How to get form data from Postman To WebApi

Question

I want to receive form data from Postman:

Content-Type: application/json

Here is WebApi method:

[HttpPost]
[Route("api/test")]
public async Task TestMethod(HttpRequestMessage request)
{
    var test = await request.Content.ReadAsStringAsync();
}

What I'm getting is:

------WebKitFormBoundarypqDvmeG89cBR9mK9
Content-Disposition: form-data; name="test"

esad
------WebKitFormBoundarypqDvmeG89cBR9mK9--

But I don't want data with WebKitFormBoundary and I've restriction to use formdata only. Is there any other way?

HTTP call information:

POST /api/test HTTP/1.1
Host: localhost:16854
Content-Type: multipart/form-data; boundary=----WebKitFormBoundary7MA4YWxkTrZu0gW
Cache-Control: no-cache
Postman-Token: 1a3d6427-4956-707d-da0c-3a29a63c7563

------WebKitFormBoundary7MA4YWxkTrZu0gW
Content-Disposition: form-data; name="test"

esad
------WebKitFormBoundary7MA4YWxkTrZu0gW--

Curl call information:

curl -X POST \
  http://localhost:16854/api/test \
  -H 'cache-control: no-cache' \
  -H 'content-type: multipart/form-data; boundary=----WebKitFormBoundary7MA4YWxkTrZu0gW' \
  -H 'postman-token: 02055873-e9a8-e9a6-019c-b407992b0e2f' \
  -F test=esad 

Answer 1

1) If you have to send Content-Type: multipart/form-data OR simply form-data

This is the first tab of Postman

If you have to collect only one key/value pair of your posted form-data

[HttpPost]
[Route("api/test")]
public HttpResponseMessage TestMethod(HttpRequestMessage request)
{
    var testValue = HttpContext.Current.Request.Form["test"];

    return Request.CreateResponse(HttpStatusCode.OK, testValue);
}

If you have to collect more than one key/value pair of your posted form-data

[HttpPost]
[Route("api/test")]
public HttpResponseMessage TestMethod(HttpRequestMessage request)
{
    NameValueCollection collection = HttpContext.Current.Request.Form;

    var items = collection.AllKeys.SelectMany(collection.GetValues, (k, v) => new { key = k, value = v });

    //We just collect your multiple form data key/value pair in this dictinary
    //The following code will be replaced by yours
    Dictionary<string, string> keyValuePairs = new Dictionary<string, string>();

    foreach (var item in items)
    {
        keyValuePairs.Add(item.key, item.value);
    }

    return Request.CreateResponse(HttpStatusCode.OK, keyValuePairs);
}

---

2) If you have to send Content-Type: application/x-www-form-urlencoded

This is the second tab of Postman

Then your API will be

[HttpPost]
[Route("api/test")]
public async Task TestMethod(HttpRequestMessage request)
{
    var test = await request.Content.ReadAsFormDataAsync();
}

Then you will get following output when you debug your code with breakpoint

---

3) If you have to send Content-Type: application/json

This is the third tab of Postman

See below screenshot for such option

And your api is

[HttpPost]
[Route("api/test")]
public async Task TestMethod(HttpRequestMessage request)
{
     var jObject = await request.Content.ReadAsAsync<JObject>();

     Item item = JsonConvert.DeserializeObject<Item>(jObject.ToString());
}

And your model to collect this posted data

public class Item
{
    public string test { get; set; }
}

And your output will be

The advantage of this option you can send complex type as posted data and like

And your api is

[HttpPost]
[Route("test")]
public async Task TestMethod(HttpRequestMessage request)
{
    var jObject = await request.Content.ReadAsAsync<JObject>();

    Sample sample = JsonConvert.DeserializeObject<Sample>(jObject.ToString());
}

And you model to collect this data are

public class Item
{
    public string test { get; set; }
}

public class Sample
{
    public Item item { get; set; }
}

And you will see the output is

Answer 2

The following code will read key/value correctly when sent from Postman with form-data option selected

[HttpPost]
[Route("api/test")]
public async Task<HttpResponseMessage> TestMethod(HttpRequestMessage request)
{
    string root = HttpContext.Current.Server.MapPath("~/App_Data");
    var provider = new MultipartFormDataStreamProvider(root);

    await Request.Content.ReadAsMultipartAsync(provider);

    var testValue = provider.FormData.GetValues("test")[0];

    return Request.CreateResponse(HttpStatusCode.OK);
}

A more thorough example can be found here (Section: Reading Form Control Data).

Edit: The HTTP call that is sent to the above API handler is the one below:

POST /api/stats/testmethod HTTP/1.1
Host: localhost:4100
Cache-Control: no-cache
Postman-Token: 999fd13d-f804-4a63-b4df-989b660bcbc5
Content-Type: multipart/form-data; boundary=----WebKitFormBoundary7MA4YWxkTrZu0gW

------WebKitFormBoundary7MA4YWxkTrZu0gW
Content-Disposition: form-data; name="test"

esad
------WebKitFormBoundary7MA4YWxkTrZu0gW--