如何在 WPF 中制作 UIElement 的截图 [英] How make a Screenshot of UIElement in WPF
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问题描述
我在创建 scatterview 的屏幕截图时遇到问题.我的屏幕截图总是包含一个黑框.
I have a problem with creating a screenshot of a scatterview. My screenshot always contains a black frame.
这是我的 XAML 代码:
Here's my XAML-Code:
<s:SurfaceWindow
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:s="http://schemas.microsoft.com/surface/2008"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" mc:Ignorable="d" x:Class="MakeScreenshots.SurfaceWindow1"
Title="MakeScreenshots" Width="1000" Height="700"
>
<s:SurfaceWindow.Resources>
<ImageBrush x:Key="WindowBackground" Stretch="None" Opacity="0.6" ImageSource="pack://application:,,,/Resources/WindowBackground.jpg"/>
</s:SurfaceWindow.Resources>
<Grid x:Name="GlobalGrid" Background="{StaticResource WindowBackground}" Width="1000" Height="700" >
<s:ScatterView x:Name="ScatterViewScreenShot" Margin="108,89,176,73" Width="700" Height="500">
<s:ScatterView.Background>
<SolidColorBrush Color="{DynamicResource {x:Static SystemColors.ActiveCaptionColorKey}}"/>
</s:ScatterView.Background>
<s:ScatterViewItem Margin="0,-26.953,-130.946,-23.047" Content="ScatterViewItem 3" HorizontalAlignment="Right" Width="125.826"/>
<s:ScatterViewItem Margin="0,0,-490.513,-151.256" HorizontalAlignment="Right" Width="125.77" Height="60.427" VerticalAlignment="Bottom" Content="ScatterViewItem 2"/>
<s:ScatterViewItem Content="ScatterViewItem 1" Margin="-331.43,0,0,-129.589" HorizontalAlignment="Left" Width="177.949" Height="67.905" VerticalAlignment="Bottom"/>
</s:ScatterView>
<Button x:Name="MakeScreenShotButton" Click="MakeScreenShotButton_Click" Content="MakeScreenShot" Margin="267,17,343,0" VerticalAlignment="Top" Height="38.96"/>
<Button Content="MakeScreenShotButton2" Height="39" HorizontalAlignment="Left" Margin="116,614,0,0" Name="button1" VerticalAlignment="Top" Width="301" Click="MakeScreenShotButton2_Click" />
<Button Content="MakeScreenShotButton3" Click="MakeScreenShotButton3_Click" Height="39" HorizontalAlignment="Left" Margin="822,207,0,0" Name="button2" VerticalAlignment="Top" Width="147" />
<Button Content="MakeScreenShotButton4" Click="MakeScreenShotButton4_Click" Height="39" HorizontalAlignment="Left" Margin="822,349,0,0" Name="button3" VerticalAlignment="Top" Width="147" />
<Button Content="MakeScreenShotButton5" Click="MakeScreenShotButton5_Click" Height="39" HorizontalAlignment="Left" Margin="822,443,0,0" Name="button4" VerticalAlignment="Top" Width="147" />
</Grid>
</s:SurfaceWindow>
这是c#代码:
private void MakeScreenShotButton_Click(object sender, RoutedEventArgs e)
{
RenderTargetBitmap targetBitmap = new RenderTargetBitmap((int)ScatterViewScreenShot.ActualWidth, (int)ScatterViewScreenShot.ActualHeight, 80d, 80d, PixelFormats.Default);
targetBitmap.Render(ScatterViewScreenShot);
// add the RenderTargetBitmap to a Bitmapencoder
JpegBitmapEncoder encoder = new JpegBitmapEncoder();
encoder.Frames.Add(BitmapFrame.Create(targetBitmap));
// Encoder zum Speichern des Bildes
JpegBitmapEncoder encoderToSave = new JpegBitmapEncoder();
encoderToSave.Frames.Add(BitmapFrame.Create(targetBitmap));
// Speichern des Bildes auf der Festplatte
string fileName = "M:\\TestForStackOverflow.jpg";
System.IO.FileStream fs = System.IO.File.Open(fileName, System.IO.FileMode.OpenOrCreate);
encoderToSave.Save(fs);
encoder.QualityLevel = 40;
MemoryStream ms = new MemoryStream();
encoder.Save(ms);
// Convert Image to byte[]
byte[] imageBytes = ms.ToArray();
int anzahlBytes = imageBytes.Length;
string imageAsBase64String = Convert.ToBase64String(imageBytes);
TCP_Client client = new TCP_Client("192.168.5.3", 4321);
client.sendeNachricht(imageAsBase64String);
}
private void MakeScreenShotButton2_Click(object sender, RoutedEventArgs e)
{
// 1. Bitmap der gewünschten Größe erstellen
int width = (int)ScatterViewScreenShot.ActualWidth;
int height = (int)ScatterViewScreenShot.ActualHeight;
RenderTargetBitmap rtb = new RenderTargetBitmap(width, height, 100d, 100d, PixelFormats.Default); // 500 x 500 genau wie bei den Produktfotos
// 2. Control in Bitmap hinein rendern
Visual vis = (Visual)ScatterViewScreenShot;
rtb.Render(vis);
// 3. Control-Image erzeugen und dem Control-Image als Source das Bitmap übergeben
System.Windows.Controls.Image img = new System.Windows.Controls.Image();
img.Source = rtb;
img.Stretch = Stretch.None;
// 4. Aktualisieren der Größe des Elements entsprechend des Inhaltes mittels der Methoden Measure und Arrange.
img.Measure(new System.Windows.Size(width, height));
System.Windows.Size sizeImage = img.DesiredSize;
img.Arrange(new System.Windows.Rect(new System.Windows.Point(0, 0), sizeImage));
// 5. Image wird mit der korrekten Größe erneut gerendert und an PngBitmapEncoder übergeben
RenderTargetBitmap rtb2 = new RenderTargetBitmap((int)rtb.Width, (int)rtb.Height, 60, 60, PixelFormats.Default);
rtb2.Render(img);
PngBitmapEncoder jpeg = new PngBitmapEncoder();
jpeg.Frames.Add(BitmapFrame.Create(rtb2));
// 6. Image in Stream schreiben
MemoryStream ms = new MemoryStream();
jpeg.Save(ms);
// Convert Image to byte[]
byte[] imageBytes = ms.ToArray();
int anzahlBytes = imageBytes.Length;
string imageAsBase64String = Convert.ToBase64String(imageBytes);
TCP_Client client = new TCP_Client("192.168.5.3", 4321);
client.sendeNachricht(imageAsBase64String);
}
private void MakeScreenShotButton3_Click(object sender, RoutedEventArgs e)
{
int width_x = 240;
int width_y = 400;
Bitmap screen = TakeScreenshot(100, 100, width_x, width_y);
System.Drawing.Image img = (System.Drawing.Image)screen;
//Image img = Image.FromFile("bla.jpg");
MemoryStream ms = new MemoryStream();
try
{
//Ein ImageCodecInfo-Objekt für den JPEG-Codec anlegen
ImageCodecInfo jpegCodec = null;
//Den Qualitätsarameter konfigurieren (Qualitätsfaktor in
//Prozent angeben)
EncoderParameter qualitaetsParameter = new EncoderParameter(
System.Drawing.Imaging.Encoder.Quality, 40);
//Alle im System verfügbaren Codecs auflisten
ImageCodecInfo[] alleCodecs = ImageCodecInfo.GetImageEncoders();
EncoderParameters codecParameter = new EncoderParameters(1);
codecParameter.Param[0] = qualitaetsParameter;
//Den JPEG-Codec unter allen Codecs finden und dem
//Codec-Info-Objekt zuweisen
for (int i = 0; i < alleCodecs.Length; i++)
{
if (alleCodecs[i].MimeType == "image/jpeg")
{
jpegCodec = alleCodecs[i];
break;
}
}
// Bild in Stream schreiben
img.Save(ms, jpegCodec, codecParameter);
}
catch (ArgumentException w)
{
throw w;
}
// Console.WriteLine(StreamToBase64(ms, System.Drawing.Imaging.ImageFormat.Jpeg));
String bildBase64 = StreamToBase64(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
TCP_Client client = new TCP_Client("192.168.5.3", 4321);
client.sendeNachricht(bildBase64);
}
private void MakeScreenShotButton4_Click(object sender, RoutedEventArgs e)
{
// save current canvas transform
Transform transform = ScatterViewScreenShot.LayoutTransform;
// get size of control
System.Windows.Size sizeOfControl = new System.Windows.Size(ScatterViewScreenShot.ActualWidth, ScatterViewScreenShot.ActualHeight);
// measure and arrange the control
ScatterViewScreenShot.Measure(sizeOfControl);
// arrange the surface
ScatterViewScreenShot.Arrange(new Rect(sizeOfControl));
// craete and render surface and push bitmap to it
RenderTargetBitmap renderBitmap = new RenderTargetBitmap((Int32)sizeOfControl.Width, (Int32)sizeOfControl.Height, 96d, 96d, PixelFormats.Pbgra32);
// now render surface to bitmap
renderBitmap.Render(ScatterViewScreenShot);
// encode png data
PngBitmapEncoder pngEncoder = new PngBitmapEncoder();
// puch rendered bitmap into it
pngEncoder.Frames.Add(BitmapFrame.Create(renderBitmap));
/* Speichern des Bildes auf der Festplatte
string fileName = "M:\\ScreenshotClick4.jpg";
System.IO.FileStream fs = System.IO.File.Open(fileName, System.IO.FileMode.OpenOrCreate);
pngEncoder.Save(fs);*/
// Encoder zum Senden des Bildes
JpegBitmapEncoder encoder = new JpegBitmapEncoder();
encoder.Frames.Add(BitmapFrame.Create(renderBitmap));
MemoryStream ms = new MemoryStream();
encoder.Save(ms);
// Convert Image to byte[]
byte[] imageBytes = ms.ToArray();
int anzahlBytes = imageBytes.Length;
string imageAsBase64String = Convert.ToBase64String(imageBytes);
TCP_Client client = new TCP_Client("192.168.5.3", 4321);
client.sendeNachricht(imageAsBase64String);
}
private void MakeScreenShotButton5_Click(object sender, RoutedEventArgs e)
{
int scale = 1;
double actualHeight = ScatterViewScreenShot.RenderSize.Height;
double actualWidth = ScatterViewScreenShot.RenderSize.Width;
double renderHeight = actualHeight * scale;
double renderWidth = actualWidth * scale;
RenderTargetBitmap renderTarget = new RenderTargetBitmap((int)renderWidth, (int)renderHeight, 96, 96, PixelFormats.Pbgra32);
VisualBrush sourceBrush = new VisualBrush(ScatterViewScreenShot);
DrawingVisual drawingVisual = new DrawingVisual();
DrawingContext drawingContext = drawingVisual.RenderOpen();
using (drawingContext)
{
drawingContext.PushTransform(new ScaleTransform(actualWidth, actualHeight));
drawingContext.DrawRectangle(sourceBrush, null, new Rect(new System.Windows.Point(0, 0), new System.Windows.Point(actualWidth, actualHeight)));
}
renderTarget.Render(drawingVisual);
JpegBitmapEncoder jpgEncoder = new JpegBitmapEncoder();
jpgEncoder.QualityLevel = 40;
jpgEncoder.Frames.Add(BitmapFrame.Create(renderTarget));
MemoryStream ms = new MemoryStream();
jpgEncoder.Save(ms);
// Convert Image to byte[]
byte[] imageBytes = ms.ToArray();
int anzahlBytes = imageBytes.Length;
string imageAsBase64String = Convert.ToBase64String(imageBytes);
TCP_Client client = new TCP_Client("192.168.5.3", 4321);
client.sendeNachricht(imageAsBase64String);
}
#region Hilfsmethoden
public string StreamToBase64(MemoryStream ms, System.Drawing.Imaging.ImageFormat format)
{
// Convert Image to byte[]
byte[] imageBytes = ms.ToArray();
// Convert byte[] to Base64 String
string base64String = Convert.ToBase64String(imageBytes);
return base64String;
}
private Bitmap TakeScreenshot(int StartX, int StartY, int Width, int Height)
{
Bitmap Screenshot = new Bitmap(Width, Height);
Graphics G = Graphics.FromImage(Screenshot);
G.CopyFromScreen(StartX, StartY, 0, 0, new System.Drawing.Size(Width, Height), CopyPixelOperation.SourceCopy);
return Screenshot;
}
#endregion
}
}
推荐答案
以下文章提供了解决您问题的方法:
the following article has a workaround for your problem:
拍摄 WPF 的截图"
Taking WPF "Screenshots"
http://www.grumpydev.com/2009/01/03/taking-wpf-截图/
///
/// Gets a JPG "screenshot" of the current UIElement
///
/// UIElement to screenshot
/// Scale to render the screenshot
/// JPG Quality
/// Byte array of JPG data
public static byte[] GetJpgImage(this UIElement source, double scale, int quality)
{
double actualHeight = source.RenderSize.Height;
double actualWidth = source.RenderSize.Width;
double renderHeight = actualHeight * scale;
double renderWidth = actualWidth * scale;
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(scale, scale));
drawingContext.DrawRectangle(sourceBrush, null, new Rect(new Point(0, 0), new Point(actualWidth, actualHeight)));
}
renderTarget.Render(drawingVisual);
JpegBitmapEncoder jpgEncoder = new JpegBitmapEncoder();
jpgEncoder.QualityLevel = quality;
jpgEncoder.Frames.Add(BitmapFrame.Create(renderTarget));
Byte[] _imageArray;
using (MemoryStream outputStream = new MemoryStream())
{
jpgEncoder.Save(outputStream);
_imageArray = outputStream.ToArray();
}
return _imageArray;
}
希望能帮到你
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