ダイアログマネージャーの自己終了方法のカスタマイズ: Close経路の分離

We started by exploring the signals the dialog manager uses for dismissing a dialog. Now we can use that information to customize the dismiss behavior.

Let’s start with a diagram, because people like diagrams.

WM_SYS­COMMAND/ SC_CLOSE

Close button/ Alt+F4/ System menu Close

User clicks Cancel button

WM_COMMAND/ BN_CLICK/ IDCANCEL

Is­Dialog­Message

We noted at the end of that article that if you have a button whose ID is IDCANCEL

Notice that everything in the diagram funnels into WM_COMMAND

Now, if you have no intention of closing the dialog in response to the Close button or the system menu Close command, then you probably shouldn’t leave them enabled. You can gray those out by doing

EnableMenuItem(GetSystemMenu(hDlg, FALSE), SC_CLOSE, MF_BYCOMMAND | MF_DISABLED | MF_GRAYED);

Okay, but what if you want to treat the Close button differently?

From the diagram, we see that the Close button goes through a WM_CLOSE

If you want to treat the ESC key differently from a click on the Cancel button, you’ll have to intercept it on the Is­Dialog­Message

¹ Now, you might notice that there is no requirement that the IDCANCEL