How To Set ActiveX Procedure and User Interface Defaults

MORE INFORMATION

The Visual Basic Help states that the User Interface Default (UI Default) "Determines which property is highlighted in the property browser ..." The following steps describe the behavior of Visual Basic for UI Default properties:

1. When a control is selected in design-mode, Visual Basic checks if the user has highlighted any property for the previously selected control. If the highlighted property is available for the selected control, that property will be highlighted. Otherwise, the property marked as UI Default will be highlighted.
2. When Visual Basic is started, the property window always highlights the "UI Default" property. As new controls are added, the "UI Default" property for each control will be highlighted unless the user explicitly selects some other property.

Step-by-Step Example

1. Start a new Visual Basic Standard EXE project. Form1 is created by default. Click on Form1. The property highlighted is "Caption," which is "UI Default" for Form.
2. Add a TextBox, Text1, to Form1. Now, the highlighted property is "Text," which is the "UI Default" for a TextBox.
3. Add a PictureBox to Form1. Now, the highlighted property is "Picture," and it is the "UI Default."
4. Click on the Form, TextBox, etc., and note that the UI Default is automatically highlighted.
5. Click on Text1. The "Text" property is highlighted. Click on the Name property to select it.
6. Click on other controls and note that the Name property is highlighted for all the controls.
7. Click on Text1 and select the "Alignment" property. Select other controls. If the previously selected property is available, that property will be highlighted. Otherwise, the UI Default property is highlighted.
   
   This is not intended to confuse, only to point out that the highlighted property in the properties window will vary depending on the state of the IDE, and a property defined as the UI Default will not always be highlighted.

Difference Between Default Procedure ID and User Interface Default

When you display the Procedure Attributes dialog and press the Advanced button, you will see a combo box titled "Procedure ID" and a check box with the description "User Interface Default." These fields serve two different purposes; the Procedure ID settings are for run-time and the User Interface Default is a design-time setting.

The Default setting for Procedure ID is available for Properties or Methods, but not for Events. You may have only one Procedure specified as "Default" per component. What a default Procedure ID setting means is that the default method or property will be executed when no specific member is specified. For example, the following statement on the client form will cause the default method of the UserControl (in this case a Subroutine) to execute:

   UserControl11
				

The following line of code will cause the default property of the control to be set to the string "This is my control," assuming the default property will accept one:

   UserControl11 = "This is my control"
				

The User Interface Default setting is available for Events or Properties, but not for Methods. You can have one UI Default property and one UI Default event per component. The purpose of the UI Default for a property is to determine which property is displayed in the properties window at design-time when the control is selected or placed on a form, subject to the behavior discussed earlier in this article. The purpose of the UI Default for an event is to specify which event procedure should appear when you double-click on the control. This applies to the control when it is seated on a form, not to the control itself.

NOTE: If you are changing User Interface Default properties and they don't seem to be taking effect, run the form and then go back into design mode and test again. The UI Defaults, particularly the event default that determines which event procedure is displayed when double-clicking, may not get refreshed until the form has been run.