Question

关于c++messageBox函数

int nSelect = ::MessageBox(NULL, "Hello, Windows XP", "Greetings", MB_OKCANCEL); 我是一个电脑编程初学者，我想问一下messageBox前面的两个冒号是有什么用，为什么可以这么用，还有就是messageBox里面的几个参数，是自己定义的，还是系统自带的，每个又是什么意思啊 ！ 请高手们放着耐心回答一下，帮一下忙啊 ！ 呵呵 谢谢了

Answer 1

前面两个冒号是作用域运算符，代表调用的是CWND类的成员函数。
该函数是已经定义好的。如有错误，欢迎指正。

建议你看看孙鑫老师的《深入详解MFC》，很适合初学者。我现在也在学~~
建议你装MSDN。

下面是MCDN对MessageBox函数的定义：
CWnd::MessageBox
int MessageBox( LPCTSTR lpszText, LPCTSTR lpszCaption = NULL, UINT nType = MB_OK );

Return Value

Specifies the outcome of the function. It is 0 if there is not enough memory to create the message box.

Parameters

lpszText

Points to a CString object or null-terminated string containing the message to be displayed.

lpszCaption

Points to a CString object or null-terminated string to be used for the message-box caption. If lpszCaption is NULL, the default caption “Error” is used.

nType

Specifies the contents and behavior of the message box.

Remarks

Creates and displays a window that contains an application-supplied message and caption, plus a combination of the predefined icons and pushbuttons described in the Message-Box Styles list. Use the global function AfxMessageBox instead of this member function to implement a message box in your application.

The following shows the various system icons that can be used in a message box:

MB_ICONHAND, MB_ICONSTOP, and MB_ICONERROR
MB_ICONQUESTION
MB_ICONEXCLAMATION and MB_ICONWARNING
MB_ICONASTERISK and MB_ICONINFORMATION

Answer 2

我也是菜鸟。。。不过我知道这个函数时可以在MSDN找到的，里面都有解释的