如何从Js fetch()获取数据到服务器？

Question

I try to transfer data from js to the server, but I get "null".

My js:

async function sort(param) {
        let classList = param.classList;
                    //"DateCreate"     //Ascending
        console.log(param.id + " " + classList[0]);
       let response = await fetch("/Amendment/Sort", {
            method: "POST",
            body: JSON.stringify({ sortValue : param.id, sortType : classList[0]})
        });
        if (response.ok) {
            let responseHtml = await response.text();
            document.getElementsByClassName("result").innerHTML = responseHtml;
            alert("OK");
        } else {
            alert("Error HTTP: " + response.status);
        }

In browser:

Server's method (Controller: Amendment):

  [HttpPost]
                                    //null           //null
  public IActionResult Sort(string sortValue, string sortType )
  {
         //*****//
      return PartialView("_TableData", model);
  }

Answer 1

Solution 1:

You need to use the [FromBody] attribute as your request body contains sortValue and sortType .

Also make a class with sortValue and sortType string properties and in controller action method, use that class as parameter.

Soluttion 2:

Instead of putting sortValue and sortType in body, sending it from url.

var url = "/Amendment/Sort?sortValue=" + param.id + "&sortType=" + classList[0];
let response = await fetch(url, {
    method: "POST"
});

Answer 2

The problem resides in the way the framework binds the values you post to the parameters of this action method. If you define a class like the following one:

public class SortModel
{
    public string SortValue { get; set; }
    public string SortType { get; set; }
}

and then use this class as the only parameter of your action method then the framework will bind correctly the posted values.:

[HttpPost]
public IActionResult Sort(SortModel sortModel)
{
     // Then use 
     //   - sortModel.SortValue
     //   - sortModel.SortType
}

For further options, you can read this .