希望修改以下内容以截取所有显示器的屏幕截图.我试过调整它但我的图像是空白的.将它写入test.png是为了测试. byte []将被发送到接收应用程序.
public byte[] Take()
{
int screenWidth = Convert.ToInt32(SystemParameters.VirtualScreenWidth);
int screenHeight = Convert.ToInt32(SystemParameters.VirtualScreenHeight);
int screenLeft = Convert.ToInt32(SystemParameters.VirtualScreenLeft);
int screenTop = Convert.ToInt32(SystemParameters.VirtualScreenTop);
RenderTargetBitmap renderTarget = new RenderTargetBitmap(screenWidth,screenHeight,96,PixelFormats.Pbgra32);
VisualBrush sourceBrush = new VisualBrush();
DrawingVisual drawingVisual = new DrawingVisual();
DrawingContext drawingContext = drawingVisual.RenderOpen();
using (drawingContext)
{
drawingContext.PushTransform(new ScaleTransform(1,1));
drawingContext.DrawRectangle(sourceBrush,null,new Rect(new Point(0,0),new Point(screenWidth,screenHeight)));
}
renderTarget.Render(drawingVisual);
PngBitmapEncoder pngEncoder = new PngBitmapEncoder();
pngEncoder.Frames.Add(BitmapFrame.Create(renderTarget));
Byte[] _imageArray;
using (MemoryStream outputStream = new MemoryStream())
{
pngEncoder.Save(outputStream);
_imageArray = outputStream.ToArray();
}
using (FileStream stream = new FileStream(@"c:\test.png",FileMode.Create,FileAccess.ReadWrite))
{
using (BinaryWriter writer = new BinaryWriter(stream))
{
writer.Write(_imageArray);
}
}
return _imageArray;
}
解决方法
首先,您需要为以下命名空间添加引用：
using System.Drawing; using System.Drawing.Imaging; using System.Windows.Forms;
然后枚举您的监视器以获取所有显示表面的边界矩形,并将其传递给Graphics.CopyFromScreen()方法调用：
private static BitmapSource CopyScreen()
{
var left = Screen.AllScreens.Min(screen => screen.Bounds.X);
var top = Screen.AllScreens.Min(screen => screen.Bounds.Y);
var right = Screen.AllScreens.Max(screen => screen.Bounds.X + screen.Bounds.Width);
var bottom = Screen.AllScreens.Max(screen => screen.Bounds.Y + screen.Bounds.Height);
var width = right - left;
var height = bottom - top;
using (var screenBmp = new Bitmap(width,height,System.Drawing.Imaging.PixelFormat.Format32bppArgb))
{
using (var bmpGraphics = Graphics.FromImage(screenBmp))
{
bmpGraphics.CopyFromScreen(left,top,new System.Drawing.Size(width,height));
return Imaging.CreateBitmapSourceFromHBitmap(
screenBmp.GetHbitmap(),IntPtr.Zero,Int32Rect.Empty,BitmapSizeOptions.FromEmptyOptions());
}
}
}
请记住,虽然显示器通常不能整齐地放入单个矩形中,特别是如果它们具有不同的分辨率等,因此您可能更好地快照单个屏幕.无论哪种方式,您的问题的解决方案是将您传入的坐标更改为Graphics.CopyFromScreen()方法调用.
编辑：请参阅下面的Demetris Leptos的评论,我在这个答案中发布的代码应该是在screenBmp.GetHbitmap()返回的位图上调用DeleteObject,以避免内存泄漏,如MSDN文档中所指定的.
