C#中att = (OpenPOP.MIMEParser.Attachment)msg.Attachments[1]; 中最后面中括号里的1是什么意思？

[huahua_asic]

c#编写的邮件接收中
OpenPOP.MIMEParser.Attachment att = null;
OpenPOP.MIMEParser.Message msg = null;
att = (OpenPOP.MIMEParser.Attachment)msg.Attachments[1];
其中第三句中最后面中括号的1代表的是什么意思？为什么不是0？
我想知道为什么不是0，这个数组里面有几个元素我也不清楚 因为我在运行的时候出错了 有个索引越界了 我不确定是不是这里
请各位高手指点~~~万分感激~

[dqw120]

string f="";
//string strf="";
jmail.Message Msg=new jmail.Message();
jmail.POP3 jpop=new jmail.POP3();
try
{
jpop.Connect("shaokang99","4226521","pop3.163.com",110);
Count.Text=jpop.Count.ToString();
Msg = jpop.Messages[3];
Sendfrom.Text = Msg.FromName;
Subject.Text = Msg.Subject;
Datetime.Text = Msg.Date.ToString();
Body.Text = Msg.Body;
num.Text=Msg.Attachments.Count.ToString();
for(int i=0;i<Msg.Attachments.Count;i++)
{
f=f+Msg.Attachments[i].Name;
Msg.Attachments[i].SaveToFile("e:\\"+Msg.Attachments[i].Name);



}
name.Text=f;
jpop.Disconnect();
}
catch(Exception ex)
{
Count.Text=ex.Message.ToString();
}

[dqw120]

定义一个n,int n=1 or 2......;n是表示是第几封信，你可以用jpop.Count来循环取出所有的

Msg = jpop.Messages[3];--->Msg = jpop.Messages[n];

Msg.Attachments[i].SaveToFile("e:\\"+Msg.Attachments[i].Name);---->
Msg.Attachments[i].SaveToFile("e:\\"+Msg.Attachments[n].Name);