using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

public partial class upFile : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
this.img.Visible = false;
}
protected void btnUpFile_Click(object sender, EventArgs e)
{
string fullFileName = this.fileLoad.PostedFile.FileName;
string fileName = fullFileName.Substring(fullFileName.LastIndexOf("\\") + 1);
string typeFileName = fullFileName.Substring(fullFileName.LastIndexOf(".") + 1);
if (typeFileName == "jpg" || typeFileName == "gif" || typeFileName == "png")
{
this.fileLoad.SaveAs(Server.MapPath("upFiles") + "\\" + fileName);
this.img.ImageUrl = "upFiles/" + fileName;
this.img.Visible = true;
Response.Write ("上传成功");
}
else
{
Response.Write("");
}

}
}

可以实现简单的图片上传了，初学asp.net，写的不好，见笑了。