HOWTO: Use the DrawText API Call from Visual Basic

• Standard, Professional, and Enterprise Editions of Microsoft Visual Basic, 32-bit only, for Windows, version 4.0

SUMMARY

The DrawText API gives users the ability to write text to a Device context giving various alignment and word-wrapping features. This article provides a code sample showing how to achieve these effects under the 32-bit Edition of Visual Basic 4.0.

MORE INFORMATION

1. Start a new project in Visual Basic. Form1 is created by default.

2. Add a Command button to Form1.

3. Place the following code in the General Declarations section of Form1:

         Option Explicit
   

         Private Declare Function DrawText Lib "user32" Alias "DrawTextA" _
           (ByVal hdc As Long, ByVal lpStr As String, ByVal nCount As Long, _
           lpRect As RECT, ByVal wFormat As Long) As Long
   
         Private Const DT_BOTTOM = &H8
         Private Const DT_CENTER = &H1
         Private Const DT_LEFT = &H0
         Private Const DT_RIGHT = &H2
         Private Const DT_TOP = &H0
         Private Const DT_VCENTER = &H4
         Private Const DT_WORDBREAK = &H10
   
         Private Type RECT
            Left As Long
            Top As Long
            Right As Long
            Bottom As Long
         End Type
   
         Private Sub Command1_Click()
           Dim lSuccess As Long
           Dim sPrintText As String
           Dim MyRect As RECT
           Form1.Font.Size = 12
           Form1.ScaleMode = vbPixels
           MyRect.Left = 0
           MyRect.Right = Form1.ScaleWidth
           MyRect.Top = 20
           MyRect.Bottom = 60
           sPrintText = "Print this text"
           lSuccess = DrawText(Form1.hdc, sPrintText, Len(sPrintText), _
           MyRect, DT_CENTER or DT_WORDBREAK)
         End Sub
   
   

4. Press the F5 key to run the project, and press the Command button. Text should appear in the middle of the form and be word-wrapped. If you Resize the form and run the project again, you will note that the text still appears in the middle of the form on the horizontal axis.

   Global Const DT_TOP = &H00000000
   Global Const DT_LEFT = &H00000000
   Global Const DT_CENTER = &H00000001
   Global Const DT_RIGHT = &H00000002
   Global Const DT_VCENTER = &H00000004
   Global Const DT_BOTTOM = &H00000008
   Global Const DT_WORDBREAK = &H00000010
   Global Const DT_SINGLELINE = &H00000020
   Global Const DT_EXPANDTABS = &H00000040
   Global Const DT_TABSTOP = &H00000080
   Global Const DT_NOCLIP = &H00000100
   Global Const DT_EXTERNALLEADING = &H00000200
   Global Const DT_CALCRECT = &H00000400
   Global Const DT_NOPREFIX = &H00000800
   Global Const DT_INTERNAL = &H00001000
   Global Const DT_EDITCONTROL = &H00002000
   Global Const DT_PATH_ELLIPSIS = &H00004000
   Global Const DT_END_ELLIPSIS = &H00008000
   Global Const DT_MODIFYSTRING = &H00010000
   Global Const DT_RTLREADING = &H00020000
   Global Const DT_WORD_ELLIPSIS = &H00040000

REFERENCES

The Win32 SDK has a comprehensive summary of Drawtext and other Drawing and Text functions.

Keywords          : vb432 VB4WIN vbwin GnrlVb kbprg
Technology        : kbvba
Version           : WINDOWS:4.0
Platform          : NT WINDOWS
Issue type        : kbhowto