Q195087: HOWTO: Enable Communications Between UserDocuments/UserControls

Article: Q195087
Product(s): Microsoft Visual Basic for Windows
Version(s): WINDOWS:5.0,6.0
Operating System(s): 
Keyword(s): kbcode kbCtrl kbVBp kbVBp500 kbVBp600 kbGrpDSVBDB kbCodeSam
Last Modified: 24-JUL-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 covers how to enable communications between UserControls and
UserDocuments and other programs. There are times when both UserControls and
UserDocuments need to communicate with other forms that are part of the entire
program. Making public functions and public subroutines only enables
communications from parent forms and processes. Using GLOBAL instead of PUBLIC
allows information to be shared between controls, classes, and forms.

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

The project code below is an example of Global Variables being shared:

1. Create a Standard EXE project in Visual Basic. Form1 is created by default.

2. Select ActiveX Document EXE.

3. Add two additional UserDocuments and one module to the project. Cut and paste
  the following code into the module's code pane:

        Option Explicit

        Global MyNumber As Variant

4. For Document1, add two commandbuttons, a label. and one textbox. Place the
  label above the textbox and clear text1.Text. Cut and paste the following
  code into its code pane:

        Private Sub UserDocument_Initialize()
           Command2.Caption = ">>"
           Label1.Caption = "Set the number below"
        End Sub

        Private Sub Command1_Click()
           MyNumber = Text1.Text
        End Sub

        Private Sub Command2_Click()
           UserDocument.Hyperlink.NavigateTo App.Path & "\UserDocument2.Vbd"
        End Sub

5. For Document2, add two command buttons, a label and one textbox. Place the
  label above the textbox and clear text1.Text. Cut and paste the following
  code into its code pane:

        Private Sub Command1_Click()
           UserDocument.Hyperlink.GoBack
        End Sub

        Private Sub Command2_Click()
           UserDocument.Hyperlink.NavigateTo App.Path & "\UserDocument3.vbd"
        End Sub

        Private Sub UserDocument_Initialize()
           Command1.Caption = "<<"
           Command2.Caption = ">>"
           Label1.Caption = "The Magic Number Is"
            Text1.Text = MyNumber
        End Sub

6. For Document3, add two command buttons, a label and one textbox. Place the
  label above the textbox and clear text1.Text. Cut and paste the following
  code into its code pane:

        Private Sub Command1_Click()
          UserDocument.Hyperlink.GoBack
        End Sub

        Private Sub UserDocument_Initialize()
          Command1.Caption = "<<"
          Label1.Caption = "The Magic Number Is"
          Text1.Text = MyNumber
        End Sub

7. Run the project. Type a number in the text box and click the Command1 button.
  Next, navigate to the other two documents and notice your number shows up.
  Navigate back. When you navigate back to UserDocument1, the number you placed
  in the text will be gone. Also notice that no matter how many times you
  navigate back and forth between the documents, the number you added to the
  Global variable is always the same and always available.

REFERENCES
==========

For more information about UserControls and UserDocuments, use VB Help and query
UserControls or UserDocuments.

(c) Microsoft Corporation 1998, All Rights Reserved. Contributions by Richard T.
Edwards, Microsoft Corporation


Additional query words: kbDSupport Kbdse

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Keywords          : kbcode kbCtrl kbVBp kbVBp500 kbVBp600 kbGrpDSVBDB kbCodeSam 
Technology        : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2 kbVB500Search kbVB600Search kbVB500 kbVB600
Version           : WINDOWS:5.0,6.0
Issue type        : kbhowto

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