谁用过TUdpSocket吗?

Question

现在需要用写一个接收UDP包的服务端.用TUdpSocket以后老是接收不到数据,是因为什么啊?请指教一下.或者用别的什么也可以

Answer 1

1.检查一下你的UDPSOCKET,是否正确地初始化并已经监听UDP端口
2.检查一下你的UDP发送端,是否正确地发送数据;像网络传输的调试,都要双向检查的,一边检查完,便排除,再检查另一边

Answer 2

unit Unit_UDP;interfaceuses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, IdBaseComponent, IdComponent, IdUDPBase, IdUDPServer,IdSocketHandle,
  IdAntiFreezeBase, IdAntiFreeze, Gauges, StdCtrls, IdUDPClient;type
  TForm_UDP = class(TForm)
    IdUDPServer1: TIdUDPServer;
    grp1: TGroupBox;
    grp2: TGroupBox;
    mmo1: TMemo;
    edt1: TEdit;
    lbl1: TLabel;
    btn1: TButton;
    IdUDPClient1: TIdUDPClient;
    Label1: TLabel;
    Label2: TLabel;
    lbl2: TLabel;
    edt4: TEdit;
    Button1: TButton;
    edt2: TEdit;
    edt3: TEdit;
    edt5: TEdit;
    lbl3: TLabel;
    procedure IdUDPServer1UDPRead(Sender: TObject; AData: TStream;ABinding: TIdSocketHandle);
    procedure btn1Click(Sender: TObject);
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;var
  Form_UDP: TForm_UDP;implementation{$R *.dfm}procedure TForm_UDP.IdUDPServer1UDPRead(Sender: TObject; AData: TStream;
  ABinding: TIdSocketHandle);
Var
  Str:String;
begin
  AData.Seek(0,0);
  SetLength(Str,AData.Size);
  AData.Read(Str[1],AData.Size);
  mmo1.Lines.Add(str);
  str:= 'message has received';
  ABinding.SendTo(ABinding.PeerIP, ABinding.PeerPort,Str[1] , Length(Str));
end;procedure TForm_UDP.btn1Click(Sender: TObject);
begin
  IdUDPServer1.DefaultPort:=StrToInt(edt1.Text);
  IdUDPServer1.Active:=True;
end;procedure TForm_UDP.Button1Click(Sender: TObject);
Var
  ReceivedString:String;
begin
    IdUDPClient1.Host:=edt2.Text;
    IdUDPClient1.Port:=StrToInt(edt3.Text);
    IdUDPClient1.Active:=True;
    IdUDPClient1.Send(edt4.text);
    ReceivedString := IdUDPClient1.ReceiveString();
    edt5.Text:=ReceivedString;
end;end.