Put simply, dynamic dialog control is all about the DialogFunc. A DialogFunc is a special type of function that is associated with the dialog GUI by entering a name in the field, like this:
NOTE: To get to this dialog, you can do one of two things:
By setting the "Dialog Function" field to "DialogFunc", we are making the required link between the GUI and the event handlers. When you apply the changes from the dialog editor to the code, you will get a prompt:
We recommend you always say "Yes". What happens when you say "Yes" is that a VB function is added at the end of your code, and it is populated in a very specific way. VERY IMPORTANT: A Dialog Function MUST take the form that is generated automatically as skeleton code. The individual cases in the
Select Case block are predefined and can not be changed. We can, however, add event handlers within this framework and create many types of actions by our dialogs.
If you run this code, you will see the following dialog:
All we have done so far is to place the controls, but we have not yet specified any behavior for the dialog. To do that, we will edit the DialogFunc to change how the dialog looks based on certain events.
Run the script and look at the text label for item 2. It should be disabled, as shown below:
DlgEnable statement was set to operate on the Text control whose
Field parameter is "Text2", and the enable status is set to
False, or not enabled.
When you run this modification, you will see that the text box that corresponds to the disabled label is now invisible (not just disabled):
Finally, lets look at how we can change the string displayed by a text label. In the upper right corner of the dialog, up to now you have seen "MsgOut", which is the default label specified in the dialog definition (
Text 280,14,210,14,"MsgOut",.msgOut). Again, there is a specific command to perform this task dynamically. Add the following line of code, again in the
Case 1 code block:
Run the code and you will see that the message in the upper right now matches the default selection of "1":
Wrapping Up Initialization
...and the dialog should appear like this:
Case 2: Value Changing or Button Pressed
These code changes should produce the following 4 states (betond the initialization state, which we have already discussed) if your dialog is operating properly:
Case 3: TextBox or ComboBox Changing
When you run this, select either "1" or "2" for the drop-down control, then enter an alphanumeric string in TextBox1. If, after making these changes, you shift the focus away from TextBox1 (but don't click the OK button yet), you will get a VB message box telling you which TextBox has changed and the number of characters in the new string. Note that the number of characters is reported by
SuppValue& in this case.
Since a ComboBox also lets the user enter text, it works in exactly the same way. It triggers the event when it loses focus after a text change, and the number of characters in the new string is reported by
When this code is executed and one of the above actions takes place, a MessageBox is displayed indicating which controls gained and lost focus. An example MessageBox is shown:
Complete Code Listing