一个错误，不知道是什么意思？ 请高手赐教！

[历史可以倒流]

我在用NMUDP 组件 进行数据的传递时，遇到了一个 List Index out of bounds(0) 的错误！ 请问这是什么类型的错误啊？ 应该怎么改啊！ 还有我改ServerSocket 和ClientSocket 时也是如此，不知什么原因。

[yxf]

List Index out of bounds(0) ：
用到了字符串列表这一类的吧？索引超出原有存在的。

[历史可以倒流]

怎样跟踪啊！ 我还是个初级者，不知道怎样跟踪啊！ 其中Unit1代码是这样的：
unit Unit1;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, ComCtrls, StdCtrls, NMUDP;

type
TForm1 = class(TForm)
NMUDP1: TNMUDP;
Label1: TLabel;
Edit1: TEdit;
Label2: TLabel;
Edit2: TEdit;
Button1: TButton;
StatusBar1: TStatusBar;
procedure Button1Click(Sender: TObject);
procedure NMUDP1Status(Sender: TComponent; status: String);
procedure NMUDP1DataSend(Sender: TObject);
procedure NMUDP1DataReceived(Sender: TComponent; NumberBytes: Integer;
FromIP: String; Port: Integer);
procedure NMUDP1InvalidHost(var handled: Boolean);
procedure Edit1Change(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;

var
Form1: TForm1;

implementation
uses unit2;
{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
begin
Form2.Show;
end;

procedure TForm1.NMUDP1Status(Sender: TComponent; status: String);
begin
Statusbar1.Panels[0].Text :='Status: '+status;
end;

procedure TForm1.NMUDP1DataSend(Sender: TObject);
begin
Statusbar1.Panels[0].Text :='Status: Message Sent';
end;

procedure TForm1.NMUDP1DataReceived(Sender: TComponent;
NumberBytes: Integer; FromIP: String; Port: Integer);
var
mStream:TMemoryStream;
strData:String;
begin
mStream:=TMemoryStream.Create ;
try
NMUDP1.ReadStream(mStream);
SetLength(strData,NumberBytes);
mStream.Read(strData[1],NumberBytes);
edit2.Text :=strData;
finally
mStream.Free ;
end;
end;

procedure TForm1.NMUDP1InvalidHost(var handled: Boolean);
begin
MessageDlg('Remote Host: '+NMUDP1.RemoteHost +'is invalid',mtError,[mbOk],0);
end;

procedure TForm1.Edit1Change(Sender: TObject);
var
mStream:TMemoryStream;
strData:String;
begin
NMUDP1.ReportLevel:=Status_Basic;
NMUDP1.RemoteHost :='127.0.0.1';
strData:=edit1.Text ;
mStream:=TMemoryStream.Create ;
try
mStream.Write(strData,Length(strData));
NMUDP1.SendStream (mStream);
finally
mStream.Free;
end;
end;

end.

[netfyee]

up

[beata88]

那是索引越界的问题！
你跟踪一下看是什么地方越界了