在 ReactJS 中使用 Fetch 调用 POST API 时出现错误 415

Question

I want to call an API for register from method in React. Below is my javascript code :

     fetch('http://localhost:5001/api/Account', {
        method: 'POST',
        headers: {
            'Content-Type': 'application/json',
        },
        body: JSON.stringify({
            email: "hugh.daniel@gmail.com",
            name: "Hugh Daniel",
            password: "1234"
        })
    })
    .then(function (response) {
        console.log(response);
    })
    .catch(function (error) {
        console.log(error);
    });

And this is my controller

    [HttpPost]
    public ResponseModel RegisterByEmail([FromBody]UserModel user)
    {
        return _accountService.RegisterEmail(user);
    }

But I always get these errors

I tried to add mode: 'no-cors' in my javascript code, but it makes Content-Type set to plain. The API is working if I tested it using Postman like this

Answer 1

You need to combat CORS first of all. You can't make API requests against a different domain:port than the one from which it was served by development server. Are you using Webpack in your project? If yes, the easiest way is to set up API proxy by the Webpack configuration. See the doc . Something like this:

// webpack.config.js
devServer: {
    port: 3030,
    proxy: {
      '/api': {
        target: `http://localhost:5001`,
        secure: false
      }
    }
  }

Now you have to remove host:port from fetch address param and also I would add Accept header to the request settings:

fetch('/api/Account', {
    method: 'post',
    headers: {
        'Accept': 'application/json',
        'Content-Type': 'application/json'
    },
    // ...
  }
)

Answer 2

Do not use JSON.stringify in the body for sending a request and following code will do the work.

fetch('http://localhost:5001/api/Account', {
    method: 'POST',
    headers: {
        'Content-Type': 'application/json',
    },
    body: {
        email: "hugh.daniel@gmail.com",
        name: "Hugh Daniel",
        password: "1234"
    }
})
.then(function (response) {
    console.log(response);
})
.catch(function (error) {
    console.log(error);
});

Answer 3

try this

[ApiController]
[Consumes("application/json")]
[Produces("application/json")]
[Route("[controller]")]        
public class TestController : ControllerBase
{}

In js:

await fetch(this.url, { method: 'POST', cache: 'no-cache', headers: { 'Content-Type': 'application/json' }, body: JSON.stringify(data) });

Sourse: https://pretagteam.com/question/angular-http-post-formdata-unsupported-media-type-from-c-controller