Angular HttpClient post 无法发送简单的字符串参数

Question

我想向以字符串作为参数的 C# 服务发送请求。我写了一个这样的 angular 服务：

export class CategoryService {

  constructor(private http: HttpClient) { }
  getCategory(categoryName: string): Observable<Category> {
    console.log(categoryName);
    return this.http.post("/category/GetCategory", { categoryName: categoryName }, { headers: new HttpHeaders({ 'Content-type': 'application/json' }) });
  }

我也试过：

export class CategoryService {

  constructor(private http: HttpClient) { }
  getCategory(categoryName: string): Observable<Category> {
    console.log(categoryName);
    return this.http.post("/category/GetCategory",  categoryName , { headers: new HttpHeaders({ 'Content-type': 'application/json' }) });
  }

但是当他们都成功发送请求时，参数始终为null。我的 C# 服务是：

    [HttpPost]
    public IActionResult GetCategory([FromBody]string categoryName)

Answer 1

我在这里找到了解决方案：我还应该从我的服务参数中删除 [FromBody]。

Answer 2

我可以提供我自己的解决方案:)
Angular:

Func(data: string): Observable<any> {
        let params = new HttpParams();
        params = params.set('data', data);
        return this.http.post("url", params);
    }

C#:

public IActionResult Method([FromForm]string data)

Answer 3

Best and easiest solution

this.http.post(this.serverAddress + API_ADDRESS + '?param=' + yourStringParam, null);

Answer 4

正如@Niladri 所说，这对我有用：

... using JSON.stringify(categoryName) in your typescript service with FromBody in controller

这也很重要：

... keep the content-type as HttpHeaders({ 'Content-Type': 'application/json' })

它与控制器方法中的 FromBody 一起工作:)

Angular HttpClient post 无法发送简单的字符串参数

Angular HttpClient post cannot send simple string parameter

javascript

c#

http-post

angular