如何从一个Delphi程序实例发送字符串到另一个实例？

Question

从我的程序的一个实例发送字符串到我的程序的另一个实例的最佳和最简单的方法是什么？接收程序必须使用接收的字符串作为参数来执行过程.

我开始阅读DDE,但我感到困惑.我还有其他选择,实现这个的最简单方法是什么？

Answer 1

使用命名管道,但我会推荐Russell Libby的命名管道组件.有一个TPipeClient和TPipeServer组件.

截至(2013-10-04)Francoise Piette和arno.garrels@gmx.de更新了这个源代码,用Delphi 7编译成XE5(早期版本可以编译但未经测试)并将其放在此处: http://www.overbyte .BE/frame_index.html？redirTo =/blog_source_code.html

这两个组件使命名管道非常容易使用,命名管道非常适合进程间通信(IPC).

他的网站在这里.寻找"Pipes.zip".源代码的描述是://描述:Delphi的客户端和服务器命名管道组件集合,以及//控制台管道重定向组件.

此外,Russell帮助我在Experts-Exchange上使用该组件的旧版本在控制台应用程序中工作,以通过命名管道发送/接收消息.这可能有助于您使用他的组件启动和运行.请注意,在VCL应用程序或服务中,您不需要像在此控制台应用程序中那样编写自己的消息循环.

program CmdClient;
{$APPTYPE CONSOLE}

uses
  Windows, Messages, SysUtils, Pipes;

type
  TPipeEventHandler =  class(TObject)
  public
     procedure  OnPipeSent(Sender: TObject; Pipe: HPIPE; Size: DWORD);
  end;

procedure TPipeEventHandler.OnPipeSent(Sender: TObject; Pipe: HPIPE; Size: DWORD);
begin
  WriteLn('On Pipe Sent has executed!');
end;

var
  lpMsg:         TMsg;
  WideChars:     Array [0..255] of WideChar;
  myString:      String;
  iLength:       Integer;
  pcHandler:     TPipeClient;
  peHandler:     TPipeEventHandler;

begin

  // Create message queue for application
  PeekMessage(lpMsg, 0, WM_USER, WM_USER, PM_NOREMOVE);

  // Create client pipe handler
  pcHandler:=TPipeClient.CreateUnowned;
  // Resource protection
  try
     // Create event handler
     peHandler:=TPipeEventHandler.Create;
     // Resource protection
     try
        // Setup clien pipe
        pcHandler.PipeName:='myNamedPipe';
        pcHandler.ServerName:='.';
        pcHandler.OnPipeSent:=peHandler.OnPipeSent;
        // Resource protection
        try
           // Connect
           if pcHandler.Connect(5000) then
           begin
              // Dispatch messages for pipe client
              while PeekMessage(lpMsg, 0, 0, 0, PM_REMOVE) do DispatchMessage(lpMsg);
              // Setup for send
              myString:='the message I am sending';
              iLength:=Length(myString) + 1;
              StringToWideChar(myString, wideChars, iLength);
              // Send pipe message
              if pcHandler.Write(wideChars, iLength * 2) then
              begin
                 // Flush the pipe buffers
                 pcHandler.FlushPipeBuffers;
                 // Get the message
                 if GetMessage(lpMsg, pcHandler.WindowHandle, 0, 0) then DispatchMessage(lpMsg);
              end;
           end
           else
              // Failed to connect
              WriteLn('Failed to connect to ', pcHandler.PipeName);
        finally
           // Show complete
           Write('Complete...');
           // Delay
           ReadLn;
        end;
     finally
        // Disconnect event handler
        pcHandler.OnPipeSent:=nil;
        // Free event handler
        peHandler.Free;
     end;
  finally
     // Free pipe client
     pcHandler.Free;
  end;

end.

Answer 2

我为此使用命名管道,这是我发现的最简单的管道.我下班回家后会发布代码.

这是一篇关于如何在delphi中使用它的文章:http://www.delphi3000.com/articles/article_2918.asp？ SC =

顺便提一下,有一百万种解决方案,所有这些解决方案似乎都很烦人.管道是迄今为止我发现的最好的管道.

这是代码,对延迟感到抱歉.您应该查看Mick提到的管道库.我在这里做的事情是一个非常快速的实验.请注意,它是在Delphi 2009中制作的.

unit PetriW.Pipes;

interface

uses
  Windows,
  Classes,
  Forms,
  SyncObjs,
  SysUtils
  ;

type
  TPBPipeServerReceivedDataEvent = procedure(AData: string) of object;

  TPBPipeServer = class
  private
    type
      TPBPipeServerThread = class(TThread)
      private
        FServer: TPBPipeServer;
      protected
      public
        procedure Execute; override;

        property  Server: TPBPipeServer read FServer;
      end;
  private
    FOnReceivedData: TPBPipeServerReceivedDataEvent;
    FPath: string;
    FPipeHandle: THandle;
    FShutdownEvent: TEvent;
    FThread: TPBPipeServerThread;
  protected
  public
    constructor Create(APath: string);
    destructor Destroy; override;

    property  Path: string read FPath;

    property  OnReceivedData: TPBPipeServerReceivedDataEvent read FOnReceivedData write FOnReceivedData;
  end;

  TPBPipeClient = class
  private
    FPath: string;
  protected
  public
    constructor Create(APath: string);
    destructor Destroy; override;

    property  Path: string read FPath;

    procedure SendData(AData: string); overload;
    class procedure SendData(APath, AData: string); overload;
  end;

implementation

const
  PIPE_MESSAGE_SIZE = $20000;

{ TPipeServer }

constructor TPBPipeServer.Create(APath: string);
begin
  FPath := APath;

  FShutdownEvent := TEvent.Create(nil, True, False, '');

  FPipeHandle := CreateNamedPipe(
    PWideChar(FPath),
    PIPE_ACCESS_DUPLEX or FILE_FLAG_OVERLAPPED,
    PIPE_TYPE_MESSAGE or PIPE_READMODE_MESSAGE or PIPE_WAIT,
    PIPE_UNLIMITED_INSTANCES,
    SizeOf(Integer),
    PIPE_MESSAGE_SIZE,
    NMPWAIT_USE_DEFAULT_WAIT,
    nil
  );

  if FPipeHandle = INVALID_HANDLE_VALUE then
    RaiseLastOSError;

  FThread := TPBPipeServerThread.Create(true);
  FThread.FreeOnTerminate := false;
  FThread.FServer := self;
  FThread.Resume;
end;

destructor TPBPipeServer.Destroy;
begin
  FShutdownEvent.SetEvent;
  FreeAndNil(FThread);
  CloseHandle(FPipeHandle);
  FreeAndNil(FShutdownEvent);

  inherited;
end;

{ TPipeServer.TPipeServerThread }

procedure TPBPipeServer.TPBPipeServerThread.Execute;
var
  ConnectEvent, ReadEvent: TEvent;
  events: THandleObjectArray;
  opconnect, opread: TOverlapped;
  Signal: THandleObject;
  buffer: TBytes;
  bytesRead, error: Cardinal;
begin
  inherited;

  //SetThreadName('TPBPipeServer.TPBPipeServerThread');

  ConnectEvent := TEvent.Create(nil, False, False, '');
  try
    setlength(events, 2);
    events[1] := Server.FShutdownEvent;

    FillMemory(@opconnect, SizeOf(TOverlapped), 0);
    opconnect.hEvent := ConnectEvent.Handle;

    while not Terminated do
    begin
      ConnectNamedPipe(Server.FPipeHandle, @opconnect);

      events[0] := ConnectEvent;
      THandleObject.WaitForMultiple(events, INFINITE, False, Signal);
      if Signal = ConnectEvent then
      try
        // successful connect!
        ReadEvent := TEvent.Create(nil, True, False, '');
        try
          FillMemory(@opread, SizeOf(TOverlapped), 0);
          opread.hEvent := ReadEvent.Handle;
          setlength(buffer, PIPE_MESSAGE_SIZE);

          if not ReadFile(Server.FPipeHandle, buffer[0], PIPE_MESSAGE_SIZE, bytesRead, @opread) then
          begin
            error := GetLastError;
            if error = ERROR_IO_PENDING then
            begin
              if not GetOverlappedResult(Server.FPipeHandle, opread, bytesRead, True) then
                error := GetLastError
              else
                error := ERROR_SUCCESS;
            end;
            if error = ERROR_BROKEN_PIPE then
              // ignore, but discard data
              bytesRead := 0
            else if error = ERROR_SUCCESS then
              // ignore
            else
              RaiseLastOSError(error);
          end;

          if (bytesRead > 0) and Assigned(Server.OnReceivedData) then
            Server.OnReceivedData(TEncoding.Unicode.GetString(buffer, 0, bytesRead));

          // Set result to 1
          PInteger(@buffer[0])^ := 1;
          if not WriteFile(Server.FPipeHandle, buffer[0], SizeOf(Integer), bytesRead, @opread) then
          begin
            error := GetLastError;
            if error = ERROR_IO_PENDING then
            begin
              if not GetOverlappedResult(Server.FPipeHandle, opread, bytesRead, True) then
                error := GetLastError
              else
                error := ERROR_SUCCESS;
            end;
            if error = ERROR_BROKEN_PIPE then
              // ignore
            else if error = ERROR_SUCCESS then
              // ignore
            else
              RaiseLastOSError(error);
          end;
        finally
          FreeAndNil(ReadEvent);
        end;
      finally
        DisconnectNamedPipe(Server.FPipeHandle);
      end
      else if Signal = Server.FShutdownEvent then
      begin
        // server is shutting down!
        Terminate;
      end;
    end;
  finally
    FreeAndNil(ConnectEvent);
  end;
end;

{ TPBPipeClient }

constructor TPBPipeClient.Create(APath: string);
begin
  FPath := APath;
end;

destructor TPBPipeClient.Destroy;
begin

  inherited;
end;

class procedure TPBPipeClient.SendData(APath, AData: string);
var
  bytesRead: Cardinal;
  success: Integer;
begin
  if not CallNamedPipe(PWideChar(APath), PWideChar(AData), length(AData) * SizeOf(Char), @success, SizeOf(Integer), bytesRead, NMPWAIT_USE_DEFAULT_WAIT) then
    RaiseLastOSError;
end;

procedure TPBPipeClient.SendData(AData: string);
var
  bytesRead: Cardinal;
  success: boolean;
begin
  if not CallNamedPipe(PWideChar(FPath), PWideChar(AData), length(AData) * SizeOf(Char), @success, SizeOf(Integer), bytesRead, NMPWAIT_USE_DEFAULT_WAIT) then
    RaiseLastOSError;
end;

end.

这是我发送的东西:

TPBPipeClient.SendData('\\.\pipe\pipe server E5DE3B9655BE4885ABD5C90196EF0EC5', 'HELLO');

这是我读的东西:

procedure TfoMain.FormCreate(Sender: TObject);
begin
  PipeServer := TPBPipeServer.Create('\\.\pipe\pipe server E5DE3B9655BE4885ABD5C90196EF0EC5');
  PipeServer.OnReceivedData := PipeDataReceived;
end;

procedure TfoMain.PipeDataReceived(AData: string);
begin
  if AData = 'HELLO' then
    // do something, but note that you're not in the main thread, you're in the pipe server thread
end;

Answer 3

对于非常短的消息,WM_COPYDATA可能是最简单的.除此之外,PetriW建议使用命名管道或插座.

Answer 4

见JclAppInstances在JCL.