斯威夫特：在scheduledTimerWithTimeInterval调用额外的参数(Swift

我创建了一个简单的WatchApp节拍器。我使用的NSTimer与.scheduledTimerWithTimeInterval，我有呼叫错误额外的参数“选择”

谢谢您的回答

func playBeat() {

        if(self.State == true) {
            self.State == false
            [labelPlayPause.setTitle("Pause")]
        } else {
            self.State == true
            [labelPlayPause.setTitle("Play")]
        }

        BPMValue = 10
        var BPMInt:Int = Int(BPMValue)
        let value = "\(BPMInt) BPM"
        labelBPM.setText(value)
        let aSelector: Selector = "playBeat"

        dispatch_async(dispatch_get_main_queue(), {
            NSTimer.scheduledTimerWithTimeInterval(60/self.BPMValue, target:self, selector: aSelector, userInfo:nil, repeats:false)
        })

    }

这是斯威夫特一个贫穷的错误信息！

这到底是什么意思是，你需要确保类型每个函数参数的匹配类型传递的值的。

在你的情况， BPMValue是Float ，并scheduledTimerWithTimeInterval期待和NSTimeInterval作为第一个参数。需要注意的是NSTimeInterval （ Double ）和Float是不等价的。在Objective-C，你得到一个隐式转换，这不会在雨燕发生。

尝试

NSTimer.scheduledTimerWithTimeInterval(NSTimeInterval(60/self.BPMValue), target:self, selector: aSelector, userInfo:nil, repeats:false)

作为一个侧面说明，你可以稍微更简洁与斯威夫特您的代码：

func playBeat() {

    if State {          // If State is a Bool, you can lose the '== true'
        State = false   // Must use set not comparison operator. No need to refer to 'self'.
        labelPlayPause.setTitle("Pause")
    } else {
        State = true  // Must use set not comparison operator.
        labelPlayPause.setTitle("Play")
    }

    BPMValue = 10
    var BPMInt = Int(BPMValue)    // Int Type is inferred
    let value = "\(BPMInt) BPM"
    labelBPM.setText(value)
    let aSelector: Selector = "playBeat"

    dispatch_async(dispatch_get_main_queue(), {
        NSTimer.scheduledTimerWithTimeInterval(NSTimeInterval(60/self.BPMValue), target:self, selector: aSelector, userInfo:nil, repeats:false)
    })

}