在Windows应用程序中打印表格

Question

我试图获得一个按钮来打印出我当前的表单，并尝试了所有我可以在这里找到的代码，但它仍然打印空白页，我无法解决原因。

我使用的代码如下

Bitmap bitmap; 
private void btnPrint_Click(object sender, EventArgs e) 
{ 
//Add a Panel control. 
Panel panel = new Panel(); 
this.Controls.Add(panel); 

//Create a Bitmap of size same as that of the Form. 
Graphics grp = panel.CreateGraphics(); 
Size formSize = this.ClientSize; 
bitmap = new Bitmap(formSize.Width, formSize.Height, grp); 
grp = Graphics.FromImage(bitmap); 

//Copy screen area that that the Panel covers. 
Point panelLocation = PointToScreen(panel.Location); 
grp.CopyFromScreen(panelLocation.X, panelLocation.Y, 0, 0, formSize); 

//Show the Print Preview Dialog. 
printPreviewDialog1.Document = printDocument1; 
printPreviewDialog1.PrintPreviewControl.Zoom = 1; 
printPreviewDialog1.ShowDialog(); 
} 

private void PrintPage(object sender, System.Drawing.Printing.PrintPageEventArgs e) 
{ 
//Print the contents. 
e.Graphics.DrawImage(bitmap, 0, 0); 
} 

这从按钮（btnPrint），它是一个窗体（Form 2）上运行，以文本框的负荷和图形）

沿着当点击它带来打印预览对话框正常，但页面为空白。如果我按打印它打印一个空白页。

任何想法为什么它不复制的形式？

Answer 1

请参考：How to: Print Preview a Form

[System.Runtime.InteropServices.DllImport("gdi32.dll")] 
public static extern long BitBlt (IntPtr hdcDest, 
int nXDest, int nYDest, int nWidth, int nHeight, 
IntPtr hdcSrc, int nXSrc, int nYSrc, int dwRop); 
private Bitmap memoryImage; 
private void CaptureScreen() 
{ 
    Graphics mygraphics = this.CreateGraphics(); 
    Size s = this.Size; 
    memoryImage = new Bitmap(s.Width, s.Height, 
    mygraphics); 
    Graphics memoryGraphics = Graphics.FromImage(
    memoryImage); 
    IntPtr dc1 = mygraphics.GetHdc(); 
    IntPtr dc2 = memoryGraphics.GetHdc(); 
    BitBlt(dc2, 0, 0, this.ClientRectangle.Width, 
    this.ClientRectangle.Height, dc1, 0, 0, 
    13369376); 
    mygraphics.ReleaseHdc(dc1); 
    memoryGraphics.ReleaseHdc(dc2); 
} 

private void printDocument1_PrintPage(System.Object 
sender, System.Drawing.Printing.PrintPageEventArgs e) 
{ 
    e.Graphics.DrawImage(memoryImage, 0, 0); 
} 

private void printButton_Click(System.Object sender, 
System.EventArgs e) 
{ 
    CaptureScreen(); 
    printPreviewDialog1.Document = printDocument1; 
    printPreviewDialog1.Show(); 
}