第一步,拖兩個空間textfiled和button到storyboard上的viewcontroller上。
第二步,拖線,鏈接到.h文件中代碼如下:
@property (weak, nonatomic) IBOutlet UIButton *l_timeButton;
第三步,在,m文件中為l_timeButton設置監聽器,監聽點擊事件。
- (void)viewDidLoad {
[super viewDidLoad];
[_l_timeButton addTarget:self action:@selector(startTime) forControlEvents:UIControlEventTouchUpInside];
}
第四步,在方法“startTime”中實現倒計時功能
-(void)startTime{
__block int timeout=30; //倒計時時間
dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
dispatch_source_t _timer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0,queue);
dispatch_source_set_timer(_timer,dispatch_walltime(NULL, 0),1.0*NSEC_PER_SEC, 0); //每秒執行
dispatch_source_set_event_handler(_timer, ^{
if(timeout<=0){ //倒計時結束,關閉
dispatch_source_cancel(_timer);
dispatch_async(dispatch_get_main_queue(), ^{
//設置界面的按鈕顯示 根據自己需求設置
[_l_timeButton setTitle:@"發送驗證碼" forState:UIControlStateNormal];
_l_timeButton.userInteractionEnabled = YES;
});
}else{
int seconds = timeout % 60;
NSString *strTime = [NSString stringWithFormat:@"%.2d", seconds];
dispatch_async(dispatch_get_main_queue(), ^{
//設置界面的按鈕顯示 根據自己需求設置
//NSLog(@"____%@",strTime);
[UIView beginAnimations:nil context:nil];
[UIView setAnimationDuration:1];
[_l_timeButton setTitle:[NSString stringWithFormat:@"%@秒後重新發送",strTime] forState:UIControlStateNormal];
[UIView commitAnimations];
_l_timeButton.userInteractionEnabled = NO;
});
timeout--;
}
});
dispatch_resume(_timer);
}
好了,一個驗證碼倒計時的功能就寫好了。還有,另一種方法,後期等我研究好以後,在介介紹給大家。附上運行圖片如下: