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Q193540: HOWTO: Read and Display UNICODE String on Visual Basic Form

Article: Q193540
Product(s): Microsoft Visual Basic for Windows
Version(s): 5.0,6.0
Operating System(s): 
Keyword(s): kbCtrl kbUnicode kbVBp kbVBp500 kbVBp600 kbGrpDSO kbDSupport
Last Modified: 24-AUG-2001

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The information in this article applies to:

- Microsoft Visual Basic Professional Edition for Windows, versions 5.0, 6.0 
- Microsoft Visual Basic Enterprise Edition for Windows, versions 5.0, 6.0 
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SUMMARY
=======

This article demonstrates how to read a Unicode string from a Unicode text file
and display the string on a Visual Basic form.

MORE INFORMATION
================

Visual Basic is based internally on the double-byte Unicode standard. However,
most of the world outside of Visual Basic still uses the single- byte ANSI
model. For this reason, Visual Basic provides two sets of form controls and uses
the ANSI set as the default control. Any strings passed to the ANSI set of form
controls will be converted from their internal Unicode representation to an ANSI
representation and will not display the UNICODE strings correctly. To be able to
display the UNICODE string on a Visual Basic form, the UNICODE (Forms 2.0)
controls must be used. The following example shows how to use the Forms 2.0
controls to display UNICODE strings read from a Unicode text file. Because this
behavior requires UNICODE language package support, it currently supported only
in Windows NT.

NOTE: The Forms 2.0 controls used in this article were not designed for use on
Visual Basic forms and have not been formally tested in the environment. This
article documents their use only in this very limited context to work around a
limitation to the Visual Basic Intrinsic controls. Using other features of these
controls on Visual Basic forms is not supported.

Furthermore, Forms 2.0 is part of Microsoft Office and is not redistributable.
Therefore, you cannot distribute Forms 2.0 (fm20.dll) with your application. It
must already be on the target machines.

For additional information on distributing fm20.dll, please see the following
article in the Microsoft Knowledge Base:

  Q224305 INFO: Usage and Redistribution of FM20.DLL [OffDev]

Step-by-Step Guide to Build Sample
----------------------------------

1. Install the Chinese language package on your Windows NT computer. See the
  REFERENCES section below for installation instructions. The MingLiu font will
  be installed automatically during this step. You can also install other
  language packages if you want to use other UNICODE language support.

2. Create a standard EXE project. Form1 is created by default.

3. Select Components from the Project menu and check Microsoft Forms 2.0 Object
  Library. Several new controls are added to the toolbox, including UNICODE
  versions of the text box, label, and so forth.

4. Add a Forms 2.0 TextBox to Form1 and keep its default name: TextBox1. Set the
  font of the text box to be MingLiu.

5. Add two CommandButtons to Form1.

6. Add the following code to the code window of Form1:

        Private Sub Command1_Click()
          ' create a Unicode text file with Chinese character
          ' Dan1 and English character D.
          Dim a(0 To 5) As Byte
          a(0) = &HFF
          a(1) = &HFE
          a(2) = &H39
          a(3) = &H4E
          a(4) = &H44
          a(5) = &H0
          Open "unicode.txt" For Binary As #1
          Put #1, , a
          Close #1
        End Sub

        Private Sub Command2_Click()
          Dim txtline As String

          ' you may need to change the path of the file
          Open "unicode.txt" For Binary As #1

          txtline = InputB(2, #1)  ' always FF FE, skip them
          txtline = InputB(4, #1)

          Close #1

          TextBox1.Text = txtline  ' display the string
        End Sub

  Note that the UNICODE text file always begins with the Bytes FF FE, which is
  why you need to skip these two bytes. Also note that to read UNICODE strings
  from a file, the file needs to be opened as binary and read using InputB.

7. Run the application. Click Command1 to create the Unicode text file.

8. Click Command2. The Chinese character Dan1 and the English character D are
  displayed correctly in the text box. You can also check the unicode.txt file
  by using notepad with MingLiu font.

REFERENCES
==========

For additional information, please see the following articles in the Microsoft
Knowledge Base:

  Q177561 HOWTO: Add and Enable Additional Languages in Windows NT

  Q224305 INFO: Usage and Redistribution of FM20.DLL [OffDev]


Additional query words:

======================================================================
Keywords          : kbCtrl kbUnicode kbVBp kbVBp500 kbVBp600 kbGrpDSO kbDSupport 
Technology        : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2 kbVB500Search kbVB600Search kbVB500 kbVB600
Version           : :5.0,6.0
Issue type        : kbhowto

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