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Delphi中如何发送广播消息

发布于 2024-09-14 15:13:21 字数 110 浏览 6 评论 0原文

我想在我的局域网中发送广播UDP消息，应用程序是客户端/服务器。

我希望更新用户界面，这样任何计算机都会发送消息来更新其他计算机。我可以使用UDPServer indy吗，如何使用？谢谢

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三生路 2024-09-21 15:13:21

创建两个应用程序，一个代表发送者，另一个代表接收者。

发送者

在表单上放置一个 TIdUDPClient 和一个 TButton 组件。在按钮的 OnClick 处理程序上写入：

procedure TfrmUDPClient.BroadcastClick(Sender: TObject);
begin
  UDPClient.Broadcast('Test', 8090);
end;

Receiver

在表单上放置一个 TIdUDPServer，为其定义相同的端口 (8090) 并将其添加到 OnUDPRead< /code> handler：

procedure TfrmUDPServer.UDPServerUDPRead(Sender: TObject; AData: TStream; ABinding: TIdSocketHandle);
var
  DataStringStream: TStringStream;
  Msg: String;
begin
  DataStringStream := TStringStream.Create('');
  try
    DataStringStream.CopyFrom(AData, AData.Size);
    Msg := DataStringStream.DataString;
  finally
    DataStringStream.Free;
  end;
  ShowMessage(Msg);
end;

或者，在 Indy 的更高版本中：

procedure TfrmUDPServer.UDPServerUDPRead(AThread: TIdUDPListenerThread;
  const AData: TIdBytes; ABinding: TIdSocketHandle);
var
  Msg: String;
begin
  try
    {if you actually sent a string encoded in utf-8}
    Msg := TEncoding.UTF8.GetString(AData);
  except
  end;

  ShowMessage(Msg);
end;

要进行测试，请运行这两个应用程序并单击按钮。要使用两个或更多“侦听器”进行测试，您必须使用另一台机器。也就是说，您不能在同一 IP 上运行多个侦听器。

Create two applications, one represents the sender and the other the receiver.

Sender

Drop a TIdUDPClient and a TButton component on your form. On the OnClick handler of the button write:

procedure TfrmUDPClient.BroadcastClick(Sender: TObject);
begin
  UDPClient.Broadcast('Test', 8090);
end;

Receiver

Drop a TIdUDPServer on your form, define the same port (8090) for it and add this to the OnUDPRead handler:

procedure TfrmUDPServer.UDPServerUDPRead(Sender: TObject; AData: TStream; ABinding: TIdSocketHandle);
var
  DataStringStream: TStringStream;
  Msg: String;
begin
  DataStringStream := TStringStream.Create('');
  try
    DataStringStream.CopyFrom(AData, AData.Size);
    Msg := DataStringStream.DataString;
  finally
    DataStringStream.Free;
  end;
  ShowMessage(Msg);
end;

Or, in later versions of Indy:

procedure TfrmUDPServer.UDPServerUDPRead(AThread: TIdUDPListenerThread;
  const AData: TIdBytes; ABinding: TIdSocketHandle);
var
  Msg: String;
begin
  try
    {if you actually sent a string encoded in utf-8}
    Msg := TEncoding.UTF8.GetString(AData);
  except
  end;

  ShowMessage(Msg);
end;

To test, run both applications and click on the button. To test with two or more "listeners" you have to use another machine. That is, you can't run multiple listeners on the same IP.

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