Mnemonics

A mnemonic is a selected letter or digit in the label of a button or in the text of a static control. The system moves the input focus to the control associated with the mnemonic whenever the user either presses the key that corresponds to the mnemonic or presses this key and the alt key in combination. Mnemonics provide a quick way for the user to move to a given control by using the keyboard.

An application creates a mnemonic for a control by inserting the ampersand (&) immediately before the selected letter or digit in the label or text for the control. In most cases, the null-terminated string provided with the control in the dialog box template contains the ampersand. However, an application can create a mnemonic at any time by replacing a control's existing label or text by using the SetDlgItemText function. Only one mnemonic can be given for each control. Although it is recommended, mnemonics in a dialog box need not be unique.

When the user presses a letter or digit key, the system first determines whether the current control having the input focus processes the key. The system sends a WM_GETDLGCODE message to the control, and if the control returns the DLGC_WANTALLKEYS or DLG_WANTMESSAGE value, the system passes the key to the control. Otherwise, it searches for a control whose mnemonic matches the given letter or digit. It continues to search until it locates a control or has examined all controls. During the search, it skips any static controls that have the SS_NOPREFIX style.

If the system locates a static control and the control is not disabled, the system moves the input focus to the first control after the static control that is visible, not disabled, and that has the WS_TABSTOP style. If the system locates some other control that has a matching mnemonic, it moves the input focus to that control. If the control is a default push button, the system sends a BN_CLICKED notification message to the dialog box procedure. If the control is another style of button and there is no other control in the dialog box having the same mnemonic, the system sends the BM_CLICK message to the control.