可能性のある未承諾の拒否（id：0）警告

Question

私のAsyncStorageアイテムが空の場合、次の警告メッセージが表示されます"未処理のプロミス拒否（ID：0）の可能性があります"だから私の約束：拒絶？

マイコード：

componentDidMount() { 
     try { 
      // This warning only appears when 'connections' item is empty 
      AsyncStorage.getItem('connections').then((token) => { 
       token = JSON.parse(token); 

       const getSectionData = (dataBlob, sectionId) => dataBlob[sectionId]; 
       const getRowData = (dataBlob, sectionId, rowId) => dataBlob[`${rowId}`]; 

       const ds = new ListView.DataSource({ 
        rowHasChanged: (r1, r2) => r1 !== r2, 
        sectionHeaderHasChanged: (s1, s2) => s1 !== s2, 
        getSectionData, 
        getRowData, 
       }); 

       const {dataBlob, sectionIds, rowIds} = this.formatData(token); 

       this.setState({ 
        dataSource: ds.cloneWithRowsAndSections(dataBlob, sectionIds, rowIds), 
       }); 
      }); 
     }catch(error) { 
      console.log(error); 
     } 
    } 

あなたが約束を拒否するキャッチする必要

Answer 1

：

componentDidMount() { 
    // This warning only appears when 'connections' item is empty 
    return AsyncStorage.getItem('connections').then((token) => { 
    token = JSON.parse(token); 

    const getSectionData = (dataBlob, sectionId) => dataBlob[sectionId]; 
    const getRowData = (dataBlob, sectionId, rowId) => dataBlob[`${rowId}`]; 

    const ds = new ListView.DataSource({ 
     rowHasChanged: (r1, r2) => r1 !== r2, 
     sectionHeaderHasChanged: (s1, s2) => s1 !== s2, 
     getSectionData, 
     getRowData, 
    }); 

    const { dataBlob, sectionIds, rowIds } = this.formatData(token); 

    this.setState({ 
     dataSource: ds.cloneWithRowsAndSections(dataBlob, sectionIds, rowIds), 
    }); 
    }).catch(error => { 
    console.log(error); 
    }) 
}