File1.PostedFile.SaveAs(uploadPath + fileName);未将对象引用设置到对象的实例

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Collections;
using System.Web.UI.HtmlControls;

namespace HtmlInputFile
{
    public partial class Default : System.Web.UI.Page
    {
        
        protected void Page_Load(object sender, EventArgs e)
        {
            this.Button1.ServerClick+=new EventHandler(Button1_OnClick);
        }
        protected void Button1_OnClick(object sender, EventArgs e)
        {
            ArrayList arrayList = new ArrayList();
            arrayList.AddRange(File1.Value.Split('\\'));
            string fileName = arrayList[arrayList.Count - 1].ToString();
            string uploadPath = Page.Request.PhysicalApplicationPath + "UpLoadFile\\";
            try
            {

                File1.PostedFile.SaveAs(uploadPath + fileName);
                Response.Write("文件上传成功！");
            }
            catch (Exception ex)
            {
                Response.Write(ex.Message);
            }
            
        }
    }
} --------------------编程问答--------------------  <form id="form1" runat="server" method="post" enctype="multipart/form-data">
--------------------编程问答-------------------- 另外，FileUpload控件就是很方便的啊 --------------------编程问答-------------------- 参考

补充：.NET技术 ,  ASP.NET