Swift:applicationDidEnterBackground 计时器 [英] Swift: applicationDidEnterBackground timer

问题描述

我需要在applicationDidEnterBackground方法中添加一个NSTimer；我尝试添加

I need to add an NSTimer in the applicationDidEnterBackground method; I tried adding

NSTimer.scheduledTimerWithTimeInterval(5, target: self, selector: Selector("test"), userInfo: nil, repeats: true)

但它不起作用.

推荐答案

根据您的评论，您的声明应如下所示:

According to your comments, your declaration should look something like this:

NSTimer.scheduledTimerWithTimeInterval(60, target: self, selector: "test:", userInfo: nil, repeats: false)

注意两点:

1. 您可以直接将字符串文字传递给选择器参数(不需要 Selector() 语法)，但这当然是可选的.

2. NSTimer 期望选择器在达到零时触发，以接受一个参数(NSTimer 类型)，它将传递给它自己，所以一个冒号 (:) 需要在选择器名称的末尾，以指示它将接受一个参数.

1. You can pass a string literal to the selector parameter directly (no need for Selector() syntax), but this is of course optional.

2. The NSTimer expects the selector that will fire when it hits zero to accept a parameter (of type NSTimer) to which it will pass itself, so a colon (:) is needed at the end of the selector name to indicate that it will take a parameter.

选择器应具有以下签名:timerFireMethod:(包括一个冒号来表示该方法需要一个参数).这timer 将自身作为参数传递，因此该方法将采用以下模式:- (void)timerFireMethod:(NSTimer *)timer

The selector should have the following signature: timerFireMethod: (including a colon to indicate that the method takes an argument). The timer passes itself as the argument, thus the method would adopt the following pattern: - (void)timerFireMethod:(NSTimer *)timer

_{来自 NSTimer 文档.}

因此，您还必须稍微修改函数声明:

Because of this, you'll also have to modify your function declaration a bit:

func test(timer: NSTimer) {
    // Proceed to grab location from background
}

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