post in httpclient?

post in httpclient?

 let url = "http://@" + this.sRouterIP + "/config_macfilter_app.php";
  let mac:string=("1c:b0:94:ae:0e:1f").toLocaleUpperCase();
  let s_body=JSON.stringify({body:"action=app_block&interface=wifi0&mac=" + encodeURIComponent(mac)}) 
  

  let formdata = new FormData();
  formdata.append("body", s_body)

  let requestOptions: Object = { 
    //headers: new HttpHeaders().set('Content-Type','application/x-www-form-urlencoded')//not works
    headers: new HttpHeaders().set('Content-Type','application/json'),//not works
    responseType: 'text'
  }   

  this.http.post(url,formdata,requestOptions).subscribe((res:any)=>{//put formdata nor s_body object is not working 
    console.log(res)
  })
  
  /////////////////////////WORKS XMLHTTPREQUEST
  
     let sIP = this.sRouterIP;
    let url = "http://@" + sIP + "/config_macfilter_app.php";
    let sBody = "action=app_block&interface=wifi0&mac=" + encodeURIComponent(mac);
    let request = new XMLHttpRequest();
    request.open("POST", url,true);
    //request.timeout = 30000;
    request.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
    request.onreadystatechange = () => {
     
      if (request.readyState == 4 && request.status == 200) {
       
        if (!this.ValidateResponseText(request.responseText)) {
          this.LoadingFailed();
          this.CheckConnection();
        }
      }
    }
    request.send(sBody);
  
  

Try to use simply this body :let body = "action=app_block&interface=wifi0&mac=" + encodeURIComponent(mac)" and don't use FormData().

Use this body on your httpClient request : this.http.post(url,body,requestOptions).subscribe((res:any)=>{ console.log(res) })