wpf - 使用RenderTargetBitmap的WPF内存泄漏？

我对WPF代码中的内存泄漏感到困惑。我正在将一些3D几何体渲染到多个RenderTargetBitmap，然后将每个3D几何体渲染到一个大型的主RenderTargetBitmap。但是，当我这样做时，我遇到一两分钟的内存泄漏，崩溃了我的应用程序。

我在下面的简化代码中重现了该错误。

   private void timer1_Tick(object sender, EventArgs e) {
       // if first time, create final stitch bitmap and set UI image source
       if (stitch == null) {
           stitch = new RenderTargetBitmap(1280, 480, 96, 96, PixelFormats.Pbgra32);
           myImage.Source = stitch;
       }

       // create visual and render to img1
       Rect rect = new Rect(new Point(160, 100), new Size(320, 80));
       DrawingVisual dvis = new DrawingVisual();
       using (DrawingContext dc = dvis.RenderOpen()) {
           dc.DrawRectangle(System.Windows.Media.Brushes.LightBlue, (System.Windows.Media.Pen)null, rect);
       }
       RenderTargetBitmap img1 = new RenderTargetBitmap(640, 480, 96, 96, PixelFormats.Pbgra32);
       img1.Render(dvis);

       // create visual and render to final stitch
       DrawingVisual vis = new DrawingVisual();
       using (DrawingContext dc = vis.RenderOpen()) {
           dc.DrawImage(img1, new Rect(0, 0, 640, 480));
       }

       stitch.Clear();
       stitch.Render(vis);
   }

谁能看到任何明显的错误地方？为什么这段代码会有严重的内存泄漏？

最佳答案

如果使用资源监视器监视RenderTargetBitmap类的行为，则每次看到该类时，您都会看到丢失500KB的内存。我对您问题的回答是：不要多次使用RenderTargetBitmap类

您甚至无法释放RenderTargetBitmap的“已用内存”。

如果确实需要使用RenderTargetBitmap类，只需在代码末尾添加这些行。

GC.Collect()
GC.WaitForPendingFinalizers()
GC.Collect()

这也许可以解决您的问题：

private void timer1_Tick(object sender, EventArgs e) {
       // if first time, create final stitch bitmap and set UI image source
       if (stitch == null) {
           stitch = new RenderTargetBitmap(1280, 480, 96, 96, PixelFormats.Pbgra32);
           myImage.Source = stitch;
       }

       // create visual and render to img1
       Rect rect = new Rect(new Point(160, 100), new Size(320, 80));
       DrawingVisual dvis = new DrawingVisual();
       using (DrawingContext dc = dvis.RenderOpen()) {
           dc.DrawRectangle(System.Windows.Media.Brushes.LightBlue, (System.Windows.Media.Pen)null, rect);
       }
       RenderTargetBitmap img1 = new RenderTargetBitmap(640, 480, 96, 96, PixelFormats.Pbgra32);
       img1.Render(dvis);

       // create visual and render to final stitch
       DrawingVisual vis = new DrawingVisual();
       using (DrawingContext dc = vis.RenderOpen()) {
           dc.DrawImage(img1, new Rect(0, 0, 640, 480));
       }

        GC.Collect();
        GC.WaitForPendingFinalizers();
        GC.Collect();
       stitch.Clear();
       stitch.Render(vis);
}