将 WPF InkCanvas 保存为 JPG - 图像被裁剪

Question

我有一个 WPF InkCanvas 控件，用于捕获应用程序中的签名。 该控件看起来像这样 - 700x300

但是，当我将其另存为 JPG 时，生成的图像看起来像这样，也是 700x300

我用来保存的代码

            sigPath = System.IO.Path.GetTempFileName();

            MemoryStream ms = new MemoryStream();
            FileStream fs = new FileStream(sigPath, FileMode.Create);

            RenderTargetBitmap rtb = new RenderTargetBitmap((int)inkSig.Width, (int)inkSig.Height, 96d, 96d, PixelFormats.Default);
            rtb.Render(inkSig);
            JpegBitmapEncoder encoder = new JpegBitmapEncoder();
            encoder.Frames.Add(BitmapFrame.Create(rtb));

            encoder.Save(fs);
            fs.Close();

这是我正在使用的 XAML：

<Window x:Class="Consent.Client.SigPanel"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Background="Transparent" Topmost="True" AllowsTransparency="True"
Title="SigPanel" Left="0" Top="0" Height="1024" Width="768" WindowStyle ="None" ShowInTaskbar="False" ResizeMode="NoResize" WindowStartupLocation="CenterScreen" >

<Border BorderThickness="1" BorderBrush="Black" Background='#FFFFFFFF' x:Name='DocumentRoot' Width='750' Height='400' CornerRadius='10'>
    <StackPanel HorizontalAlignment="Center" VerticalAlignment="Center">
        <TextBlock Name="txtLabel" FontSize="24" HorizontalAlignment="Center" >Label</TextBlock>
        <InkCanvas Opacity="1" Background="Beige" Name="inkSig" Width="700" Height="300" />

        <StackPanel HorizontalAlignment="Center" Orientation="Horizontal">
            <Button FontSize="24" Margin="10" Width="150" Name="btnSave" Click="btnSave_Click">Save</Button>
            <Button FontSize="24" Margin="10" Width="150" Name="btnCancel" Click="btnCancel_Click">Cancel</Button>
            <Button FontSize="24" Margin="10" Width="150" Name="btnClear" Click="btnClear_Click">Clear</Button>
        </StackPanel>
    </StackPanel>
</Border>

在过去，这非常有效。 我无法弄清楚是什么变化导致图像在保存时发生变化。

Answer 1

  var size = new Size(inkCanvas.ActualWidth, inkCanvas.ActualHeight);
    inkCanvas.Margin = new Thickness(0, 0, 0, 0);

    inkCanvas.Measure(size);
    inkCanvas.Arrange(new Rect(size));
    var encoder = new PngBitmapEncoder();
    var bitmapTarget = new RenderTargetBitmap((int)size.Width, (int)size.Height, 96, 96, PixelFormats.Default);
    bitmapTarget.Render(inkCanvas);
    encoder.Frames.Add(BitmapFrame.Create(bitmapTarget));
    encoder.Save(ms); 

Answer 2

我也遇到了同样的问题，我这样做了..它在这里工作..

    private void Button_Click(object sender, RoutedEventArgs e)
    {           
        double width = inkSig.ActualWidth;
        double height = inkSig.ActualHeight;
        RenderTargetBitmap bmpCopied = new RenderTargetBitmap((int)Math.Round(width), (int)Math.Round(height), 96, 96, PixelFormats.Default);
        DrawingVisual dv = new DrawingVisual();
        using (DrawingContext dc = dv.RenderOpen())
        {
            VisualBrush vb = new VisualBrush(inkSig);
            dc.DrawRectangle(vb, null, new Rect(new System.Windows.Point(), new System.Windows.Size(width, height)));
        }
        bmpCopied.Render(dv);
        System.Drawing.Bitmap bitmap;
        using (MemoryStream outStream = new MemoryStream())
        {
            // from System.Media.BitmapImage to System.Drawing.Bitmap 
            BitmapEncoder enc = new BmpBitmapEncoder();
            enc.Frames.Add(BitmapFrame.Create(bmpCopied));
            enc.Save(outStream);
            bitmap = new System.Drawing.Bitmap(outStream);
        }

        EncoderParameter qualityParam =
     new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, 85L);

        // Jpeg image codec
        ImageCodecInfo jpegCodec = getEncoderInfo("image/jpeg");

        if (jpegCodec == null)
            return;

        EncoderParameters encoderParams = new EncoderParameters(1);
        encoderParams.Param[0] = qualityParam;
        Bitmap btm = new Bitmap(bitmap);
        bitmap.Dispose();
        btm.Save("C:\\Users\\Pd\\Desktop\\dfe12.jpg", jpegCodec, encoderParams);
        btm.Dispose(); 
    }

    private ImageCodecInfo getEncoderInfo(string mimeType)
    {
        // Get image codecs for all image formats
        ImageCodecInfo[] codecs = ImageCodecInfo.GetImageEncoders();

        // Find the correct image codec
        for (int i = 0; i < codecs.Length; i++)
            if (codecs[i].MimeType == mimeType)
                return codecs[i];
        return null;
    } 

Answer 3

和
surface.Margin = new Thickness(55,40,96,5);
http://img519.imageshack.us/img519/7499/mynewimage.png

Answer 4

我的班级保存图像

     using System;
     using System.IO;
     using System.Windows;
     using System.Windows.Controls;
     using System.Windows.Media;
     using System.Windows.Media.Imaging;

     public void ExportToJpeg(String path,  InkCanvas surface)
    {
        double
                x1 = surface.Margin.Left,
                x2 = surface.Margin.Top,
                x3 = surface.Margin.Right,
                x4 = surface.Margin.Bottom;

        if (path == null) return;

        surface.Margin = new Thickness(0, 0, 0, 0);

      Size size = new Size(surface.Width, surface.Height);
   surface.Measure(size);
   surface.Arrange(new Rect(size));

         RenderTargetBitmap renderBitmap =
          new RenderTargetBitmap(
            (int)size.Width,
            (int)size.Height,
            96,
            96,
            PixelFormats.Default);
      renderBitmap.Render(surface);
      using (FileStream fs = File.Open(path, FileMode.Create))
        {
         JpegBitmapEncoder encoder = new JpegBitmapEncoder();
            encoder.Frames.Add(BitmapFrame.Create(renderBitmap));
            encoder.Save(fs);
        }
      surface.Margin = new Thickness(x1, x2, x3, x4);
    }

Answer 5

啊哈！ 问题在于位于 InkCanvas 正上方的 TextBlock txtLabel。 当你删除它时，黑线就会消失。

至于为什么会发生这种情况，我还不完全确定。

Answer 6

杰森，我解决了这个问题。
对不起我的英语。 我是俄罗斯人。
您需要在 0,0,0,0 设置属性 inkCanvas.Margin
with：

surface.Margin = new Thickness(0, 0, 0, 0);

在您的仓位保存设置保证金后。

例子：
http://img189.imageshack.us/img189/7499/mynewimage.png

Answer 7

我一直在网上寻找这个问题的答案，并尝试了大多数意见，但没有任何乐趣。 然后我尝试了这个并且成功了！

<Canvas x:Name="editCanvas" Background="Transparent" ClipToBounds="True">
        <InkCanvas EditingMode="Select" x:Name="inkCanvas"  Background="Transparent" Height="562" Width="866">

        </InkCanvas>
</Canvas>