Visual Basic 6.0 offers a new option for projects:
"Remove information about unused ActiveX Controls."
This article discusses how to use this option.
The Make tab under the Project Properties menu has the following option:
"Remove information about unused ActiveX Controls"
If this option is selected, any ActiveX controls that have been referenced
but not sited within the project will not have their license information
included in the final compiled executable.
Visual Basic allows ActiveX controls to be dynamically loaded at run-time.
This feature raises concerns about being able to load/use controls which a
program legally should not be able to use.
Visual Basic has two ways of using an ActiveX control legally:
- Include the ActiveX control license within the compiled executable.
- Load the license for an ActiveX control during run-time before loading
the actual control.
Both ways ensure that the license for the control is checked (either during
development or during run-time) prior to the control being used.
A license that is included in a compiled executable will be part of the
Licenses collection object.
In order to add controls dynamically without concern about the License
collection object, make sure that the "Remove information about unused
ActiveX Controls" option is deselected.
Adding an ActiveX Control During Run-time That Requires a License
The following sample shows how to reference a control in Visual Basic and
add it dynamically during run-time without having to use the Licenses
- Create a new Standard EXE project in Visual Basic. Form1 is created by
- Select Components from the Project menu and select "Microsoft
Hierarchical FlexGrid Control 6.0 (OLEDB)."
- Add a CommandButton (Command1) to Form1.
- Add the following code to Form1:
Private Sub Command1_Click()
Dim ctlTest As VBControlExtender
' add a control dynamically to this form
Set ctlTest = Form1.Controls.Add _
' position and show the form
ctlTest.Move 100, (Command1.Top + Command1.Height) + 100
ctlTest.Visible = True
Private Sub Form_Load()
' move the command1 button to the corner for appearance.
Command1.Move 100, 100
- Compile the Project (Project1.Exe).
- Run the compiled Project.
- Click the "Command1" button. The following error will appear:
Although "Microsoft Hierarchical Flexgrid Control 6.0 (OLEDB)" is
referenced within the project, the License information for the controls
were removed because none of the controls were sited on any forms.
Running within the IDE would result in run-time error "50153."
Run-time Error "731"
"In order to use "MSHierarchicalFlexGridLib.MSHFlexgrid", you must
specify a license string for the control. Use Licenses.Add to add
the license string to the Licenses collection."
- In the design environment, select Project1 Properties from the
Project menu, then the "Make" tab on the Project1 Properties dialog.
- Make sure that the "remove information about unused ActiveX controls"
option is not selected.
- Make the project again.
- Run the compiled project.
- Click the "Command1" button. This time the Hierarchical Flexgrid
Control will be instantiated and will be sited on the form.
For additional information about the Licenses Collection Object, please see
the following article in the Microsoft Knowledge Base:
: HOWTO: What Is the Licenses Collection Used For?
Article ID: 190153 - Last Review: February 21, 2014 - Revision: 3.0
- Microsoft Visual Basic 6.0 Learning Edition
- Microsoft Visual Basic 6.0 Professional Edition
- Microsoft Visual Basic 6.0 Enterprise Edition
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