sendunit.pas

Delphi 7经典问题解析

unit sendunit;

interface

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

type
  TForm1 = class(TForm)
    Edit1: TEdit;
    Label1: TLabel;
    BitBtn1: TBitBtn;
    Label2: TLabel;
    Edit2: TEdit;
    BitBtn2: TBitBtn;
    procedure BitBtn1Click(Sender: TObject);
    procedure BitBtn2Click(Sender: TObject);
  private
    { Private declarations }
  public
    procedure SendData;
    { Public declarations }
  end;

Const
 C1= 17856;
 C2= 23589;

var
  Form1: TForm1;

implementation

{$R *.dfm}
function EncryptModule(SourceStr:String;Key:Word;N:Integer):String;
var
 I:Integer;
begin
 SetLength(Result,Length(SourceStr));//利用SetLength函数指定密文长度
 //对每一个索引元素进行变换
 for I:=1 to Length(SourceStr) do
  begin
   Result[I]:=Char(byte(SourceStr[I]) xor (Key Shr N));
   Key:= (byte(Result[I]) + Key)*C1+C2;
  end;
end;

procedure TForm1.SendData; //发送消息和数据过程
var
Copydatastruct: TCopyDataStruct; //定义一个Tcopydatastruct类型的变量
hwnd: THandle; //句柄类型，用于存储目标对象的句柄
begin 
Copydatastruct.cbData := Length (Edit1.Text) + 1; 

//为传递的数据区分配内存并把要传送的字符串放入数据区
GetMem (Copydatastruct.lpData, Copydatastruct.cbData ); 
StrCopy (Copydatastruct.lpData, PChar (Edit1.Text)); 

// 获得接收窗口的句柄
Hwnd := FindWindow (nil, '利用WM_COPYDATA交换数据Receive改进版');

// 如果目标对象存在，则向其发送WM_COPYDATA消息
if Hwnd <> 0 then 
SendMessage (Hwnd, WM_COPYDATA, Handle, Cardinal(@Copydatastruct)) 
else 
ShowMessage ('目标对象窗口没找到！'); 

//释放资源
FreeMem (Copydatastruct.lpData);
end;

procedure TForm1.BitBtn1Click(Sender: TObject);
begin
 if Edit1.Text<>'' then
  SendData;
end;

procedure TForm1.BitBtn2Click(Sender: TObject);
begin
 Edit1.Text:=EncryptModule(Edit2.Text,12345,10);
end;

end.