无法使用C＃从asp.net的客户端接收文件

Question

I'm trying to get a profile image from a form. The html looks like this:

<form action="UpdateProfile.aspx" method="post">
  <input type='file' name='profilePic'/>
</form>

The server side code looks like this:

HttpPostedFile image = Request.Files["profilePic"];
string imagePath = @"../Pictures/Profile/DefaultPicture.png";
if (image.ContentLength >0 && image != null)
{
   if (Path.GetExtension(image.FileName) == "jpg" || Path.GetExtension(image.FileName) == "jpeg" ||
       Path.GetExtension(image.FileName) == "png" || Path.GetExtension(image.FileName) == "gif" ||
       Path.GetExtension(image.FileName) == "bmp")
   {
       string fileExtention = Path.GetExtension(image.FileName);
       string FileName = Session["Username"].ToString() + "." + fileExtention;
       image.SaveAs(Server.MapPath(Path.Combine("../Pictures/Profile/", FileName)));
       imagePath = Path.Combine("../Pictures/Profile/", FileName);
   }
}

But it never works, no matter what I upload the image variable is always null . its like the server cant recive it or something. can you guys help me solve it or tell me where i went wrong? Thank you in advance.

Answer 1

Be sure that you set the Content-Type correctly:

The file collection is populated only when the HTTP request Content-Type value is "multipart/form-data".

https://msdn.microsoft.com/en-us/library/system.web.httprequest.files%28v=vs.110%29.aspx

Here is an example:

<FORM action="..."
       enctype="multipart/form-data"
       method="post">
   ...
</FORM>

Answer 2

An example to guide you.

 <asp:FileUpload ID="FileUpload1" runat="server" />
 <asp:Button ID="btnUpload" runat="server" Text="Upload" OnClick="Upload" />

 using System.IO;
 using System.Collections.Generic;
 protected void Upload(object sender, EventArgs e)
 {
    if (FileUpload1.HasFile)
    {
    string fileName = Path.GetFileName(FileUpload1.PostedFile.FileName);
    FileUpload1.PostedFile.SaveAs(Server.MapPath("~/Images/") + fileName);
    Response.Redirect(Request.Url.AbsoluteUri);
   }
 }