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VCL Components
for buttons that are used as regular buttons on the form and that do not close the form. If you
use any nonzero value for ModalResult, pressing the button will close the form and return the
ModalResult value. For example, if you place a button on a form and set the ModalResult
property to mrOk, pressing the button will close the form, and the return value from
ShowModal() will be mrOk (1). Given that, then, you can do something like the following:
int result = MyForm->ShowModal();
if (result == mrOK) DoSomething();
if (result == mrCancel) return;
Table 8.7 lists the ModalResult constants that VCL defines.
Table 8.7. VCL ModalResult constants.
Constant Value
NOTE
mrNone 0
mrOk 1
mrCancel 2
mrAbort 3
mrRetry 4
mrIgnore 5
mrYes 6
mrNo 7
mrAll 8
You don’t have to use one of the predefined ModalResult constants for
your buttons. You can use any value you like. Let’s say, for example,
you had a custom dialog box that could be closed by using a variety of
buttons. You could assign a different ModalResult value to each button
(100, 150, and 200, for example), and you would then know which
button closed the dialog box. Any nonzero number is valid, up to the
maximum value of an int.
You can get a program called ButtnTst from http://www.mcp.com/sams/codecenter.html; it
demonstrates the use of ModalResult. The program allows you to execute a form containing
several buttons. When you click a button, the ModalResult will be reported back on the main
form.
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