MessageBox

The MessageBox function creates, displays, and operates a message box. The message box contains an application-defined message and title, plus any combination of predefined icons and push buttons.

number MessageBox(
  string lpText,     // text in message box
  string lpCaption,  // title of message box
  dword uType          // style of message box
  dword hWnd,          // handle of owner window
);
 

Parameters

lpText
Pointer to a null-terminated string containing the message to be displayed.
lpCaption
Pointer to a null-terminated string used for the dialog box title. If this parameter is NULL, the default title Error is used.
uType
Specifies a set of bit flags that determine the contents and behavior of the dialog box. This parameter can be a combination of flags from the following groups of flags.

Specify one of the following flags to indicate the buttons contained in the message box:
Flag Meaning
MB_ABORTRETRYIGNORE The message box contains three push buttons: Abort, Retry, and Ignore.
MB_OK The message box contains one push button: OK. This is the default.
MB_OKCANCEL The message box contains two push buttons: OK and Cancel.
MB_RETRYCANCEL The message box contains two push buttons: Retry and Cancel.
MB_YESNO The message box contains two push buttons: Yes and No.
MB_YESNOCANCEL The message box contains three push buttons: Yes, No, and Cancel.

Specify one of the following flags to display an icon in the message box:
Flag Meaning
MB_ICONEXCLAMATION,
MB_ICONWARNING
An exclamation-point icon appears in the message box.
MB_ICONINFORMATION, MB_ICONASTERISK
An icon consisting of a lowercase letter i in a circle appears in the message box.
MB_ICONQUESTION A question-mark icon appears in the message box.
MB_ICONSTOP,
MB_ICONERROR,
MB_ICONHAND
A stop-sign icon appears in the message box.

Specify one of the following flags to indicate the default button:
Flag Meaning
MB_DEFBUTTON1 The first button is the default button.

MB_DEFBUTTON1 is the default unless MB_DEFBUTTON2, MB_DEFBUTTON3, or MB_DEFBUTTON4 is specified.

MB_DEFBUTTON2 The second button is the default button.
MB_DEFBUTTON3 The third button is the default button.
MB_DEFBUTTON4 The fourth button is the default button.

In addition, you can specify the following flags:

MB_DEFAULT_DESKTOP_ONLY
The desktop currently receiving input must be a default desktop; otherwise, the function fails. A default desktop is one an application runs on after the user has logged on.
MB_HELP
Adds a Help button to the message box. Choosing the Help button or pressing F1 generates a Help event.
MB_RIGHT
The text is right-justified.
MB_RTLREADING
Displays message and caption text using right-to-left reading order on Hebrew and Arabic systems.
MB_SETFOREGROUND
The message box becomes the foreground window.
MB_TOPMOST
The message box is created with the WS_EX_TOPMOST window style.
hWnd
Identifies the owner window of the message box to be created. If this parameter is NULL, the message box has no owner window.
 

Return Values

The return value is zero if there is not enough memory to create the message box.

If the function succeeds, the return value is one of the following menu-item values returned by the dialog box:

Value Meaning
IDABORT Abort button was selected.
IDCANCEL Cancel button was selected.
IDIGNORE Ignore button was selected.
IDNO No button was selected.
IDOK OK button was selected.
IDRETRY Retry button was selected.
IDYES Yes button was selected.

If a message box has a Cancel button, the function returns the IDCANCEL value if either the esc key is pressed or the Cancel button is selected. If the message box has no Cancel button, pressing esc has no effect.

Example

if ( IDYES ~= wnd.MessageBox( "Clear canvas?", "Winds3D Painter", orDWORD(MB_YESNO,MB_ICONWARNING) ) )
then
    return
end