Delphi经典实例9------字符串简单加密

利用WM_COPYDATA交换数据演示:

a.发送端：

如下图所示建立工程：

代码如下：

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.

 

b.接受端：

如下图所示建立工程：

代码如下：

unit Receiveunit; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls, Buttons; type TForm1 = class(TForm) Edit1: TEdit; Label1: TLabel; Label2: TLabel; Edit2: TEdit; private { Private declarations } public procedure Capturemessage(var CopyData:TWmCopyData);message WM_COPYDATA; { Public declarations } end; Const C1= 17856; C2= 23589; var Form1: TForm1; implementation {$R *.dfm} function DecryptModule(EncryptStr:String;Key:Word;N:Integer):String; var I:Integer; begin SetLength(Result,Length(EncryptStr)); for I:=1 to Length(EncryptStr) do begin Result[I]:=Char(byte(EncryptStr[I]) xor (Key Shr N)); Key:= (byte(EncryptStr[I])+key)*C1+C2; //注意这里与加密过程的不同 end; end; procedure TForm1.Capturemessage(var CopyData:TWmCopyData); begin // Edit1.text:=StrPas(CopyData.CopyDataStruct^.lpData);//接收数据获取数据并显示 // Edit2.Text:=DecryptModule(StrPas(CopyData.CopyDataStruct^.lpData),12345,10); Edit1.text:=PChar(CopyData.CopyDataStruct^.lpData);//接收数据获取数据并显示 Edit2.Text:=DecryptModule(PChar(CopyData.CopyDataStruct^.lpData),12345,10); end; end.