Angular http.post，没有得到响应，总是得到响应为 null

Question

Angular Http.post，有一个 post call，我发送 jsonData 作为具有以下格式数据的参数，但每次我得到响应为 null，请问我的代码有什么错误吗？ 如果有请帮忙。 这是我尝试过的示例代码，

let jsondataItems :any =[];

var jsonData = [
    {
        "empId": 11234,
        "salary": "98763",
        "test1id": "9897989",
        "test2id": "657453",
        "test3id": "4456",
        "month": "AUG-19"
    }]

this.http
      .post<empData>(url, jsonData)
      .subscribe((res) => {
        this.jsondataItems = res;
        console.log("res" + this.jsondataItems); // getting null
        console.log("res" + JSON.stringify(this.jsondataItems)); //getting null
        console.log("Processed successfully!!!"); // getting console -- working
      });
  }



interface empData {
  empId: number; //1234
  salary: string; //"3456"
  test1id: string; //""5678"
  test2id:string; //"5643"
  test3id:string; // "4533"
  month: string; //"JAN-20"
}

Answer 1

尝试以下操作：

 import { HttpHeaders } from '@angular/common/http';
        
        const httpOptions = {
          headers: new HttpHeaders({
            'Content-Type':  'application/json'
          })
        };
   
    let jsondataItems :any =[];
    
    var jsonData = [
        {
            "empId": 11234,
            "salary": "98763",
            "test1id": "9897989",
            "test2id": "657453",
            "test3id": "4456",
            "month": "AUG-19"
        }]
    
    this.http
          .post<empData>(url, jsonData,httpOptions)
          .subscribe((res) => {
            this.jsondataItems = res;
            console.log("res" + this.jsondataItems);
            console.log("res" + JSON.stringify(this.jsondataItems));
            console.log("Processed successfully!!!"); 
          });
      }
    
    
    
    interface empData {
      empId: number;
      salary: string; 
      test1id: string; 
      test2id:string; 
      test3id:string; 
      month: string; 
    }

您可以采用与您相同的 http 选项，但添加观察：响应。 header 是来自 http 客户端的 HttpHeaders。 例如：标头：新的 HttpHeaders().set('Content-Type', 'application/x-www-form-urlencoded'),