VB.NET读写文本文件方法

示例

Private Declare Function BitBlt Lib "gdi32.dll" Alias "BitBlt" (ByVal _
   hdcDest As IntPtr, ByVal nXDest As Integer, ByVal nYDest As _
   Integer, ByVal nWidth As Integer, ByVal nHeight As Integer, ByVal _
   hdcSrc As IntPtr, ByVal nXSrc As Integer, ByVal nYSrc As Integer, _
   ByVal dwRop As System.Int32) As Long
Dim memoryImage As Bitmap
Private Sub CaptureScreen()
   Dim mygraphics As Graphics = Me.CreateGraphics()
   Dim s As Size = Me.Size
   memoryImage = New Bitmap(s.Width, s.Height, mygraphics)
   Dim memoryGraphics As Graphics = Graphics.FromImage(memoryImage)
   Dim dc1 As IntPtr = mygraphics.GetHdc
   Dim dc2 As IntPtr = memoryGraphics.GetHdc
   BitBlt(dc2, 0, 0, Me.ClientRectangle.Width, _
      Me.ClientRectangle.Height, dc1, 0, 0, 13369376)
   mygraphics.ReleaseHdc(dc1)
   memoryGraphics.ReleaseHdc(dc2)
End Sub
Private Sub PrintDocument1_PrintPage(ByVal sender As System.Object, _
   ByVal e As System.Drawing.Printing.PrintPageEventArgs) Handles _
   PrintDocument1.PrintPage
   e.Graphics.DrawImage(memoryImage, 0, 0)
End Sub
Private Sub PrintButton_Click(ByVal sender As System.Object, ByVal e As _
   System.EventArgs) Handles PrintButton.Click
   CaptureScreen()
   PrintDocument1.Print()
End Sub

编译代码
此示例需要：

窗体上名为 PrintDocument1 的 PrintDocument 组vb.net教程件。
名为 PrintButton 的 Button 控件。在单击 PrintButton 时，就会打印该窗体。