API 关闭窗口解决方法

API 关闭窗口
比如说 我新建了一个MDI窗体,然后有很多子窗体,在MDI内打开后 怎么用API函数关闭打开的子窗口,平常我们用的是UNLOAD ME 怎么用API函数替换这个功能

------解决方案--------------------
使用SendMessage发送关闭命令给它即可
VB code

Private   Declare   Function   SendMessage   Lib   "user32 "   Alias   "SendMessageA "   (ByVal   hWnd   As   Long,   ByVal   wMsg   As   Long,   ByVal   wParam   As   Long,   lParam   As   Any)   As   Long 

Private   Sub   Command1_Click(Index   As   Integer) 
  dim   quit   as   long 
  quit   =   SendMessage(hWnd,   WM_CLOSE,   0,   0) 
END   Sub