单击按钮 出现提示对话框，然后点击确定，更改变量值
if (GetTagBit("fafa")==0)  //fafa就是你说的变量A
{
int  xRet = MessageBox(NULL,"要将该变量置位为1啦","提示",
MB_OK|MB_ICONEXCLAMATION|MB_SETFOREGROUND|MB_SYSTEMMODAL);
//int xRet = MessageBox(NULL,szBuffer,"确认窗口",MB_YESNO|MB_ICONQUESTION|MB_SYSTEMMODAL);//message 
if (xRet==IDOK)
{
SetTagBit("fafa",1); //Return-Type: BOOL 
}
}
else
{
int  xRet = MessageBox(NULL,"要将该变量复位为0啦","提示",
MB_OK|MB_ICONEXCLAMATION|MB_SETFOREGROUND|MB_SYSTEMMODAL);
if (xRet==IDOK)
{
SetTagBit("fafa",0); //Return-Type: BOOL 

}
}