return 数组在 angular 4 中未定义

Question

我正在从 Web 服务获取数据并尝试在我的 service.web 服务 returns json 对象下使用 toPromise。

[
  {
    "username": "jack",
    "joinDate": "2017-10-28T00:00:00",
    "expireDate": "2017-10-31T00:00:00",
    "isActive": true,
    "userurl": "https://dummy.com",
    "masterkey": "77uyerue987930000",
    "appkey": "hdhfjd98984300000",
    "id": 49
  },
  {
    "username": "paul",
    "joinDate": "2017-10-28T00:00:00",
    "expireDate": "2017-10-31T00:00:00",
    "isActive": true,
    "userurl": "https://dummy.com",
    "masterkey": "98dfdf88",
    "appkey": "89fdf98",
    "id": 49
  }
]

then here is my method to consume response from web service :

returntestData() {


const url:string = 'https://userportal/api/company';
this.nhttp.get(url)
      .toPromise()
      .then(res => <Users[]> res.json().data)
      .then(
        data => {
          console.log(data)
          return data
        }
      );
  }

所以数据总是未定义的。那么我不能在我的组件中使用它。

in other hand I tried below

getallCompanies(): Users[] {

let UsersDetails: Users[] = [];

const url:string = 'https://userportal/api/company';

this.http.get<[{Users}]>(url).subscribe(
  data => {
     for(var i=0;i<data.length;i++) {
      let newuser = new Companies(data[i]["username"],data[i]["id"],data[i]["isActive"],data[i]["joinDate"],data[i]["expireDate"],data[i]["appkey"],data[i]["masterkey"],data[i]["userurl"]);
      UsersDetails.push(newuser);
     }
     console.log("full data from service : "+ UsersDetails);
     return UsersDetails;

  },
  err => {
    console.log("error occured while calling to web service");
    console.log(err)
  }
);

return UsersDetails;


 }

以上代码 returns 值正确。但它 returns 查看 loaded.not 一个 async 调用后的值。希望您对此有所帮助。

Answer 1

如果您使用新的 HttpClient，则没有 res.json 方法。它会自动工作，只需像这样传递响应类型：

returntestData() {
    const url:string = 'https://userportal/api/company';

    return this.http.get<Users[]>(url)
        .toPromise()
        .then(data => {
            console.log(data)
            return data
        });
}

还取决于接口Users。

return 数组在 angular 4 中未定义

return array is undefined in angular 4

angular

web-services

http

asynchronous

angular-httpclient