以下是使用 ReactNative 代码的片段:
const assetRef = firebase.database().ref...;
const residualRef = firebase.database().ref...;
useEffect(() => {
const assetsHook = assetRef
.on('value', (snapshot) => {
const newOwner = [];
const newAssets = [];
const assets = snapshot.val();
snapshot.forEach((childSnapshot) => {
var childKey = childSnapshot.key;
var childData = childSnapshot.val();
newOwner.push(childKey);
newAssets.push(childData);
});
//console.log(owner.length)
setOwner(newOwner);
setAssets(newAssets);
},
error => {
console.log(error)
}
);
return () => {
assetsHook()
}
}, []);
useEffect(() => {
const residualHook = residualRef
.on('value', (snapshot) => {
const res = [];
snapshot.forEach((childSnapshot) => {
res.push(childSnapshot);
});
//console.log(owner.length)
setResidual(res);
},
error => {
console.log(error)
}
);
return () => {
residualHook()
}
}, []);
有没有办法防止错误信息出现?我已经尝试了所有我认为我从文档中理解的内容。我也尝试过使用一个很长的 useEffect 函数,但它仍然出现错误。