在UserControl WPF中的PictureBox上绘制图像

时间:2013-08-08 13:37:29

标签: wpf winforms picturebox

我正在尝试使用PictureBox从我插入的相机在WindowsFormsHost上绘制图像。代码简单如下:

<Window x:Class="videoTEst.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="MainWindow" Height="583" Width="1132"
    xmlns:wf="clr-namespace:System.Windows.Forms;assembly=System.Windows.Forms">
<StackPanel Background="LightBlue" Height="513" Width="1077">
    <StackPanel HorizontalAlignment="Center" Width="450" Orientation="Horizontal">
        <Button Name="ButtonOpen" Content="Load" Click="ButtonOpen_OnClick" />
        <Button Name="ButtonLoadImage" Content="Load image" Click="ButtonLoadImage_OnClick" />
        </StackPanel>
    <StackPanel Orientation="Horizontal">
        <WindowsFormsHost Name="WinFormsHost" Height="440" Width="690" HorizontalAlignment="Left">
                <wf:PictureBox x:Name="PictureBoxvideo" SizeMode="Normal" Paint="PictureBoxvideo_Paint"></wf:PictureBox>
        </WindowsFormsHost>
        <ListBox Name="ListBoxLog" />
    </StackPanel>
</StackPanel>

我从相机中画出这样的:

 private void asyncVideoSource_NewFrame(object sender, NewFrameEventArgs eventArgs)
    {
        Image temp = PictureBoxvideo.Image;
        Bitmap bitmap = eventArgs.Frame;
        PictureBoxvideo.Image = new Bitmap(bitmap);
        if (temp != null) temp.Dispose();
        bitmap.Dispose();
   }

此代码完美无缺。

但是,当我将<Window>标签更改为<UserControl>时(因为我希望将其嵌入到我自己的UserControl中),它就不会绘制!!

为什么不在UserControl上绘画?

为什么我没有使用WPF中的Image Image的线程使用确实让人感到困惑,每当我尝试在Image上绘画时,Bitmap就被处理掉了。

1 个答案:

答案 0 :(得分:4)

而不是WindowsFormsHost中的PictureBox,您只需使用WPF图像控件:

<StackPanel Orientation="Horizontal">
    <Image x:Name="image" Height="440" Width="690" HorizontalAlignment="Left"/>
    ...
</StackPanel>

现在,您将使用this answerthis answer中所示的代码从Bitmap对象创建BitmapImage,并对Freeze进行额外调用,以便在UI线程中访问它:

Bitmap bitmap = eventArgs.Frame; // your NewFrameEventArgs
BitmapImage bitmapImage = new BitmapImage();

using (var stream = new MemoryStream())
{
    bitmap.Save(stream, ImageFormat.Bmp);
    stream.Seek(0, SeekOrigin.Begin);

    bitmapImage.BeginInit();
    bitmapImage.CacheOption = BitmapCacheOption.OnLoad;
    bitmapImage.StreamSource = stream;
    bitmapImage.EndInit();
}

bitmapImage.Freeze();

最后,您将通过调用其Dispatcher:

来更新UI线程中的Image控件
image.Dispatcher.Invoke((Action)(() => image.Source = bitmapImage));