CWnd创建WS_CHILD和WS_POPUP窗口的不同

转载：http://blog.csdn.net/tangaowen/article/details/6054152

最近在写一个从CWnd派生出来的自绘窗口，以前在包装自己的类的Create函数都是这么写的：

BOOL  CXXX::Create(DWORD dwStyle, const RECT &rect, CWnd *pParentWnd, UINT nID, CCreateContext *pContext)
{
      if (!CWnd::Create(GUOGUOTIPSUPWINDOW_CLASSNAME, NULL, dwStyle, rect, pParentWnd, nID, pContext))
         return FALSE;
      return true;
}  

    这次也这么写，以前都是创建的WS_CHILD的窗口，都是这么调用的：

DWORD  style=WS_CHILD|WS_OVERLAPPED;
    m_tooltips.Create(style,CRect(0,0,300,300),NULLthis,NULL,NULL);

.csharpcode, .csharpcode pre
{
font-size: small;
color: black;
font-family: consolas, "Courier New", courier, monospace;
background-color: #ffffff;
/*white-space: pre;*/
}
.csharpcode pre { margin: 0em; }
.csharpcode .rem { color: #008000; }
.csharpcode .kwrd { color: #0000ff; }
.csharpcode .str { color: #006080; }
.csharpcode .op { color: #0000c0; }
.csharpcode .preproc { color: #cc6633; }
.csharpcode .asp { background-color: #ffff00; }
.csharpcode .html { color: #800000; }
.csharpcode .attr { color: #ff0000; }
.csharpcode .alt
{
background-color: #f4f4f4;
width: 100%;
margin: 0em;
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.csharpcode .lnum { color: #606060; }

    没有任何问题。

    

   这次要创建一个WS_POPUP类型的窗口，当然就按照下面这么调用了：

DWORD  style=WS_POPUP|WS_OVERLAPPED;
    m_tooltips.Create(style,CRect(0,0,300,300),NULL,NULL,NULL);

.csharpcode, .csharpcode pre
{
font-size: small;
color: black;
font-family: consolas, "Courier New", courier, monospace;
background-color: #ffffff;
/*white-space: pre;*/
}
.csharpcode pre { margin: 0em; }
.csharpcode .rem { color: #008000; }
.csharpcode .kwrd { color: #0000ff; }
.csharpcode .str { color: #006080; }
.csharpcode .op { color: #0000c0; }
.csharpcode .preproc { color: #cc6633; }
.csharpcode .asp { background-color: #ffff00; }
.csharpcode .html { color: #800000; }
.csharpcode .attr { color: #ff0000; }
.csharpcode .alt
{
background-color: #f4f4f4;
width: 100%;
margin: 0em;
}
.csharpcode .lnum { color: #606060; }

    但是，结果却crash了，郁闷了。

    查了半天发现，原来是Create函数的实现出了问题。

     CWnd::Create函数只能创建非WS_POPUP的窗口风格的窗口。而如果要创建WS_POPUP的窗口和有扩展风格的窗口，必须调用CWnd::CreateEx才能搞定。

     MSDN对Create的说明：

     Creates and initializes the child window associated with the CWnd object.

     MSDN对CreateEx的说明：

    Creates a Windows overlapped, pop-up, or child window and attaches it to a  CWnd object.

.csharpcode, .csharpcode pre
{
font-size: small;
color: black;
font-family: consolas, "Courier New", courier, monospace;
background-color: #ffffff;
/*white-space: pre;*/
}
.csharpcode pre { margin: 0em; }
.csharpcode .rem { color: #008000; }
.csharpcode .kwrd { color: #0000ff; }
.csharpcode .str { color: #006080; }
.csharpcode .op { color: #0000c0; }
.csharpcode .preproc { color: #cc6633; }
.csharpcode .asp { background-color: #ffff00; }
.csharpcode .html { color: #800000; }
.csharpcode .attr { color: #ff0000; }
.csharpcode .alt
{
background-color: #f4f4f4;
width: 100%;
margin: 0em;
}
.csharpcode .lnum { color: #606060; }

.csharpcode, .csharpcode pre
{
font-size: small;
color: black;
font-family: consolas, "Courier New", courier, monospace;
background-color: #ffffff;
/*white-space: pre;*/
}
.csharpcode pre { margin: 0em; }
.csharpcode .rem { color: #008000; }
.csharpcode .kwrd { color: #0000ff; }
.csharpcode .str { color: #006080; }
.csharpcode .op { color: #0000c0; }
.csharpcode .preproc { color: #cc6633; }
.csharpcode .asp { background-color: #ffff00; }
.csharpcode .html { color: #800000; }
.csharpcode .attr { color: #ff0000; }
.csharpcode .alt
{
background-color: #f4f4f4;
width: 100%;
margin: 0em;
}
.csharpcode .lnum { color: #606060; }