Jun Jun - 1 year ago 255
ASP.NET (C#) Question

ASP.NET web api cannot get application/x-www-form-urlencoded HTTP POST

I'm new to web-api. I want to receive a HTTP POST data using web-api. The content-type is

, and the request body is like:

(JSON format).

My controller is like this:

public void Post([FromBody]string formData)

But formData is always null. Only when I change the request body to:


I can find
was saved in my

So my question is how should I receive the data with format:


And is there a easy way that I can desalinize the JSON into C#?

Thanks for help!

I tried to use model, but it still not work for me.
My model is:

public class Device
public string mac { get; set; }
public string model { get; set; }

and my HTTP POST request is:


User-Agent: Fiddler
Content-type: application/x-www-form-urlencoded
Host: localhost:52154
Content-Length: 46



I have to use
Content-type: application/x-www-form-urlencoded
as far as I know because the HTTP POST is sent by a router. My job is to receive the data.

Answer Source

Quoting from here:

By default, Web API tries to get simple types from the request URI. The FromBody attribute tells Web API to read the value from the request body.

Web API reads the response body at most once, so only one parameter of an action can come from the request body. If you need to get multiple values from the request body, define a complex type.

Second, the client needs to send the value with the following format:


Specifically, the name portion of the name/value pair must be empty for a simple type.

So, if you want to post data in the format data=string, you have to create complex type.

public class MyFormData
    public string Data { get; set; }

And update your controller like so:

public void Post(MyFormData formData)
    //your JSON string will be in formData.Data

Of course, other alternatives for you is to change the content type to JSON, but really depends on your requirements.