HOWTO: Enable Communications Between UserDocuments/ UserControls

• Microsoft Visual Basic Professional and Enterprise Editions for Windows, versions 5.0, 6.0

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

Keywords          : kbCtrl kbVBp kbVBp500 kbVBp600 kbCodeSam 
Version           : WINDOWS:5.0,6.0
Platform          : WINDOWS 
Issue type        : kbhowto 

Last Reviewed: June 18, 1999