如何从WPF图像控制中捕获图像？ [英] How Do I Capture Image From WPF Image Control?

问题描述

我的页面中有关于图像的代码。

Hi,

I have this code about an image in my page.

<!--<Border BorderThickness="5" BorderBrush="#FF000000">-->
                    <Image  Height="304" HorizontalAlignment="Left" Stretch="Fill" VerticalAlignment="Top" Width="356" Margin="108,435,0,0"  />
            <!--</Border>-->

在我的图像框中，我有一个图像，但是无论如何都要捕获图像？



需要帮助。在此先感谢。

Inside my image box, I have an image, but is there anyway to capture the image?

Help needed. Thanks in advance.

推荐答案

一种方法是创建 RenderBitmapTarget 并将源图像绘制到其上。然后使用它作为另一个图像的来源。



考虑这个例子;

One approach could be to create a RenderBitmapTarget and draw the source image onto that. And then use that as the source of another Image.

Consider this example;

<window x:class="WpfApplication9.MainWindow" xmlns:x="#unknown">
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MyAwesomeWindow" Height="350" Width="525">
    <grid>
        <grid.rowdefinitions>
            <rowdefinition height="*" />
            <rowdefinition height="*" />
            <rowdefinition height="Auto" />
        </grid.rowdefinitions>       
        <image x:name="Src" grid.row="0" source="C:\Temp\someimage.png" />
        <image x:name="Dst" grid.row="1" />
        <button grid.row="2" content="Do it!" click="ButtonBase_OnClick" />
    </grid>
</window>

支持代码为;

With the backing code of;

using System.Windows;
using System.Windows.Media.Imaging;
using System.Windows.Media;

namespace WpfApplication9 {
    public partial class MainWindow : Window {
        public MainWindow() {
            InitializeComponent();
        }

        private void ButtonBase_OnClick(object sender, RoutedEventArgs e) {
            var visual = new DrawingVisual();
            var context = visual.RenderOpen();

            // Copy source image over
            context.DrawImage(Src.Source, new Rect(0, 0, Src.Source.Width, Src.Source.Height));
            // You can also draw whatever you like on this!
            context.DrawLine(new Pen(Brushes.PeachPuff, 4.0), new Point(0, 0), new Point(100, 100));
            context.Close();

            var renderTarget = new RenderTargetBitmap((int)Src.Source.Width, (int)Src.Source.Height, 96, 96, PixelFormats.Pbgra32);
            renderTarget.Render(visual);

            Dst.Source = renderTarget;
        }
    }
}

在上面的示例中，图像呈现在顶部单击按钮时，图像 Src 将绘制到 Dst 图像上。由于 RenderContext 可用，您可以按照自己喜欢的方式操作图像。



希望这会有所帮助，

Fredrik

In the above example the image, as rendered onto the top image, Src, is draw onto the Dst image when the button is clicked. As the RenderContext is available you can manipulate the image any which way you like.

Hope this helps,
Fredrik

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