Question

更新到Swift 2.2和Xcode 7.3后，我重复的NSTimer已停止重复。

let timer = NSTimer.scheduledTimerWithTimeInterval(0.4, target: self, selector: #selector(rotate), userInfo: nil, repeats: true)
timer.fire()

选择器触发一次，然后再次开火，直到窗口关闭或最小化。

其他人？有什么建议吗？

Answer 1

定时器需要在同一个线程中始终被调度或无效，您可能在异步块内调用它吗？尝试在主队列中安排它：

public Image resizeImage(int newWidth, int newHeight, string stPhotoPath)
 {
     Image imgPhoto = Image.FromFile(stPhotoPath); 

     int sourceWidth = imgPhoto.Width;
     int sourceHeight = imgPhoto.Height;

     //Consider vertical pics
    if (sourceWidth < sourceHeight)
    {
        int buff = newWidth;

        newWidth = newHeight;
        newHeight = buff;
    }

    int sourceX = 0, sourceY = 0, destX = 0, destY = 0;
    float nPercent = 0, nPercentW = 0, nPercentH = 0;

    nPercentW = ((float)newWidth / (float)sourceWidth);
    nPercentH = ((float)newHeight / (float)sourceHeight);
    if (nPercentH < nPercentW)
    {
        nPercent = nPercentH;
        destX = System.Convert.ToInt16((newWidth -
                  (sourceWidth * nPercent)) / 2);
    }
    else
    {
        nPercent = nPercentW;
        destY = System.Convert.ToInt16((newHeight -
                  (sourceHeight * nPercent)) / 2);
    }

    int destWidth = (int)(sourceWidth * nPercent);
    int destHeight = (int)(sourceHeight * nPercent);


    Bitmap bmPhoto = new Bitmap(newWidth, newHeight,
                  PixelFormat.Format24bppRgb);

    bmPhoto.SetResolution(imgPhoto.HorizontalResolution,
                 imgPhoto.VerticalResolution);

    Graphics grPhoto = Graphics.FromImage(bmPhoto);
    grPhoto.Clear(Color.Black);
    grPhoto.InterpolationMode =
        System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;

    grPhoto.DrawImage(imgPhoto,
        new Rectangle(destX, destY, destWidth, destHeight),
        new Rectangle(sourceX, sourceY, sourceWidth, sourceHeight),
        GraphicsUnit.Pixel);

    grPhoto.Dispose();
    imgPhoto.Dispose();
    return bmPhoto;
}

Answer 2

func startTimer() {
    let timer = NSTimer(timeInterval: 1, target: self, selector: #selector(MainViewController.updateLabel), userInfo: nil, repeats: true)
    NSRunLoop.currentRunLoop().addTimer(timer, forMode: NSRunLoopCommonModes)
}

这适用于Swift 2.2 苹果文档没有提及dispatch_async的任何内容。有没有理由使用它......只是好奇......还在学习

使用timerWithTimeInterval：invocation：repeats：或timerWithTimeInterval：target：selector：userInfo：repeats：class方法创建计时器对象而不在运行循环上调度它。（创建它之后，必须通过调用相应NSRunLoop对象的addTimer：forMode：方法手动将计时器添加到运行循环中。）

Answer 3

    dispatch_async(dispatch_get_main_queue()) {
        self.timer = NSTimer(timeInterval:1.0, target:self, selector: #selector(self.rotate), userInfo:nil, repeats:true)
        NSRunLoop.currentRunLoop().addTimer(self.timer!, forMode: NSRunLoopCommonModes)
    }

这是一个线程问题，也没有在NSRunLoop中自动添加或处理。在同一个线程上手动执行此操作修复它。

感谢大家的帮助和建议。

更新到Xcode 7.3 / Swift 2.2后，计时器停止工作

3 个答案: