如何保存一个WPF ScrollViewer中的所有内容作为图像 [英] How do I save all content of a WPF ScrollViewer as an image

问题描述

我有包含垂直延伸的许多子控件ScrollViewer控件WPF窗口。当用户点击位于所述的ScrollViewer底部的按钮，我想的所有内容（视图中当前和选自视图）要保存为图像。

I have a WPF window with a ScrollViewer control containing many child controls that extend vertically. When a user clicks a button located at the bottom of the ScrollViewer I would like all the content (currently in view and out of view) to be saved as an image.

我使用下面的代码，我已经适应从示例来说明如何保存窗口的内容：

I am using the following code which I have adapted from examples showing how to save the content of a Window:

public static void SaveForm(ScrollViewer container, string filename)
{        
    const int dpi = 96;
    var rtb = new RenderTargetBitmap(
        (int)container.ExtentWidth, //width 
        (int)container.ExtentHeight, //height 
        dpi, //dpi x 
        dpi, //dpi y 
        PixelFormats.Pbgra32 // pixelformat 
        );

    rtb.Render(container);
    SaveRTBAsPNG(rtb, filename);
}

private static void SaveRTBAsPNG(RenderTargetBitmap bmp, string filename)
{
    var enc = new System.Windows.Media.Imaging.PngBitmapEncoder();
    enc.Frames.Add(System.Windows.Media.Imaging.BitmapFrame.Create(bmp));

    using (var stm = System.IO.File.Create(filename))
    {
        enc.Save(stm);
    }
}

目前一个PNG正在生产，但只具有该ScrollViewer中的当前可见的部分。有没有什么办法可以让PNG包含的所有内容，包括它需要被滚动到视图？

Currently a PNG is being produced but it only has the currently visible portion of the ScrollViewer. Is there any way I can get the PNG to contain all of the content, including that which needs to be scrolled into view?

推荐答案

使用此与内容您的ScrollViewer源，而不是你的ScrollViewer本身：
（这需要即使内容是不可见的快照）

Use this with the CONTENT of you scrollviewer as source, not your scrollviewer itself : (It takes a snapshot even if the content is not visible)

    public static void SnapShotPNG(this UIElement source, Uri destination, int zoom)
    {
        try
        {
            double actualHeight = source.RenderSize.Height;
            double actualWidth = source.RenderSize.Width;

            double renderHeight = actualHeight * zoom;
            double renderWidth = actualWidth * zoom;

            RenderTargetBitmap renderTarget = new RenderTargetBitmap((int)renderWidth, (int)renderHeight, 96, 96, PixelFormats.Pbgra32);
            VisualBrush sourceBrush = new VisualBrush(source);

            DrawingVisual drawingVisual = new DrawingVisual();
            DrawingContext drawingContext = drawingVisual.RenderOpen();

            using (drawingContext)
            {
                drawingContext.PushTransform(new ScaleTransform(zoom, zoom));
                drawingContext.DrawRectangle(sourceBrush, null, new Rect(new Point(0, 0), new Point(actualWidth, actualHeight)));
            }
            renderTarget.Render(drawingVisual);

            PngBitmapEncoder encoder = new PngBitmapEncoder();
            encoder.Frames.Add(BitmapFrame.Create(renderTarget));
            using (FileStream stream = new FileStream(destination.LocalPath, FileMode.Create, FileAccess.Write))
            {
                encoder.Save(stream);
            }
        }
        catch (Exception e)
        {
            MessageBox.Show(e);
        }
    }

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