Windows Forms FAQ resources

15. Windows Forms Printing

15.1 How do I print a form?

I am afraid there is not a very easy way to print a form. You may implement this function with the steps below:

1. Add a print function to your application.

To do this, you should add a PrintDocument component to your application.

Please drag a PrintDocument from the tool box to your form. After that, you

should create a PrintDialog and add the code to print the document.

private void buttonPrint_Click(object sender, System.EventArgs e)

{

PrintDialog printDialog1 = new PrintDialog();

printDialog1.Document = printDocument1;

DialogResult result = printDialog1.ShowDialog();

if (result == DialogResult.OK)

{

printDocument1.Print();

}

For detailed information about print framework, please see "Windows Forms

Print Support" in the MSDN (October 2001).

2. Draw the form when printing.

This step is a little complex. You should handle the PrintPage of the

printDocument1 and draw the form to the printer device. In the event you

may copy the form to an image and then draw it to the printer device.

private void printDocument1_PrintPage(object sender,

System.Drawing.Printing.PrintPageEventArgs e)

{

Graphics graphic = this.CreateGraphics();

Size s = this.Size;

Image memImage = new Bitmap(s.Width, s.Height, graphic);

Graphics memGraphic = Graphics.FromImage(memImage);

IntPtr dc1 = graphic.GetHdc();

IntPtr dc2 = memGraphic.GetHdc();

BitBlt(dc2, 0, 0, this.ClientRectangle.Width,

this.ClientRectangle.Height, dc1, 0, 0, 13369376);

graphic.ReleaseHdc(dc1);

memGraphic.ReleaseHdc(dc2);

e.Graphics.DrawImage(memImage,0,0);

}

The above referenced the article "Screen Capturing a Form in .NET - Using

GDI in GDI+" by Michael Gold. You may find it at:

http://www.c-sharpcorner.com/Graphics/ScreenCaptFormMG.asp

3. Declare the API function.

Please note the BitBlt function used in Step 2. It is an unmanaged

function. You should use DllImportAttribute attribute to import it to your

code. Although, this is the Step 3, you may perform this step any time.

[System.Runtime.InteropServices.DllImportAttribute("gdi32.dll")]

private static extern bool BitBlt(

IntPtr hdcDest, // handle to destination DC

int nXDest, // x-coord of destination upper-left corner

int nYDest, // y-coord of destination upper-left corner

int nWidth, // width of destination rectangle

int nHeight, // height of destination rectangle

IntPtr hdcSrc, // handle to source DC

int nXSrc, // x-coordinate of source upper-left corner

int nYSrc, // y-coordinate of source upper-left corner

System.Int32 dwRop // raster operation code

);

For more information about DllImportAttribute attribute please see:

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpref/html/

frlrfSystemRuntimeInteropServicesDllImportAttributeClassTopic.asp

(from Lion Shi (lion_noreply@microsoft.com) on microsoft.public.dotnet.framework.windowsforms)