Question

我有两个请求GET和POST请求，我正在获取GET请求并在和array内设置响应状态，我想将此数组传递给POST请求主体，然后获取POST请求所以我可以打电话，问题是它没有在GET呼叫中设置状态，并且总是返回undefined，我不知道为什么，这里是代码：

我的构造函数：

constructor(props){
  super(props);
  this.state = {
    info: [],
  }
}

功能

：

myFunction = async () => {
  fetch("https://myapp.com/info", {
    method: "GET",
    headers: {
      "Content-Type": "application/json",
      "x-auth-token": token
    }
  })
    .then(res => res.json())
    .then(response => {
      this.setState({ info: response });
      fetch("https://myapp.com/submit_info", {
        method: "POST",
        headers: {
          "Content-Type": "application/json",
          "x-auth-token": token
        },
        body: JSON.stringify({
          infoID: this.state.info.id
        })
      })
        .then(res => res.json())
        .then(result => {
          console.log(result);
        });
    })
    .catch(error => console.log(error));
};

Answer 1

您忘记了返回承诺，然后使用response对象来设置infoID字段，而不是状态导致对this.setState的调用是异步的，并且当您进行第二次api调用。

myFunction = () => {
  fetch("https://myapp.com/info", {
    method: "GET",
    headers: {
      "Content-Type": "application/json",
      "x-auth-token": token
    }
  })
    .then(res => res.json())
    .then(response => {
      this.setState({ info: response }); // async call
      return fetch("https://myapp.com/submit_info", {
        // return promise for chaining
        method: "POST",
        headers: {
          "Content-Type": "application/json",
          "x-auth-token": token
        },
        body: JSON.stringify({
          infoID: response.id
        })
      })
        .then(res => res.json())
        .then(result => {
          console.log(result);
        });
    })
    .catch(error => console.log(error));
};

在同一函数中进行两次调用

1 个答案: