一个类似QQ登陆框的EDIT

网易的登陆框也有这个功能，就是其中显示一串提示字符，当用户把输入焦点定位到EDIT中后，提示信息自动消失，这个类很简单，所以我没有做demo，大家看一下就会用了。

.h文件：

#if !defined(AFX_STEDIT_H__FA85F3FB_68AC_48E7_8108_5A61A09148CE__INCLUDED_)#define AFX_STEDIT_H__FA85F3FB_68AC_48E7_8108_5A61A09148CE__INCLUDED_

#if _MSC_VER > 1000#pragma once#endif // _MSC_VER > 1000// STEdit.h : header file//

/// CSTEdit window

class CSTEdit : public CEdit{// Constructionpublic: CSTEdit();

// Attributespublic:

// Operationspublic:

// Overrides // ClassWizard generated virtual function overrides //{{AFX_VIRTUAL(CSTEdit) protected: virtual LRESULT DefWindowProc(UINT message, WPARAM wParam, LPARAM lParam); //}}AFX_VIRTUAL

// Implementationpublic: virtual ~CSTEdit();

 // Generated message map functionsprotected: int nSetText; //{{AFX_MSG(CSTEdit) afx_msg void OnLButtonDown(UINT nFlags, CPoint point); afx_msg void OnSetFocus(CWnd* pOldWnd); //}}AFX_MSG

 DECLARE_MESSAGE_MAP()};

/

//{{AFX_INSERT_LOCATION}}// Microsoft Visual C++ will insert additional declarations immediately before the previous line.

#endif // !defined(AFX_STEDIT_H__FA85F3FB_68AC_48E7_8108_5A61A09148CE__INCLUDED_)

.cpp文件：

// STEdit.cpp : implementation file//

#include "stdafx.h"#include "STEdit.h"

#ifdef _DEBUG#define new DEBUG_NEW#undef THIS_FILEstatic char THIS_FILE[] = __FILE__;#endif

/// CSTEdit

CSTEdit::CSTEdit(){ nSetText = 0;}

CSTEdit::~CSTEdit(){}

BEGIN_MESSAGE_MAP(CSTEdit, CEdit) //{{AFX_MSG_MAP(CSTEdit) ON_WM_LBUTTONDOWN() ON_WM_SETFOCUS() //}}AFX_MSG_MAPEND_MESSAGE_MAP()

/// CSTEdit message handlers

LRESULT CSTEdit::DefWindowProc(UINT message, WPARAM wParam, LPARAM lParam) { if (nSetText < 2)  if (WM_SETTEXT == message)   nSetText++;  else if (WM_CHAR == message)   nSetText = 2;

 return CEdit::DefWindowProc(message, wParam, lParam);}

void CSTEdit::OnLButtonDown(UINT nFlags, CPoint point) { if (1 == nSetText)  SetWindowText("");

 CEdit::OnLButtonDown(nFlags, point);}

void CSTEdit::OnSetFocus(CWnd* pOldWnd) { CEdit::OnSetFocus(pOldWnd); if (1 == nSetText && IsWindowVisible() && pOldWnd && GetParent() == pOldWnd->GetParent())  SetWindowText("");}

大家自行将其分为.h和.cpp即可，使用的时候，关联一个CSTEdit控制型变量，设置提示信息的时候，用SetWindowText等均可。