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4/8/2010

This 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.

Syntax 

int MessageBox(
  HWND 
hWnd, 
  LPCTSTR 
lpText, 
  LPCTSTR 
lpCaption, 
  UINT 
uType
);

Parameters

hWnd

[in] Handle to the owner window of the message box to be created. If this parameter is NULL, the message box has no owner window.

lpText

[in] Long pointer to a null-terminated string that contains the message to be displayed.

lpCaption

[in] Long pointer to a null-terminated string used for the dialog box title. If this parameter is NULL, the default title Error is used.

uType

[in] 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.

Value Description

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: OKand Cancel.

MB_RETRYCANCEL

The message box contains two push buttons: Retryand Cancel.

MB_YESNO

The message box contains two push buttons: Yesand 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.

Value Description

MB_ICONEXCLAMATION, MB_ICONWARNING

An exclamation-point icon appears in the message box.

MB_ICONINFORMATION, MB_ICONASTERISK

An icon consisting of a lowercase letter iin 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.

Value Description

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.

The following flag is the default modality of the dialog box.

Value Description

MB_APPLMODAL

The user must respond to the message box before continuing work in the window identified by the hWndparameter. However, the user can move to the windows of other threads and work in those windows.

Depending on the hierarchy of windows in the application, the user may be able to move to other windows within the thread. All child windows of the parent of the message box are automatically disabled, but popup windows are not.

In addition, you can specify the following flags.

Value Description

MB_SETFOREGROUND

The message box becomes the foreground window. Internally, the system calls the SetForegroundWindowfunction for the message box.

MB_TOPMOST

The message box is created with the WS_EX_TOPMOST window style.

MB_RTLREADING

The message box displays message and caption text using right-to-left reading order on Hebrew and Arabic systems.

Return Value

Zero indicates that there is not enough memory to create the message box.

Upon success, one of the values described in the following table is returned.

Value Description

IDABORT

Abortbutton was selected.

IDCANCEL

Cancelbutton or the close button on the title bar was selected.

IDIGNORE

Ignorebutton was selected.

IDNO

Nobutton was selected.

IDOK

OKbutton was selected.

IDRETRY

Retrybutton was selected.

IDYES

Yesbutton was selected.

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

Remarks

If you create a message box while a dialog box is present, use the handle of the dialog box as the hWndparameter. The hWndparameter should not identify a child window, such as a control in a dialog box.

Requirements

Header windows.h
Library Msgbox.lib
Windows Embedded CE Windows CE 1.0 and later
Windows Mobile Windows Mobile Version 5.0 and later

See Also