MAKELONG用法

The   MAKELONG   macro   creates   an   unsigned   32-bit   value   by   concatenating   two   given   16-bit   values.    
   
  DWORD   MAKELONG(  
      WORD   wLow,     //   low-order   word   of   long   value  
      WORD   wHigh     //   high-order   word   of   long   value  
  );  
     
  Parameters  
  wLow    
  Specifies   the   low-order   word   of   the   new   long   value.    
  wHigh    
  Specifies   the   high-order   word   of   the   new   long   value.    
  Return   Values  
  The   return   value   is   an   unsigned   32-bit   value.    
   
  Remarks  
  The   MAKELONG   macro   is   defined   as   follows:    
   
  #define   MAKELONG(a,   b)   /    
          ((LONG)   (((WORD)   (a))   |   ((DWORD)   ((WORD)   (b)))   <<   16))  

 

 

DWORD MAKELONG(
WORD wLow, // low-order word of long value
WORD wHigh // high-order word of long value
);

SendMessage(hWnd,WM_LBUTTONDOWN,NULL,MAKELONG(x*cxBlock,y*cyBlock));

 

处理消息：    x = LOWORD(lParam)/cxBlock;
                        y = HIWORD(lParam)/cyBlock;