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"Possible Unhandled Promise Rejection(id:0)"したがって、私の質問は次のとおりです。PromiseRejectionを処理するにはどうすればよいですか?
私のコード:
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[`${rowId}`];
const ds = new ListView.DataSource({
rowHasChanged: (r1, r2) => r1 !== r2,
sectionHeaderHasChanged: (s1, s2) => s1 !== s2,
getSectionData,
getRowData,
});
const {dataBlob, sectionIds, rowIds} = this.formatData(token);
this.setState({
dataSource: ds.cloneWithRowsAndSections(dataBlob, sectionIds, rowIds),
});
});
}catch(error) {
console.log(error);
}
}
あなたは約束の拒絶を捕まえる必要があります:
componentDidMount() {
// This warning only appears when 'connections' item is empty
return AsyncStorage.getItem('connections').then((token) => {
token = JSON.parse(token);
const getSectionData = (dataBlob, sectionId) => dataBlob[sectionId];
const getRowData = (dataBlob, sectionId, rowId) => dataBlob[`${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);
})
}