页面：
<body> <form > <table> <tr> <td>图片：</td> <td><input type="file" name="file" accept="image/*" value="选择" /></td> </tr> </table> <input type="submit" value="上传" /> </form> </body>
后台：
public string Upload()
{
HttpPostedFileBase file = Request.Files["file"];
if (file.ContentLength > 0)
{
string savePath = Server.MapPath("~/Uploads/Pictures");
string failPath = savePath + "\\" + file.FileName;
file.SaveAs(failPath);
return “图片上传成功！”;
}
else
{
return "未选择图片！";
}
}