Format JSON response using ASP.NET JsonResult Class

Question

I'm trying to integrate BlueImp jQuery file upload component into my ASP.NET 4 website. I have the file upload working and writing to disk, but the component requires that I return a JSON object from the server as confirmation of success, in a particular format:

{"files": [
  {
    "name": "picture1.jpg",
    "size": 902604,
    "url": "http:\/\/example.org\/files\/picture1.jpg",
    "thumbnailUrl": "http:\/\/example.org\/files\/thumbnail\/picture1.jpg",
    "deleteUrl": "http:\/\/example.org\/files\/picture1.jpg",
    "deleteType": "DELETE"
  },
  {
    "name": "picture2.jpg",
    "size": 841946,
    "url": "http:\/\/example.org\/files\/picture2.jpg",
    "thumbnailUrl": "http:\/\/example.org\/files\/thumbnail\/picture2.jpg",
    "deleteUrl": "http:\/\/example.org\/files\/picture2.jpg",
    "deleteType": "DELETE"
  }
]}

I'd like to use the JsonResultClass to return this object in my C#, but I'm not sure how to format the response correctly. I can probably do something like this:

var uploadedFiles = new List<object>();

uploadedFiles.Add(new { name = "picture1.jpg", size = 902604, url = "http://example.org/files/picture1.jpg", thumbnailUrl = "http://example.org/files/thumbnail/picture1.jpg", deleteUrl ="http://example.org/files/picture1.jpg", deleteType = "DELETE" });
uploadedFiles.Add(new { name = "picture2.jpg", size = 902604, url = "http://example.org/files/picture1.jpg", thumbnailUrl = "http://example.org/files/thumbnail/picture1.jpg", deleteUrl ="http://example.org/files/picture1.jpg", deleteType = "DELETE" });

return Json(uploadedFiles);

...but then I'm not sure how to wrap this in the outer 'files' object.

Can anyone point me (a .NET novice trying to learn!) in the right direction here. I've looked at the MSDN documentation but it doesn't go into detail about formatting or constructing more complex JSON objects.

Many thanks.

Answer 1

Replace:

return Json(uploadedFiles);

with:

return Json(new {files = uploadedFiles});

to create a new anonymous type with property "files", which has your original list as a value.