1. 设置背景色

我以白色的背景色为例，下面看看代码：

//1. 设置背景颜色    //设置背景图是为了去掉上下黑线    self.customSearchBar.backgroundImage = [[UIImage alloc] init];    // 设置SearchBar的颜色主题为白色    self.customSearchBar.barTintColor = [UIColor whiteColor];

2. 设置边框颜色和圆角

//2. 设置圆角和边框颜色    UITextField *searchField = [self.customSearchBar valueForKey:@"searchField"];    if (searchField) {        [searchField setBackgroundColor:[UIColor whiteColor]];        searchField.layer.cornerRadius = 14.0f;        searchField.layer.borderColor = [UIColor colorWithRed:247/255.0 green:75/255.0 blue:31/255.0 alpha:1].CGColor;        searchField.layer.borderWidth = 1;        searchField.layer.masksToBounds = YES;    }

这段代码有个特别的地方就是通过KVC获得到UISearchBar的私有变量

searchField（类型为UITextField），设置SearchBar的边框颜色和圆角实际上也就变成了设置searchField的边框颜色和圆角，你可以试试直接设置SearchBar.layer.borderColor和cornerRadius，会发现这样做是有问题的。 

3. 设置按钮（取消按钮）的文字和文字颜色

//3. 设置按钮文字和颜色    [self.customSearchBar fm_setCancelButtonTitle:@"取消"];    self.customSearchBar.tintColor = [UIColor colorWithRed:86/255.0 green:179/255.0 blue:11/255.0 alpha:1];    //修正光标颜色    [searchField setTintColor:[UIColor blackColor]];//其中fm_setCancelButtonTitle是我写的UISearchBar一个分类的方法- (void)fm_setCancelButtonTitle:(NSString *)title {    if (IS_IOS9) {        [[UIBarButtonItem appearanceWhenContainedInInstancesOfClasses:@[[UISearchBar class]]] setTitle:title];    }else {        [[UIBarButtonItem appearanceWhenContainedIn:[UISearchBar class], nil] setTitle:title];    }}

4. 设置输入框的文字颜色和字体

//4. 设置输入框文字颜色和字体    [self.customSearchBar fm_setTextColor:[UIColor blackColor]];    [self.customSearchBar fm_setTextFont:[UIFont systemFontOfSize:14]];//下面两个方法是UISearchBar分类代码- (void)fm_setTextColor:(UIColor *)textColor {    if (IS_IOS9) {        [UITextField appearanceWhenContainedInInstancesOfClasses:@[[UISearchBar class]]].textColor = textColor;    }else {        [[UITextField appearanceWhenContainedIn:[UISearchBar class], nil] setTextColor:textColor];    }}- (void)fm_setCancelButtonTitle:(NSString *)title {    if (IS_IOS9) {        [[UIBarButtonItem appearanceWhenContainedInInstancesOfClasses:@[[UISearchBar class]]] setTitle:title];    }else {        [[UIBarButtonItem appearanceWhenContainedIn:[UISearchBar class], nil] setTitle:title];    }}

自定义UISearchBar外观