请问这段asp.net的代码是什么意思，请说得祥细一点，我是初学者，谢谢

Question

DataTable dt = new DataTable();
dt.Columns.Add(new DataColumn("Name", typeof(string)));
string serverPath = Server.MapPath("File");
DirectoryInfo dir = new DirectoryInfo(serverPath);
foreach (FileInfo fileName in dir.GetFiles())
{
DataRow dr = dt.NewRow();
dr[0] = fileName;
dt.Rows.Add(dr);
}
ListBox1.DataSource = dt;
ListBox1.DataTextField = "Name";
ListBox1.DataValueField = "Name";
ListBox1.DataBind();
}

string path = Server.MapPath("File/") + Session["txt"].ToString();
FileInfo fi = new FileInfo(path);
if (fi.Exists)
{
Response.AddHeader("Content-Disposition", "attachment;filename=" +Server.HtmlDecode( fi.Name));

}

Answer 1

DataTable dt = new DataTable(); ---新建一个table
dt.Columns.Add(new DataColumn("Name", typeof(string)));--新增一个列为name string类型
string serverPath = Server.MapPath("File");
DirectoryInfo dir = new DirectoryInfo(serverPath);---找到文件路径的所有文件
foreach (FileInfo fileName in dir.GetFiles())
{
DataRow dr = dt.NewRow();
dr[0] = fileName;
dt.Rows.Add(dr);
}---遍历文件名称 存入到table中的name属性中
ListBox1.DataSource = dt;
ListBox1.DataTextField = "Name";
ListBox1.DataValueField = "Name";
ListBox1.DataBind();---给listbox绑定table的数据
}

string path = Server.MapPath("File/") + Session["txt"].ToString();
FileInfo fi = new FileInfo(path);
if (fi.Exists)
{
Response.AddHeader("Content-Disposition", "attachment;filename=" +Server.HtmlDecode( fi.Name));

}---生成下载文件