功能导致屏幕闪现冻结

Question

我有一个并不那么复杂的函数，但由于某种原因，每次我调用它时，它都会冻结屏幕大约四分之一秒。该功能基于计时器，每秒部署一次，因此可能会让用户感到非常烦人。

该函数基本上获取屏幕的屏幕截图，通过比较 10 个像素来检查它是否正在寻找的屏幕，如果是屏幕则返回 true，否则返回 false：

ClassName.CheckScreen(CaptureScreen(),ClassName.Pxarr1); //Capture screen isn't the problem. It gave me no freezes in an endless loop.

这就是类：

class ClassName
{
    public static Pixel[] Pxarr1 = new[]
    {
        new Pixel(Color.FromArgb(255, 204, 204, 170), new Point(15, 145)),
        new Pixel(Color.FromArgb(255, 221, 204, 187), new Point(20, 460)),
        new Pixel(Color.FromArgb(255, 221, 204, 187), new Point(20, 545)),
        new Pixel(Color.FromArgb(255, 204, 187, 170), new Point(15, 150)),
        new Pixel(Color.FromArgb(255, 221, 204, 187), new Point(22, 190)),
        new Pixel(Color.FromArgb(255, 204, 204, 187), new Point(25, 540)),
        new Pixel(Color.FromArgb(255, 204, 187, 153), new Point(22, 61)),
        new Pixel(Color.FromArgb(255, 221, 204, 170), new Point(23, 563)),
        new Pixel(Color.FromArgb(255, 204, 187, 153), new Point(23, 47)),
        new Pixel(Color.FromArgb(255, 204, 204, 187), new Point(23, 463)),

    };

    public static Pixel[] Pxarr2 = new[]
    {
        new Pixel(Color.FromArgb(255, 221, 255, 119), new Point(80, 120)),
        new Pixel(Color.FromArgb(255, 51, 119, 221), new Point(180, 525)),
        new Pixel(Color.FromArgb(255, 204, 170, 85), new Point(630, 455)),
        new Pixel(Color.FromArgb(255, 85, 153, 17), new Point(707, 177)),
        new Pixel(Color.FromArgb(255, 255, 153, 34), new Point(520, 440)),
        new Pixel(Color.FromArgb(255, 255, 238, 51), new Point(150, 325)),
        new Pixel(Color.FromArgb(255, 0, 85, 255), new Point(455, 70)),
        new Pixel(Color.FromArgb(255, 255, 221, 51), new Point(685, 285)),
        new Pixel(Color.FromArgb(255, 17, 17, 17), new Point(547, 369)),
        new Pixel(Color.FromArgb(255, 170, 170, 136), new Point(500, 545)),

    };

    public static Pixel[] Pxarr3 = new[]
    {
        new Pixel(Color.FromArgb(255, 238, 238, 238), new Point(353, 223)),
        new Pixel(Color.FromArgb(255, 28, 33, 49), new Point(428, 198)),
        new Pixel(Color.FromArgb(255, 85, 85, 85), new Point(462, 314)),
        new Pixel(Color.FromArgb(255, 221, 221, 238), new Point(450, 450)),
        new Pixel(Color.FromArgb(255, 102, 102, 102), new Point(384, 349)),
        new Pixel(Color.FromArgb(255, 204, 204, 204), new Point(406, 248)),
        new Pixel(Color.FromArgb(255, 221, 221, 221), new Point(464, 453)),
        new Pixel(Color.FromArgb(255, 255, 204, 17), new Point(413, 198)),
        new Pixel(Color.FromArgb(255, 204, 204, 204), new Point(343, 447)),
        new Pixel(Color.FromArgb(255, 255, 255, 255), new Point(403, 457)),

    };

    public static Pixel[] Pxarr4 = new[]
    {
        new Pixel(Color.FromArgb(255, 204, 170, 136), new Point(120, 227)),
        new Pixel(Color.FromArgb(255, 221, 187, 153), new Point(502, 170)),
        new Pixel(Color.FromArgb(255, 119, 85, 34), new Point(692, 243)),
        new Pixel(Color.FromArgb(255, 238, 221, 187), new Point(211, 169)),
        new Pixel(Color.FromArgb(255, 187, 170, 136), new Point(272, 238)),
        new Pixel(Color.FromArgb(255, 170, 153, 119), new Point(696, 64)),
        new Pixel(Color.FromArgb(255, 136, 85, 17), new Point(306, 242)),
        new Pixel(Color.FromArgb(255, 187, 170, 119), new Point(115, 236)),
        new Pixel(Color.FromArgb(255, 204, 187, 153), new Point(310, 183)),
        new Pixel(Color.FromArgb(255, 153, 102, 34), new Point(647, 245)),

    };

    public static Pixel[] Pxarr5 = new[]
    {
        new Pixel(Color.FromArgb(255, 255, 238, 221), new Point(376, 150)),
        new Pixel(Color.FromArgb(255, 255, 238, 221), new Point(376, 350)),

        new Pixel(Color.FromArgb(255, 255, 238, 221), new Point(506, 150)),
        new Pixel(Color.FromArgb(255, 255, 238, 221), new Point(506, 350)),

        new Pixel(Color.FromArgb(255, 255, 238, 221), new Point(246, 150)),
        new Pixel(Color.FromArgb(255, 255, 238, 221), new Point(246, 350))
    };

    public static bool CheckScreen(Bitmap img, Pixel[] samples)
    {
        int verifiedpixels = 0;
        for (int i = 0; i < samples.Length; i++)
        {
            Color c = img.GetPixel(samples[i].Location.X, samples[i].Location.Y);
            if (c == samples[i].Color)
                    verifiedpixels++;
        }
        return verifiedpixels >= (samples.Length * 0.6);
    }

}

注意：100 个循环 for 语句的速度是CaptureScreen() 与使用文件中的图像相比。 （4 秒与 2 秒）

但是，我仍然不明白为什么这个函数会导致冻结，即使使用文件中的图像也是如此。

Answer 1

由于您使用的是计时器，因此它不应冻结 UI，除非您使用 System.Windows.Forms.Timer 它将在 UI 线程上执行回调。而是使用 System.Timers.Timer 或 System.Threading.Timer。
System.Timers.Timer 示例：

private System.Timers.Timer _checkPixelsTimer = new System.Timers.Timer();

public Form1()
{
    InitializeComponents();

    _checkPixelsTimer.Intervla = 1000;//one second
    _checkPixelsTimer.AutoReset = true;
    _checkPixelsTimer.Elapced += OnCheckPixelsTimerElapced;
    _checkPixelsTimer.Start();
}

private void OnCheckPixelsTimerElapced(object sender, System.Timer.ElapcedEventArgs e)
{
    if (ClassName.CheckScreen(CaptureScreen(),ClassName.Pxarr1))
    {
        MethodInvoker method = new MethodInvoker(() => { /*code that relays on the UI thread */ });
        if (this.InvokeRequired)
        {
            this.Invoke(method); 
        }
        else
        {
            method();
        }
    }
}

编辑：更新代码以预览如何在 UI 线程调用函数。

Answer 2

GetPixel() 和 SetPixel() 是出了名的慢。

使用替代方法，例如 LockBits()/UnlockBits() 技术。请参阅在 C# 中快速使用位图