c# – 使用Windows服务进行屏幕截图

当我要开始服务时,它说我无法启动服务.当我检查Windows日志时,它提到了以下错误.

Service cannot be started. System.ComponentModel.Win32Exception (0x80004005): The handle is invalid
   at System.Drawing.Graphics.CopyFromScreen(Int32 sourceX, Int32 sourceY, Int32 destinationX, Int32 destinationY, Size blockRegionSize, CopyPixelOperation copyPixelOperation)
   at ScreenCaptureService.ScreenCaptureService.TraceService() in d:\SourceControl\Test\Test\ScreenCapture\ScreenCaptureService\ScreenCaptureService.cs:line 63
   at ScreenCaptureService.ScreenCaptureService.OnStart(String[] args) in d:\SourceControl\Test\Test\ScreenCapture\ScreenCaptureService\ScreenCaptureService.cs:line 32
   at System.ServiceProcess.ServiceBase.ServiceQueuedMainCallback(Object state)

我的代码如下：

public partial class ScreenCaptureService : ServiceBase
{

    private static Bitmap bmpScreenshot;
    private static Graphics gfxScreenshot;
    System.Timers.Timer timer = new System.Timers.Timer();
    public ScreenCaptureService()
    {
        InitializeComponent();
    }

    protected override void OnStart(string[] args)
    {

        TraceService();
        timer.Elapsed += new ElapsedEventHandler(OnElapsedTime);
        timer.Interval = 300000;          
        timer.Enabled = true;
    }

    protected override void OnStop()
    {
        timer.Enabled = false;
        TraceService();
    }

    private void TraceService()
    {
        string fileName = "D:\\Screen\\abc.png";
        bmpScreenshot = new Bitmap(Screen.PrimaryScreen.Bounds.Width, Screen.PrimaryScreen.Bounds.Height, PixelFormat.Format32bppArgb);


        gfxScreenshot = Graphics.FromImage(bmpScreenshot);            
        gfxScreenshot.CopyFromScreen(Screen.PrimaryScreen.Bounds.X, Screen.PrimaryScreen.Bounds.Y, 0, 0, Screen.PrimaryScreen.Bounds.Size, CopyPixelOperation.SourceCopy);

        bmpScreenshot.Save(fileName, ImageFormat.Png);
    }

    private void OnElapsedTime(object source, ElapsedEventArgs e)
    {
        TraceService();
    }
}

我在这里错过了什么..

编辑：当我勾选允许服务与桌面交互时,它会在日志中显示以下错误.

Service cannot be started. System.Runtime.InteropServices.ExternalException (0x80004005): A generic error occurred in GDI+.
   at System.Drawing.Image.Save(String filename, ImageCodecInfo encoder, EncoderParameters encoderParams)
   at ScreenCaptureService.ScreenCaptureService.TraceService() in d:\SourceControl\Test\Test\ScreenCapture\ScreenCaptureService\ScreenCaptureService.cs:line 66
   at ScreenCaptureService.ScreenCaptureService.OnStart(String[] args) in d:\SourceControl\Test\Test\ScreenCapture\ScreenCaptureService\ScreenCaptureService.cs:line 32
   at System.ServiceProcess.ServiceBase.ServiceQueuedMainCallback(Object state)