{
    FindWindow 的两个参数: 第一个: 是类名, 计算器的类名是: SciCalc 第二个: 是标题名 两个参数有其一即可,格式: } h := FindWindow('SciCalc', nil); h := FindWindow(nil, '计算器'); procedure SendMsg(AppName,Msg:string); var   ds: TCopyDataStruct;   handle:THandle; begin   ds.cbData:=Length(Msg)+1;   GetMem(ds.lpData,ds.cbData); try     StrCopy(ds.lpData,PChar(Msg));     handle:=FindWindow(nil,Pchar(AppName));     handle:=FindWindow('TReceiveFrm',nil));     SendMessage(handle, WM_COPYDATA, 0, Integer(@ds)); finally     FreeMem(ds.lpData,ds.cbData); end; end; {
    调用:}   SendMsg('Receie窗口','Hello World'); public procedure WMCopyData(var Msg: TWMCOPYDATA); message WM_COPYDATA; procedure TReceiveFrm.WMCopyData(var Msg: TWMCOPYDATA); begin   showmessage(StrPas(Msg.CopyDataStruct^.lpData)); end;