最近做项目遇到一个小问题，获取码证码，通常这种界面直接用xib来布局这个注册页面，以往用的是纯代码，然后发现了一个小bug，以前用纯代码写的获取验证码这个功能正常的，但是现在用xib拖拽的按钮，虽然可以实现，但是文字会闪烁，这到底是为什么纯代码没有问题，xib就出现这个问题呢？我也不知道，其实这里第一次写这个博客，写得有点烂，先上代码

#import "ViewController.h"

@interface ViewController ()

/* 时间 */

@property (nonatomic, assign) int timeCount;

/* 定时器 */

@property (nonatomic, strong) NSTimer *timer;

/* 按钮 */

@property (nonatomic, weak) UIButton *messageButton;

@end

@implementation ViewController

- (void)viewDidLoad {

    [super viewDidLoad];

    self.view.backgroundColor = [UIColor whiteColor];

    //创建按钮

    UIButton *btn = [[UIButton alloc] init];

    [btn addTarget:self action:@selector(sendMessageClick) forControlEvents:UIControlEventTouchUpInside];

    [btn setTitle:@"获取码证码" forState:UIControlStateNormal];

    btn.frame = CGRectMake(100, 100, 200, 40);

    [btn setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];

    btn.backgroundColor = [UIColor redColor];

    [self.view addSubview:btn];

    self.messageButton = btn;

}

//侦听

- (void)sendMessageClick

{

    self.messageButton.backgroundColor = [UIColor grayColor];

    self.messageButton.userInteractionEnabled = NO;

    //开始倒计时

    [self beginCalculationTime];

}

//开始倒计时

- (void)beginCalculationTime

{

    self.timeCount = 10;

    [self.messageButton setTitle:@"重新获取(60)" forState:UIControlStateNormal];

    self.timer = [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(refreshTime) userInfo:nil repeats:YES];

    [self.timer fire];

}

//timer

- (void)refreshTime

{

    self.label.text = [NSString stringWithFormat:@"重新获取(%ld)",(long)self.timeCount];

    self.timeCount -= 1;

    [self.messageButton setTitle:[NSString stringWithFormat:@"重新获取(%ld)",(long)self.timeCount] forState:UIControlStateNormal];

    if (self.timeCount == 0) {

        [self.messageButton setTitle:@"重新获取" forState:UIControlStateNormal];

        [self.timer invalidate];

        self.messageButton.userInteractionEnabled = YES;

        self.messageButton.backgroundColor = [UIColor redColor];

    }

}

@end

简单的“获取验证码”的按钮功能实现