一个关于wm_copydata的问题

caike 2010-01-22 12:25:46

我在delphi2010中写了以下代码测试wm_copydata传送数据，但发现总是乱码：
传送端：



unit Unit1;



interface



uses

  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,

  Dialogs, StdCtrls;



type

  TForm1 = class(TForm)

    Button1: TButton;

    Edit1: TEdit;

    Memo1: TMemo;

    procedure Button1Click(Sender: TObject);

  private

    { Private declarations }

    procedure SendText(hwndSend:THandle;str:string);

  public

    { Public declarations }

  end;



const

  Mesg=1600;



var

  Form1: TForm1;



implementation



{$R *.dfm}



procedure TForm1.Button1Click(Sender: TObject);

var

  fhandle:THandle;

begin

  fhandle:=FindWindow(nil,'测试接收WM_COPYDATA');

  if fhandle>0 then

    SendText(fhandle,Edit1.text);

end;



procedure TForm1.SendText(hwndSend:THandle;str: string);

var

  buf:pchar;

  bufflength:integer;

  databuffer:TCopyDataStruct;

begin

  bufflength:=length(str)+1;

  buf:=allocmem(bufflength);

  Strcopy(buf,PChar(str));

  try

    databuffer.dwData:=Mesg;

    databuffer.cbData:=bufflength;

    databuffer.lpData:=buf;



    SendMessage(hwndSend,WM_COPYDATA,handle,LongInt(@databuffer));

  finally

   freemem(buf,bufflength);

  end;

end;



end.





接收端：

unit receive;



interface



uses

  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,

  Dialogs, StdCtrls;



CONST

  cMsg=1600;



type

  TForm1 = class(TForm)

    Memo1: TMemo;

  private

    { Private declarations }

    procedure WMCOPYData(var Mesg:TMessage);message WM_COPYDATA;

  public

    { Public declarations }

  end;



var

  Form1: TForm1;



implementation



{$R *.dfm}



{ TForm1 }



procedure TForm1.WMCOPYData(var Mesg: TMessage);

var

  s:string;

begin

  if PCopyDataStruct(Mesg.lParam)^.dwData=cMsg then

  begin

     s:=Pchar(PCopyDataStruct(mesg.lparam)^.lpData);

     Memo1.Lines.add(s);

  end;

end;



end.

出现二个奇怪问题：
1、在delphi2010中，接收端显示的数据是乱码。
2、在delphi7中上面的代码执行正常，接收端可以正常接收发送端发过来的字符串。
但是如果将接收端的WMCOPYDATA方法中的
s:=Pchar(PCopyDataStruct(mesg.lparam)^.lpData);
Memo1.Lines.add(s);
改成memo1.lines.add(Pchar(PCopyDataStruct(mesg.lparam)^.lpData))，则在接收端中也显示为乱码。

造成上述问题的原因是什么？？还请各位高手指点，谢谢！

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