Post json data in body to web api

问题:

I get always null value from body why ? I have no problem with using fiddler but postman is fail.

I have a web api like that:

    [Route("api/account/GetToken/")]
    [System.Web.Http.HttpPost]
    public HttpResponseBody GetToken([FromBody] string value)
    {
        string result = value;
    }

My postman data:

and header:

回答1:

WebAPI is working as expected because you're telling it that you're sending this json object:

{ "username":"admin", "password":"admin" }

Then you're asking it to deserialize it as a string which is impossible since it's not a valid JSON string.

Solution 1:

If you want to receive the actual JSON as in the value of value will be:

value = "{ \"username\":\"admin\", \"password\":\"admin\" }"

then the string you need to set the body of the request in postman to is:

"{ \"username\":\"admin\", \"password\":\"admin\" }"

Solution 2 (I'm assuming this is what you want):

Create a C# object that matches the JSON so that WebAPI can deserialize it properly.

First create a class that matches your JSON:

public class Credentials
{
    [JsonProperty("username")]
    public string Username { get; set; }

    [JsonProperty("password")]
    public string Password { get; set; }
}

Then in your method use this:

[Route("api/account/GetToken/")]
[System.Web.Http.HttpPost]
public HttpResponseBody GetToken([FromBody] Credentials credentials)
{
    string username = credentials.Username;
    string password = credentials.Password;
}

回答2:

You are posting an object and trying to bind it to a string. Instead, create a type to represent that data:

public class Credentials
{
    public string Username { get; set; }
    public string Password { get; set; }
}

[Route("api/account/GetToken/")]
[System.Web.Http.HttpPost]
public HttpResponseBody GetToken([FromBody] Credentials value)
{
    string result = value.Username;
}