ASP.NET Upload file return its content - asp.net

Question

I'm trying to upload a file then retrieve its content as JSon
My controller :
controller.cs
[HttpPost]
public JsonResult Upload(HttpPostedFileBase file)
{
List<string> list = doStuff(file);
return Json(list);
}
My view :
view.cshtml
#using (Html.BeginForm("Upload", "Files", FormMethod.Post, new { enctype = "multipart/form-data" }))
{
<input type="file" id="file" name="file" />
<input type="submit" name="Upload" value="Upload" />
}
When I upload a file it propose me to download a JSON file, but what I want is to set a javascript variable with this JSON so I can use it directly on my webpage.

Answer 1

I believe that the best solution is to use an ajax form.
See the example below:
Controller:
[HttpPost]
public JsonResult Upload(HttpPostedFileBase file)
{
return Json(new { ReturnMessage = "Success!!!!!" + file.FileName});
}
View:
#using (Html.BeginForm("Upload", "Home", FormMethod.Post, new { #id="formUploadFile", #onsubmit = "return SubmitFormWithFile();" }))
{
#Html.TextBox("file", null, new { #type = "file", #id = "file" })
<button type="submit">Send</button>
}
Javascript:
function SubmitFormWithFile() {
var form = $("#formUploadFile");
$.ajax({
url: form.attr("action"),
type: form.attr("method"),
data: new FormData(form[0]),
cache: false,
contentType: false,
processData: false,
beforeSend: function () {
alert("Before Send");
},
success: function (dataResult) {
//set its variable here...
//the dataResult is returned json...
alert(dataResult.ReturnMessage);
},
error: function () {
alert("Error");
}
});
return false;
}