];
113、UIView背景颜色渐变
UIView *view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 100)]; [self.view addSubview:view]; CAGradientLayer *gradient = [CAGradientLayer layer]; gradient.frame = view.bounds; gradient.colors = [NSArray arrayWithObjects:(id)[[UIColor blackColor] CGColor], (id)[[UIColor whiteColor] CGColor], nil]; [view.layer insertSublayer:gradient atIndex:0];
114、停止UIView动画
[yourView.layer removeAllAnimations]
115、为UIView某个角添加圆角
// 左上角和右下角添加圆角 UIBezierPath *maskPath = [UIBezierPath bezierPathWithRoundedRect:view.bounds byRoundingCorners:(UIRectCornerTopLeft | UIRectCornerBottomRight) cornerRadii:CGSizeMake(20, 20)]; CAShapeLayer *maskLayer = [CAShapeLayer layer]; maskLayer.frame = view.bounds; maskLayer.path = maskPath.CGPath; view.layer.mask = maskLayer;
116、删除Xcode Derived data缓存数据
依次点击Xcode -> Preferences -> location，然后点击 Derived data路径后到小箭头，删除这个文件夹下的数据就可以了，如图
Xcode Derived data
117、将一个view放置在其兄弟视图的最上面
[parentView bringSubviewToFront:yourView]
118、将一个view放置在其兄弟视图的最下面
[parentView sendSubviewToBack:yourView]
119、让手机震动一下
倒入框架 #import AudioServicesPlayAlertSound(kSystemSoundID_Vibrate); 或者 AudioServicesPlaySystemSound(kSystemSoundID_Vibrate);
120、layoutSubviews方法什么时候调用？
-
1、init方法不会调用
-
2、addSubview方法等时候会调用
-
3、bounds改变的时候调用
-
4、scrollView滚动的时候会调用scrollView的layoutSubviews方法(所以不建议在scrollView的layoutSubviews方法中做复杂逻辑)
-
5、旋转设备的时候调用
-
6、子视图被移除的时候调用
参考请看：http://blog.logichigh.com/2011/03/16/when-does-layoutsubviews-get-called/
121、让UILabel在指定的地方换行
// 换行符为\n,在需要换行的地方加上这个符号即可，如 label.numberOfLines = 0; label.text = @"此处\n换行";
122、摇一摇功能
1、打开摇一摇功能 [UIApplication sharedApplication].applicationSupportsShakeToEdit = YES; 2、让需要摇动的控制器成为第一响应者 [self becomeFirstResponder]; 3、实现以下方法 // 开始摇动 - (void)motionBegan:(UIEventSubtype)motion withEvent:(UIEvent *)event // 取消摇动 - (void)motionCancelled:(UIEventSubtype)motion withEvent:(UIEvent *)event // 摇动结束 - (void)motionEnded:(UIEventSubtype)motion withEvent:(UIEvent *)event
123、获取图片大小
CGFloat imageWidth = image.size.width; CGFloat imageHeight = imageWidth * image.scale;
124、获取view的坐标在整个window上的位置
// v上的(0, 0)点在toView上的位置 CGPoint point = [v convertPoint:CGPointMake(0, 0) toView:[UIApplication sharedApplication].windows.lastObject]; 或者 CGPoint point = [v.superview convertPoint:v.frame.origin toView:[UIApplication sharedApplication].windows.lastObject];
125、提交App Store审核程序限制
您的应用程序的未压缩大小必须小于4GB。每个Mach-O可执行文件（例如app_name.app/app_name）不能超过这些限制：
对于MinimumOSVersion小于7.0的应用程序：TEXT二进制文件中所有部分的总数最多为80 MB 。
对于MinimumOSVersion7.x到8.x的应用程序：TEXT对于二进制文件中每个体系结构片段的每个片段，最大为60 MB 。
对于MinimumOSVersion9.0或更高版本的应用程序：__TEXT二进制文件中所有部分的总数最多为500 MB 。参阅：iTunes Connect开发者指南
126、修改UISegmentedControl的字体大小
[segment setTitleTextAttributes:@{NSFontAttributeName : [UIFont systemFontOfSize:15.0f]} forState:UIControlStateNormal];
127、在非ViewController的地方弹出UIAlertController对话框
// 最好抽成一个分类
UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"Title" message:@"message" preferredStyle:UIAlertControllerStyleAlert];
//...
id rootViewController = [UIApplication sharedApplication].delegate.window.rootViewController;
if([rootViewController isKindOfClass:[UINavigationController class]])
{
rootViewController = ((UINavigationController *)rootViewController).viewControllers.firstObject;
}
if([rootViewController isKindOfClass:[UITabBarController class]])
{
rootViewController = ((UITabBarController *)rootViewController).selectedViewController;
}
[rootViewController presentViewController:alertController animated:YES completion:nil];
128、获取一个view所属的控制器
// view分类方法
- (UIViewController *)belongViewController {
for (UIView *next = [self superview]; next; next = next.superview) {
UIResponder* nextResponder = [next nextResponder];
if ([nextResponder isKindOfClass:[UIViewController class]]) {
return (UIViewController *)nextResponder;
}
}
return nil;
}
129、UIImage和base64互转
// view分类方法
- (NSString *)encodeToBase64String:(UIImage *)image {
return [UIImagePNGRepresentation(image) base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];
}
- (UIImage *)decodeBase64ToImage:(NSString *)strEncodeData {
NSData *data = [[NSData alloc]initWithBase64EncodedString:strEncodeData options:NSDataBase64DecodingIgnoreUnknownCharacters];
return [UIImage imageWithData:data];
}
130、UIWebView设置背景透明
[webView setBackgroundColor:[UIColor clearColor]]; [webView setOpaque:NO];
131、判断NSDate是不是今天
NSDateComponents *otherDay = [[NSCalendar currentCalendar] components:NSCalendarUnitEra | NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitDay fromDate:aDate];
NSDateComponents *today = [[NSCalendar currentCalendar] components:NSCalendarUnitEra | NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitDay fromDate:[NSDate date]];
if([today day] == [otherDay day] &&
[today month] == [otherDay month] &&
[today year] == [otherDay year] &&
[today era] == [otherDay era]) {
// 是今天
}
132、设置tableView分割线颜色
[self.tableView setSeparatorColor:[UIColor myColor]];
133、设置屏幕方向
[[UIDevice currentDevice] setValue:@(UIInterfaceOrientationLandscapeLeft) forKey:@"orientation"];
134、比较两个颜色是否相等
- (BOOL)isEqualToColor:(UIColor *)otherColor {
CGColorSpaceRef colorSpaceRGB = CGColorSpaceCreateDeviceRGB();
6
UIColor *(^convertColorToRGBSpace)(UIColor*) = ^(UIColor *color) {
if (CGColorSpaceGetModel(CGColorGetColorSpace(color.CGColor)) == kCGColorSpaceModelMonochrome) {
const CGFloat *oldComponents = CGColorGetComponents(color.CGColor);
CGFloat components[4] = {oldComponents[0], oldComponents[0], oldComponents[0], oldComponents[1]};
CGColorRef colorRef = CGColorCreate( colorSpaceRGB, components );
6
UIColor *color = [UIColor colorWithCGColor:colorRef];
CGColorRelease(colorRef);
return color;
} else
return color;
};
6
UIColor *selfColor = convertColorToRGBSpace(self);
otherColor = convertColorToRGBSpace(otherColor);
CGColorSpaceRelease(colorSpaceRGB);
return [selfColor isEqual:otherColor];
}
135、tableViewCell分割线顶到头
- (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath {
[cell setSeparatorInset:UIEdgeInsetsZero];
[cell setLayoutMargins:UIEdgeInsetsZero];
cell.preservesSuperviewLayoutMargins = NO;
}
- (void)viewDidLayoutSubviews {
[self.tableView setSeparatorInset:UIEdgeInsetsZero];
[self.tableView setLayoutMargins:UIEdgeInsetsZero];
}
136、不让控制器的view随着控制器的xib拉伸或压缩
self.view.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
137、cocoaPods报错 : [!] Unable to add a source with url https://github.com/CocoaPods/Specs.git named master-1.
You can try adding it manually in ~/.cocoapods/repos or via pod repo add.
解决方法：这是因为电脑里安装了另外一个Xcode导致cocoapods找不到路径了
在终端执行 sudo xcode-select -switch /Applications/Xcode.app 即可
138、安装cocoapods的时候出现 ERROR: While executing gem ... (Errno::EPERM)
Operation not permitted - /usr/bin/pod
解决办法：直接在终端执行 sudo gem install -n /usr/local/bin cocoapods
139、在状态栏增加网络请求的菊花，类似safari加载网页的时候状态栏菊花
[UIApplication sharedApplication].networkActivityIndicatorVisible = YES;
140、检查一个rect是否包含一个point
// point是否在rect内 BOOL isContains = CGRectContainsPoint(rect, point);
141、在指定的宽度下，让UILabel自动设置最佳font
label.adjustsFontSizeToFitWidth = YES;
142、将一个image保存在相册中
UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil);
或者
#import
[[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
PHAssetChangeRequest *changeRequest = [PHAssetChangeRequest creationRequestForAssetFromImage:image];
changeRequest.creationDate = [NSDate date];
} completionHandler:^(BOOL success, NSError *error) {
if (success) {
NSLog(@"successfully saved");
}
else {
NSLog(@"error saving to photos: %@", error);
}
}];
143、修改cell.imageView的大小
UIImage *icon = [UIImage imageNamed:@""]; CGSize itemSize = CGSizeMake(30, 30); UIGraphicsBeginImageContextWithOptions(itemSize, NO ,0.0); CGRect imageRect = CGRectMake(0.0, 0.0, itemSize.width, itemSize.height); [icon drawInRect:imageRect]; cell.imageView.image = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext();
144、为一个view添加虚线边框
CAShapeLayer *border = [CAShapeLayer layer]; border.strokeColor = [UIColor colorWithRed:67/255.0f green:37/255.0f blue:83/255.0f alpha:1].CGColor; border.fillColor = nil; border.lineDashPattern = @[@4, @2]; border.path = [UIBezierPath bezierPathWithRect:view.bounds].CGPath; border.frame = view.bounds; [view.layer addSublayer:border];
145、UITextView中打开或禁用复制，剪切，选择，全选等功能
// 继承UITextView重写这个方法
- (BOOL)canPerformAction:(SEL)action withSender:(id)sender
{
// 返回NO为禁用，YES为开启
// 粘贴
if (action == @selector(paste:)) return NO;
// 剪切
if (action == @selector(cut:)) return NO;
// 复制
if (action == @selector(copy:)) return NO;
// 选择
if (action == @selector(select:)) return NO;
// 选中全部
if (action == @selector(selectAll:)) return NO;
// 删除
if (action == @selector(delete:)) return NO;
// 分享
if (action == @selector(share)) return NO;
return [super canPerformAction:action withSender:sender];
}
由于简书对文章篇幅有一定限制，只能分篇书写，感兴趣的朋友可以持续关注，后边还有很多！文章中的代码有问题可以直接私信我或者加入我们的技术群一起交流。
开发经验集锦。
声明：以上内容来自用户投稿及互联网公开渠道收集整理发布，本网站不拥有所有权，未作人工编辑处理，也不承担相关法律责任，若内容有误或涉及侵权可进行投诉： 投诉/举报 工作人员会在5个工作日内联系你，一经查实，本站将立刻删除涉嫌侵权内容。