LWA_COLORKEY undeclared identifier 的办理步伐

<pre class="cpp" name="code">SetWindowLong(this->GetSafeHwnd(),   
              
        GWL_EXSTYLE,   
              
        GetWindowLong(this->GetSafeHwnd(),GWL_EXSTYLE)^0x80000); </pre><br>  
<pre></pre>  
<pre class="cpp" name="code">HINSTANCE hInst = LoadLibrary("User32.DLL");   
          
    if(hInst)   
              
    {   
              
           typedef BOOL (WINAPI *MYFUNC)(HWND,COLORREF,BYTE,DWORD);   
                 
           MYFUNC fun = NULL;   
                 
           //取得SetLayeredWindowAttributes函数指针   
                 
           fun=(MYFUNC)GetProcAddress(hInst, "SetLayeredWindowAttributes");   
                 
           if(fun)  
           {  
               //fun(this->GetSafeHwnd(),0,129,2);   
                fun(this->GetSafeHwnd(),GetSysColor(COLOR_BTNFACE), 129, LWA_COLORKEY);   
           }  
                 
           FreeLibrary(hInst);   
    }</pre>  
<p><br>  
利用以上要领实现半透明窗口时，</p>  
<p>编译时输出如下：</p>  
<p>error C2065: 'LWA_COLORKEY' : undeclared identifier</p>  
<p> </p>  
<p>显着引入了相关的头文件：#include "WinUser.h"，怎么还会提示'LWA_COLORKEY'未界说呢？</p>  
<p>查察头文件件中的界说发明，是条件界说的问题；</p>  
<p> </p>  
<p>在：#include "WinUser.h"之前添加：#define _WIN32_WINNT 0x0502</p>  
<p>问题办理；</p>

作者：csdn博客 微wx笑