什么是从程序的一个实例发送字符串到另一个实例的最佳和最简单的方法?接收程序必须执行一个过程,使用接收到的字符串作为参数。
我开始了解DDE,但我感到困惑。我还有哪些选项,并且实现这个功能最简单的方法是什么?
什么是从程序的一个实例发送字符串到另一个实例的最佳和最简单的方法?接收程序必须执行一个过程,使用接收到的字符串作为参数。
我开始了解DDE,但我感到困惑。我还有哪些选项,并且实现这个功能最简单的方法是什么?
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.
我使用命名管道来实现这个,发现它是最简单的解决方法。等我下班后会发布代码。
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?SK=
顺便提一下,有成千上万种解决方案,但它们似乎都很烦人,而管道是我目前发现的最好的解决方法。
这是代码,对于延迟我感到抱歉。你也应该查看Mick提到的Pipe库。这里我做了一个相当快速的实验,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.
这是我发送某个东西的方式:
TPBPipeClient.SendData('\\.\pipe\pipe server E5DE3B9655BE4885ABD5C90196EF0EC5', 'HELLO');
这是我阅读内容的方式:
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;
请参阅JclAppInstances,该内容与JCL有关。