Question

我正在尝试使用AsyncStorage获取数据。每当我调用我的动作创建者 requestData 并对传递的数据进行控制时，我得到类似下面的内容。我有两个版本的getItem。在这两个版本中我都获得了属性字段的无用值。属性值应该是可读的

{＆＃34; FROM日期＆＃34;：＆＃34; 20160601＆＃34;＆＃34; TODATE＆＃34;：＆＃34; 20160701＆＃34;＆＃34;属性＆＃34 ;：{＆＃34; _40＆＃34;：0，＆＃34; _65＆＃34;：0，＆＃34; _55＆＃34;：空，＆＃34; _72＆＃34;：空}，＆＃ 34; URL＆＃34;：＆＃34; / ABC / ABC / XYZ＆＃34;}

 async getItem(item) {
  let response = await AsyncStorage.getItem(item);
  let responseJson = await JSON.stringify(response);
  return responseJson;
}


async getItem(item) {
  try {
    const value =  AsyncStorage.getItem(item).then((value) => { console.log("inside componentWillMount method call and value is "+value);
    this.setState({'assetIdList': value});
     }).then(res => {
    return res;
  });
    console.log("----------------------------value--------------------------------------"+value);
    return value;
  } catch (error) {
    // Handle errors here
    console.log("error is "+error);
  }
}

componentWillMount() {
    requestData({
      fromDate: '20160601',
      toDate: '20160701',
      assetId: this.getItem(cmn.settings.property),
      url: '/abc/abc/xyz'
    });
  }

Answer 1

您将财产作为承诺，您需要解决它。尝试使用链接。

 assetId: this.getItem(cmn.settings.property).then((res) => res)
          .catch((error) => null);

Answer 2

由于AsyncStorage本质上是异步的，因此您必须等待它返回对象然后调用您的requestData方法;类似于以下内容 -

class MyComponent extends React.Component {
  componentWillMount() {
    this.retrieveFromStorageAndRequestData();  
  }      

  async getItem(item) {
    let response = await AsyncStorage.getItem(item);
    // don't need await here since JSON.stringify is synchronous
    let responseJson = JSON.stringify(response); 
    return responseJson;
  }

  async retrieveFromStorageAndRequestData = () => {
    let assetId = await getItem(cmn.settings.property);  
    requestData({
      fromDate: '20160601',
      toDate: '20160701',
      assetId,
      url: '/abc/abc/xyz'
    }) ;
  }

  // rest of the component

  render() {
    // render logic
  }
}

AsyncStorage.getItem in native native不按预期工作

2 个答案: