delphi sendmessge 如何传递字符串内容的信息？

[clark_x]

sendmessage(application.handle, MESSAGE, WPARAM, LPRAM );
怎么放想传递的字符串信息呢？

[clark_x]

如何接收呢？

[clark_x]

我是在两个进程间传递这个消息的 ？ 这个内存信息会出现问题吗？

[miky]

两个程序之间用消息传递数据
两个程序之间用消息传递数据。
问题：我想用SendMessage和自定义消息在两个程序之间传递一个字符串，问题是如果这个字符串是一个常量，SendMessage(h,CM_MYMESSAGE,0,integer(pchar('abcdef')));另外一个程序对CM_MYMESSAGE进行处理可以收到'abcdef'，然而，把abcdef变成一个pchar或者string进行传递，就无法正常使用了！如何解决呢？

解答：可以利用WM_COPYDATA来做。

下面代码仅仅演示，细节错误不予考虑

procedure Init;

var

s : pchar;

h : hwnd;

buf:tagCOPYDATASTRUCT;

begin

h := FindWindow('TForm1', 'Form1');

if h <> 0 then

begin

GetMem(s,100);

buf.lpData :=s;

buf.cbData:=100;

buf.dwData :=100;

strpcopy(s, ParamStr(0));

SendMessage(h, WM_COPYDATA, 0, integer(@buf));

end;

end;

procedure TForm1.WM_COPYDATA(var msg: TMessage);

var

P:^tagCOPYDATASTRUCT;

begin

p:=Pointer(Msg.lParam);

ShowMessage(strpas(p.lpData));

end;

***********************************************************************************

{

The WM_COPYDATA messages makes it possible to transfer information

between processes. It does this by passing the data through the kernel.

Space is allocated in the receiving process to hold the information that is copied,

by the kernel, from the source process to the target process.

The sender passes a pointer to a COPYDATASTRUCT, which is defined as a structure

of the following:

}

type

TCopyDataStruct = packed record

dwData: DWORD; // anwendungsspezifischer Wert

cbData: DWORD; // Byte-L?nge der zu übertragenden Daten

lpData: Pointer; // Adresse der Daten

end;

{ Sender Application }

unit SenderApp;

interface

uses

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

StdCtrls, ExtCtrls;

type

TForm1 = class(TForm)

Button1: TButton;

Edit1: TEdit;

Button2: TButton;

Image1: TImage;

procedure Button1Click(Sender: TObject);

procedure Button2Click(Sender: TObject);

private

procedure SendCopyData(hTargetWnd: HWND; ACopyDataStruct:TCopyDataStruct);

public

end;

var

Form1: TForm1;

implementation

{$R *.DFM}

// Sender: Send data

// Sender: Daten schicken

procedure TForm1.SendCopyData(hTargetWnd: HWND; ACopyDataStruct:TCopyDataStruct);

begin

if hTargetWnd <> 0 then

SendMessage(hTargetWnd, WM_COPYDATA, Longint(Handle), Longint(@ACopyDataStruct))

else

ShowMessage('No Recipient found!');

end;

// Send Text from Edit1 to other app

// Text von Edit1 an andere Anwendung schicken

procedure TForm1.Button1Click(Sender: TObject);

var

MyCopyDataStruct: TCopyDataStruct;

hTargetWnd: HWND;

begin

// Set up a COPYDATASTRUCT structure for use with WM_COPYDATA

// TCopyDataStruct mit den Sende-Daten Infos ausfüllen

with MyCopyDataStruct do

begin

dwData := 0; // may use a value do identify content of message

cbData := StrLen(PChar(Edit1.Text)) + 1; //Need to transfer terminating #0 as well

lpData := PChar(Edit1.Text)

end;

// Find the destination window for the WM_COPYDATA message

// Empf?nger Fenster anhand des Titelzeilentextes suchen

hTargetWnd := FindWindow(nil,PChar('Message Receiver'));

// send the structure to the receiver

// Die Struktur an den Empf?nger schicken

SendCopyData(hTargetWnd, MyCopyDataStruct);

end;

// Send Image1 to other app

// Image1 an andere Anwendung schicken

procedure TForm1.Button2Click(Sender: TObject);

var

ms: TMemoryStream;

MyCopyDataStruct: TCopyDataStruct;

hTargetWnd: HWND;

begin

ms := TMemoryStream.Create;

try

image1.Picture.Bitmap.SaveToStream(ms);

with MyCopyDataStruct do

begin

dwData := 1;

cbData := ms.Size;

lpData := ms.Memory;

end;

// Search window by the window title

// Empf?nger Fenster anhand des Titelzeilentextes suchen

hTargetWnd := FindWindow(nil,PChar('Message Receiver'));

// Send the Data

// Daten Senden

SendCopyData(hTargetWnd,MyCopyDataStruct);

finally

ms.Free;

end;

end;

end.

{*********************************************************************}

{ Receiver Application }

unit ReceiverApp;

interface

uses

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

ExtCtrls, StdCtrls;

type

TForm1 = class(TForm)

Image1: TImage;

Label1: TLabel;

private

procedure WMCopyData(var Msg: TWMCopyData); message WM_COPYDATA;

{ Private-Deklarationen }

public

{ Public-Deklarationen }

end;

var

Form1: TForm1;

implementation

{$R *.DFM}

procedure TForm1.WMCopyData(var Msg: TWMCopyData);

var

sText: array[0..99] of Char;

ms: TMemoryStream;

begin

case Msg.CopyDataStruct.dwData of

0: { Receive Text, Text empfangen}

begin

StrLCopy(sText, Msg.CopyDataStruct.lpData, Msg.CopyDataStruct.cbData);

label1.Caption := sText;

end;

1: { Receive Image, Bild empfangen}

begin

ms := TMemoryStream.Create;

try

with Msg.CopyDataStruct^ do

ms.Write(lpdata^, cbdata);

ms.Position := 0;

image1.Picture.Bitmap.LoadFromStream(ms);

finally

ms.Free;

end;

end;

end;

end;

end.

　

[qizhanfeng]

学习

[clark_x]

我仅仅是传递一个 字符串 而已也而且我用的是自己 RegisterWindowMessage 的消息 ，这样可以保证传递的可靠性 。 不会出现系统其它的一些东东；
实际上，我们现在是使用WM_SETTEXT 来传递的,在这样的一些条件下,如何解决这个问题呢?

[clark_x]

另外还要注明的是 我是用DELPHI 调用 一个 VB (WM_SETTEXT).是VB 传递过来的字符串信息,由于涉及到两公司的开发,可能接口不好改变了 大家有没有好办法?

[miky]

传指针

[楚人无衣]

var
s: string;
begin
s := 'season';
sendmessage(application.handle, MESSAGE, WPARAM, Integer(@s));
...
end;