Button-control messages are sent by an application to a button control. The following list briefly describes each button-control message:
| Message | Description | |
| BM_GETCHECK | Determines whether a radio button or check box is checked. | |
| BM_GETSTATE | Returns nonzero if the cursor is over the button and the user presses the mouse button or the SPACEBAR. | |
| BM_SETCHECK | Checks or removes the checkmark from a radio button or check box. | |
| BM_SETSTATE | Highlights a button or check box. | |
| BM_SETSTYLE | Alters the style of a button. | |
| DM_GETDEFID | Retrieves the ID of the default push-button control for a dialog box. | |
| DM_SETDEFID | Changes the default push-button control ID for a dialog box. |