Question

I want to notify the user that my application wants to start an elevated process using the standard MessageBox. Is there a way of achieving this short of reimplementing the MessageBox?

For example, for standard buttons, you can send the BCM_SETSHIELD message. Is there something similar for message boxes?

Answer 1

Buttons in a message dialog are standard buttons, you can send them a BCM_SETSHIELD message.

For this, you need to be aware when a message dialog box is activated. One way can be to set a temporary WH_CBT hook and in its callback watch for an ‘nCode’ of HCBT_ACTIVATE for a window having the dialog class (#32770).

Another way can be to handle WM_ACTIVATE after ‘MessageBox’ is called, ‘wParam’ should be WA_ACTIVE and ‘lParam’ should be a window handle again of the dialog class. Then you can send the ‘BCM_SETSHIELD’ message to the button f.i. having control id IDOK.