NSTimer timerWithTimeInterval：不工作 [英] NSTimer timerWithTimeInterval: not working

问题描述

在我的项目中实现它之前，我已经用计时器创建了一个测试应用程序。
这是我第一次使用计时器。
但问题是当我使用 [NSTimer timerWithTimeInterval：target：selector：userInfo：repeats：]; 实现计时器时，它无效。
这是我的代码，
接口：

I've created a test application with timer before implementing it in my project. It was the first time I'm using timer. But the issue is when I implemented timer using [NSTimer timerWithTimeInterval: target: selector: userInfo: repeats: ]; , it is not working. Here is my code, Interface:

@interface uialertViewController : UIViewController
{

    NSTimer *timer;
}

-(void)displayAlert;
-(void)hideandview;
@end

实施：

@implementation uialertViewController
- (void)viewDidLoad {

    [self displayAlert];
    [super viewDidLoad];
}


-(void)displayAlert{

    timer = [NSTimer timerWithTimeInterval:1 target:self selector:@selector(hideandview) userInfo:nil repeats:NO];

    alert = [[UIAlertView alloc] initWithTitle:@"testing" message:@"hi hi hi" delegate:nil cancelButtonTitle:@"continue" otherButtonTitles:nil];
    [alert show];




    [alert release];
    alert = nil;

}

-(void)hideandview{

    NSLog(@"triggered");

    [alert dismissWithClickedButtonIndex:0 animated:YES];

    [alert release];

    [self displayAlert];
}

@end

然后我改变了 [NSTimer timerWithTimeInterval：target：selector：userInfo：repeats：]; with [NSTimer scheduledTimerWithTimeInterval：target ：selector：userInfo：重复：]; ，它正在运行。 timerWithTimeInterval：的问题是什么？在我的第一次实施中，我是否正在做什么？在此先感谢。

Then I Changed [NSTimer timerWithTimeInterval: target: selector: userInfo: repeats: ]; with [NSTimer scheduledTimerWithTimeInterval: target: selector:userInfo: repeats: ]; , It is working. What was the issue with timerWithTimeInterval: ? Am I mising anything in my first implementation ? Thanks in advance.

推荐答案

scheduledTimerWithTimeInterval：invocation：repeats：和 scheduledTimerWithTimeInterval：target：selector：userInfo：重复：创建自动添加到 NSRunLoop 的计时器，这意味着你不要必须自己添加它们。将它们添加到 NSRunLoop 是导致它们触发的原因。

scheduledTimerWithTimeInterval:invocation:repeats: and scheduledTimerWithTimeInterval:target:selector:userInfo:repeats: create timers that get automatically added to an NSRunLoop, meaning that you don't have to add them yourself. Having them added to an NSRunLoop is what causes them to fire.

使用 timerWithTimeInterval：调用：重复：和 timerWithTimeInterval：target：selector：userInfo：重复：，你必须手动将定时器添加到运行循环中，使用代码像这样：

With timerWithTimeInterval:invocation:repeats: and timerWithTimeInterval:target:selector:userInfo:repeats:, you have to add the timer to a run loop manually, with code like this:

[[NSRunLoop mainRunLoop] addTimer:repeatingTimer forMode:NSDefaultRunLoopMode];

此处的其他答案建议您需要致电 fire 你自己。你不这样做 - 只要计时器被置于一个运行循环就会被调用。

Other answers on here suggest that you need to call fire yourself. You don't - it will be called as soon as the timer has been put on a run loop.

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