C# generic handler not getting data from post

Question

I'm doing a simple c# generic handler that should receive a form post. Here's the form...

<form id="frmUploadImage" action="../Handlers/LocalImageUploadHandler.ashx" method="post" style="display: none">
    <div>
        <input style="display: none; margin-bottom: 20px" type="file" id="uploadImage" />
    </div>
</form>

I have some code that, upon the click of a button invokes the click event of the input. When the input is loaded, the following is invoked (I can set a breakpoint and it gets here).

var jqxhr = $.post('../Handlers/LocalImageUploadHandler.ashx', $('#frmUploadImage').serialize())
            .success(function() {
                alert('worked');
            })
            .error(function() {
                alert('failed');
            });

It will show an alert for "failed". Server-side, it is calling this in the handler (I can verify that it is getting invoked by setting a breakpoint).

public void ProcessRequest(HttpContext context)
    {
        context.Response.ContentType = "application/octet-stream";
        var file = Convert.FromBase64String(context.Request.Form["uploadedFile"]);
//other stuff
}

What's interesting is that the context.Request.Form and context.Request.Files properties have no items in them, even though they are being sent. Nothing I've done has worked. I've tried posting with XHR, jQuery, etc. I've tried pulling the data out of the file upload control as a DataUrl and serializing it to a base64 encoded string and putting it in an ajax call. The handler will receive a post, but the data is being stripped.

You may need to give your input element a `name` attribute. – Gabriel Luci Nov 01 '16 at 19:50 — Gabriel Luci, Nov 01 '16 at 19:50

Rajshee Turakhia · Answer 1 · 2016-11-02T12:05:30.377

You need to tryout following code to make it working User Side Code $('#btnUpload').click(function () {

var fileUpload = $("#FileUpload1").get(0);
var files = fileUpload.files;
var test = new FormData();
for (var i = 0; i < files.length; i++) {
test.append(files[i].name, files[i]);
}
$.ajax({
url: "LocalImageUploadHandler.ashx",
type: "POST",
contentType: false,
processData: false,
data: test,
// dataType: "json",
success: function (result) {
alert(result);
},
error: function (err) {
alert(err.statusText);
}
});
});

Server Side Code

public void ProcessRequest (HttpContext context) {
if (context.Request.Files.Count > 0)
{
HttpFileCollection files = context.Request.Files;
for (int i = 0; i < files.Count; i++)
{
HttpPostedFile file = files[i];
string fname;
if (HttpContext.Current.Request.Browser.Browser.ToUpper() == "IE" || HttpContext.Current.Request.Browser.Browser.ToUpper() == "INTERNETEXPLORER")
{
string[] testfiles = file.FileName.Split(new char[] { '\\' });
fname = testfiles[testfiles.Length - 1];
}
else
{
fname = file.FileName;
}
fname=Path.Combine(context.Server.MapPath("~/uploads/"), fname);
file.SaveAs(fname);
}
}
context.Response.ContentType = "text/plain";
context.Response.Write("File Uploaded Successfully!");
}
public bool IsReusable {
get {
return false;
}
}

C# generic handler not getting data from post

1 Answers1