javascript - undefined 不是对象 react-native

Question

我在为获取 API 响应的数据设置状态时遇到问题

render() {
    function getCode(text) {
      fetch('url', {
        method: 'POST',
        headers: {
          Accept: 'application/json',
          'Content-Type': 'application/json'
        },
        body: JSON.stringify({
          "telephone": text, 
          "password": "123123"
        })
      }).then(response => response.json())
      .then(response => {
        console.log(this.state.text)
        console.log(this.state.uid)

        this.setState({uid : response["data"]["telephone"]})
        console.log(this.state.uid)
      // this.setState({uid: response["data"]["telephone"]})
      // console.log(this.state.uid); 
    })
  }

这是我的构造函数

constructor(props) {
   super(props);
   this.state = {
      text: '',
      uid: ''
   }
}

所以我只是发送一个请求，需要在状态中保存响应，但是我收到了一个错误:

TypeError: undefined is not an object (evaluating '_this2.state.text')]

注释的代码行是我尝试修复它的尝试。

更新 1:这是来自 API 的响应

{"data":{"telephone":["Some data"]}}

Answer 1

当组件在渲染函数中挂载时声明该函数

 class Something extends React.Component {
  constructor(props) {
      super(props);
      this.state = {
        text: '',
        uid: ''
      }
  }

   getCode = (text) => {
      fetch('url', {
        method: 'POST',
        headers: {
          Accept: 'application/json',
          'Content-Type': 'application/json'
        },
        body: JSON.stringify({
          "telephone": text, 
          "password": "123123"
        })
      }).then(response => response.json())
      .then(response => {
        console.log(this.state.text)
        console.log(this.state.uid)

        this.setState({uid : response.data.telephone})
        console.log(this.state.uid)
      // this.setState({uid: response["data"]["telephone"]})
      // console.log(this.state.uid); 
      })
  }

  render() {
    return(
      //...you can call it this.getCode(/..../)
    )
  }

}