RenderTargetBitmap GDI句柄在“主详细信息”视图中泄漏

我有一个带有Master Details视图的应用程序。当您从"主"列表中选择一个项目时，它会用一些图像（通过RenderTargetBitmap创建）填充"详细信息"区域。

每次我从列表中选择不同的主项时，我的应用程序正在使用的GDI句柄的数量（如Process Explorer中所报告的）都会增加，最终会下降（有时会锁定）到10000个正在使用的GDI句柄。

我不知道如何解决这个问题，所以任何关于我做错了什么的建议（或者只是关于如何获得更多信息的建议）都将不胜感激。

我在一个名为"DoesThisLeak"的新WPF应用程序（.NET 4.0）中将我的应用程序简化为以下内容：

在主窗口.xaml.cs 中

public partial class MainWindow : Window
{
    public MainWindow()
    {
        ViewModel = new MasterViewModel();
        InitializeComponent();
    }
    public MasterViewModel ViewModel { get; set; }
}
public class MasterViewModel : INotifyPropertyChanged
{
    private MasterItem selectedMasterItem;
    public IEnumerable<MasterItem> MasterItems
    {
        get
        {
            for (int i = 0; i < 100; i++)
            {
                yield return new MasterItem(i);
            }
        }
    }
    public MasterItem SelectedMasterItem
    {
        get { return selectedMasterItem; }
        set
        {
            if (selectedMasterItem != value)
            {
                selectedMasterItem = value;
                if (PropertyChanged != null)
                {
                    PropertyChanged(this, new PropertyChangedEventArgs("SelectedMasterItem"));
                }
            }
        }
    }
    public event PropertyChangedEventHandler PropertyChanged;
}
public class MasterItem
{
    private readonly int seed;
    public MasterItem(int seed)
    {
        this.seed = seed;
    }
    public IEnumerable<ImageSource> Images
    {
        get
        {
            GC.Collect(); // Make sure it's not the lack of collections causing the problem
            var random = new Random(seed);
            for (int i = 0; i < 150; i++)
            {
                yield return MakeImage(random);
            }
        }
    }
    private ImageSource MakeImage(Random random)
    {
        const int size = 180;
        var drawingVisual = new DrawingVisual();
        using (DrawingContext drawingContext = drawingVisual.RenderOpen())
        {
            drawingContext.DrawRectangle(Brushes.Red, null, new Rect(random.NextDouble() * size, random.NextDouble() * size, random.NextDouble() * size, random.NextDouble() * size));
        }
        var bitmap = new RenderTargetBitmap(size, size, 96, 96, PixelFormats.Pbgra32);
        bitmap.Render(drawingVisual);
        bitmap.Freeze();
        return bitmap;
    }
}

在主窗口.xaml 中

<Window x:Class="DoesThisLeak.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="900" Width="1100"
        x:Name="self">
  <Grid DataContext="{Binding ElementName=self, Path=ViewModel}">
    <Grid.ColumnDefinitions>
      <ColumnDefinition Width="210"/>
      <ColumnDefinition Width="*"/>
      <ColumnDefinition/>
    </Grid.ColumnDefinitions>
    <ListBox Grid.Column="0" ItemsSource="{Binding MasterItems}" SelectedItem="{Binding SelectedMasterItem}"/>
    <ItemsControl Grid.Column="1" ItemsSource="{Binding Path=SelectedMasterItem.Images}">
      <ItemsControl.ItemTemplate>
        <DataTemplate>
          <Image Source="{Binding}"/>
        </DataTemplate>
      </ItemsControl.ItemTemplate>
    </ItemsControl>
  </Grid>
</Window>

如果单击列表中的第一个项目，然后按住向下光标键，则可以重现问题。

从看！在带有SOS的WinDbg中的gcroot中，我找不到任何东西来保持这些RenderTargetBitmap对象的活动，但如果我执行!dumpheap -type System.Windows.Media.Imaging.RenderTargetBitmap，它仍然显示数千个尚未收集的对象。

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

A first chance exception of type 'System.Runtime.InteropServices.COMException' occurred in PresentationCore.dll
A first chance exception of type 'System.Runtime.InteropServices.COMException' occurred in PresentationCore.dll
A first chance exception of type 'System.Reflection.TargetInvocationException' occurred in mscorlib.dll
System.Windows.Data Error: 8 : Cannot save value from target back to source. BindingExpression:Path=SelectedMasterItem; DataItem='MasterViewModel' (HashCode=28657291); target element is 'ListBox' (Name=''); target property is 'SelectedItem' (type 'Object') COMException:'System.Runtime.InteropServices.COMException (0x88980003): Exception from HRESULT: 0x88980003
   at System.Windows.Media.Imaging.RenderTargetBitmap.FinalizeCreation()

public ObservableCollection<ImageSource> Images
{
    get 
    {
        return new ObservableCollection<ImageSource>(ImageSources);
    }
}
IEnumerable<ImageSource> ImageSources
{
    get
    {
        var random = new Random(seed);
        for (int i = 0; i < 150; i++)
        {
            yield return MakeImage(random);
        }
    }
}