module1.bas

这里有很多很实用的VB编程案例,方便大家学习VB.

Attribute VB_Name = "Module1"
    Option Explicit

    Private Type Rect
          Left As Long
          Top As Long
          Right As Long
          Bottom As Long
    End Type

    Private Type CharRange
     cpMin As Long
     cpMax As Long
   End Type

   Private Type FormatRange
     hdc As Long
     hdcTarget As Long
     rc As Rect
     rcPage As Rect
     chrg As CharRange
   End Type
   
   Private Const WM_USER As Long = &H400
   Private Const EM_FORMATRANGE As Long = WM_USER + 57
   Private Const EM_SETTARGETDEVICE As Long = WM_USER + 72
   Private Const PHYSICALOFFSETX As Long = 112
   Private Const PHYSICALOFFSETY As Long = 113

   Private Declare Function GetDeviceCaps Lib "gdi32" (ByVal hdc As Long, ByVal nIndex As Long) As Long
   Private Declare Function SendMessage Lib "USER32" Alias "SendMessageA" (ByVal hWnd As Long, ByVal msg As Long, ByVal wp As Long, lp As Any) As Long
   Private Declare Function CreateDC Lib "gdi32" Alias "CreateDCA" (ByVal lpDriverName As String, ByVal lpDeviceName As String, ByVal lpOutput As Long, ByVal lpInitData As Long) As Long

         
          Public Function WYSIWYG_RTF(RTF As RichTextBox, LeftMarginWidth As Long, RightMarginWidth As Long) As Long
             Dim LeftOffset As Long, LeftMargin As Long, RightMargin As Long
             Dim LineWidth As Long
             Dim PrinterhDC As Long
             Dim r As Long
             ' 初始化。
             Printer.Print Space(1)
             Printer.ScaleMode = vbTwips

             LeftOffset = Printer.ScaleX(GetDeviceCaps(Printer.hdc, PHYSICALOFFSETX), vbPixels, vbTwips)

             LeftMargin = LeftMarginWidth - LeftOffset
             RightMargin = (Printer.Width - RightMarginWidth) - LeftOffset

             LineWidth = RightMargin - LeftMargin

             PrinterhDC = CreateDC(Printer.DriverName, Printer.DeviceName, 0, 0)

             r = SendMessage(RTF.hWnd, EM_SETTARGETDEVICE, PrinterhDC, ByVal LineWidth)

             Printer.KillDoc
             WYSIWYG_RTF = LineWidth
          End Function


    Public Sub PrintRTF(RTF As RichTextBox, LeftMarginWidth As Long, _
       TopMarginHeight, RightMarginWidth, BottomMarginHeight)
       Dim LeftOffset As Long, TopOffset As Long
       Dim LeftMargin As Long, TopMargin As Long
       Dim RightMargin As Long, BottomMargin As Long
       Dim fr As FormatRange
       Dim rcDrawTo As Rect
       Dim rcPage As Rect
       Dim TextLength As Long
       Dim NextCharPosition As Long
       Dim r As Long

       Printer.Print Space(1)
       Printer.ScaleMode = vbTwips

       LeftOffset = Printer.ScaleX(GetDeviceCaps(Printer.hdc, PHYSICALOFFSETX), vbPixels, vbTwips)
       TopOffset = Printer.ScaleY(GetDeviceCaps(Printer.hdc, PHYSICALOFFSETY), vbPixels, vbTwips)

       LeftMargin = LeftMarginWidth - LeftOffset
       TopMargin = TopMarginHeight - TopOffset
       RightMargin = (Printer.Width - RightMarginWidth) - LeftOffset
       BottomMargin = (Printer.Height - BottomMarginHeight) - TopOffset

       rcPage.Left = 0
       rcPage.Top = 0
       rcPage.Right = Printer.ScaleWidth
       rcPage.Bottom = Printer.ScaleHeight

       rcDrawTo.Left = LeftMargin
       rcDrawTo.Top = TopMargin
       rcDrawTo.Right = RightMargin
       rcDrawTo.Bottom = BottomMargin

       fr.hdc = Printer.hdc
       fr.hdcTarget = Printer.hdc
       fr.rc = rcDrawTo
       fr.rcPage = rcPage
       fr.chrg.cpMin = 0
       fr.chrg.cpMax = -1

       TextLength = Len(RTF.Text)

       Do
          NextCharPosition = SendMessage(RTF.hWnd, EM_FORMATRANGE, True, fr)
          If NextCharPosition >= TextLength Then Exit Do
          fr.chrg.cpMin = NextCharPosition
          Printer.NewPage
          Printer.Print Space(1)
          fr.hdc = Printer.hdc
          fr.hdcTarget = Printer.hdc
       Loop

       Printer.EndDoc

       r = SendMessage(RTF.hWnd, EM_FORMATRANGE, False, ByVal CLng(0))
    End Sub