sendmessage如何发送结构体数据
我的代码如下

Delphi(Pascal) code

. type  TDATA = record     MissionName :string;     sTime       :string;     Completed   :string;     Mission     :string;     MissionCnt  :string; end;......var  DATA:^TDATA;begin  New(DATA);  DATA^.MissionName:=edtMissionName.Text;   //，编译没问题，运行到这里就出错  DATA^.Completed:='0';  DATA^.sTime:=DateToStr(DateTimePicker1.Date) + ' ' + edtTime.Text;  DATA^.Mission:=mmoMission.Text;  DATA^.MissionCnt:=MmoCnt.Text;  SendMessage(FrmMission.Handle,MyMessage,0,lparam(DATA));

[解决办法]
Record的使用有问题罢？跟发送消息无关
DATA后面的尖括号去掉：）
type
myData=^TData;
TDATA = record
MissionName :string;
sTime :string;
Completed :string;
Mission :string;
MissionCnt :string;
end;

调用：
var ss:myData;
begin
new(ss);
ss.MissionName:='test';
dispose(ss);
end;
[解决办法]
楼主自定义消息发送内容，请参看这个单元，使用的WM_COPYDATA消息，他用的是两个应用程序之间的通信：）道理是一样的，我就不再照着去改写了
请看这个单元的SendData方法，界面很简单：就是发送0：字符串；1：Image；2：Record；消息的Handle有所变化
unit SenderMain;

{

How to send information (String, Image, Record) between two Delphi applications

http://delphi.about.com/od/windowsshellapi/a/wm_copydata.htm

Learn how to send the WM_CopyData message between two Delphi
applications to exchange information and make two applications
communicate. The accompanying source code demonstrates how to
send a string, record (complex data type) and even graphics
to another application.


~Zarko Gajic
About Delphi Programming
http://delphi.about.com
}

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls, ExtCtrls;

type

(*
Declared in Windows.pas

TCopyDataStruct = packed record
dwData: DWORD; //up to 32 bits of data to be passed to the receiving application
cbData: DWORD; //the size, in bytes, of the data pointed to by the lpData member
lpData: Pointer; //Points to data to be passed to the receiving application. This member can be nil.
end;

*)
TCopyDataType = (cdtString = 0, cdtImage = 1, cdtRecord = 2);

TSampleRecord = packed record
s : string[50];
i : integer;
d : TDateTime;
end;


TSenderMainForm = class(TForm)
SendDataButton: TButton;
rgCopyOptions: TRadioGroup;
procedure SendDataButtonClick(Sender: TObject);
private
procedure SendData(copyDataStruct : TCopyDataStruct);

procedure SendString();
procedure SendImage();
procedure SendRecord();
public
{ Public declarations }
end;

var
SenderMainForm: TSenderMainForm;

implementation

{$R *.dfm}

procedure TSenderMainForm.SendData(
copyDataStruct: TCopyDataStruct);
var
receiverHandle : THandle;
res : integer;
begin
receiverHandle := FindWindow(PChar('TReceiverMainForm'),PChar('ReceiverMainForm'));
if receiverHandle = 0 then
begin
ShowMessage('CopyData Receiver NOT found!');
Exit;
end;

res := SendMessage(receiverHandle, WM_COPYDATA, Integer(Handle), Integer(@copyDataStruct));

if res > 0 then ShowMessage(Format('Receiver has %d lines in Memo!',[res]));
end;

procedure TSenderMainForm.SendDataButtonClick(Sender: TObject);
begin
if rgCopyOptions.ItemIndex = -1 then
begin
ShowMessage('Nothing selected!');
Exit;
end;

case rgCopyOptions.ItemIndex of

0 : SendString;
1 : SendImage;
2 : SendRecord;
end;
end;

procedure TSenderMainForm.SendImage();
var
ms : TMemoryStream;
bmp : TBitmap;
copyDataStruct : TCopyDataStruct;
begin
ms := TMemoryStream.Create;
try
bmp := self.GetFormImage;
try
bmp.SaveToStream(ms);
finally
bmp.FreeImage;
end;
copyDataStruct.dwData := Integer(cdtImage); //use it to identify the message contents
copyDataStruct.cbData := ms.Size;
copyDataStruct.lpData := ms.Memory;

SendData(copyDataStruct);
finally
ms.Free;
end;
end;

procedure TSenderMainForm.SendRecord();
var
sampleRecord : TSampleRecord;
copyDataStruct : TCopyDataStruct;
begin
sampleRecord.s := 'Hello Receiver';
sampleRecord.i := 1973;
sampleRecord.d := Now;

copyDataStruct.dwData := Integer(cdtRecord); //use it to identify the message contents
copyDataStruct.cbData := SizeOf(sampleRecord);
copyDataStruct.lpData := @sampleRecord;

SendData(copyDataStruct);

end;

procedure TSenderMainForm.SendString();
var
stringToSend : string;
copyDataStruct : TCopyDataStruct;
begin
stringToSend := 'About Delphi Programming';

copyDataStruct.dwData := Integer(cdtString); //use it to identify the message contents
copyDataStruct.cbData := 1 + Length(stringToSend);
copyDataStruct.lpData := PChar(stringToSend);

SendData(copyDataStruct);
end;

end.