psq*_*zle 3 javascript reactjs react-hooks use-state
在尝试将两个数组添加到一起时,我遇到了一些奇怪的行为。每个数组块的长度为 50 个项目。我的清单永远不会超过 50。
我已经尝试过使用扩展运算符和 concat 方法,使用和不使用包装函数。没有任何效果
setWordList(wordList => wordList.concat(msg))
setWordList(wordList => [...wordList, msg])
setWordList([...wordList, msg])
setWordList(wordList.concat(msg))
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const [wordList, setWordList] = useState([])
const [isSearching, setIsSearching] = useState(true)
const loadMoreList = (data) => {
console.log(data)
setIsSearching(true)
let already = []
for(let i = 0; i < wordList.length; i++){
already.push({_id: wordList[i]._id})
}
console.log(already)
socket.current.emit('get word list more', {filter: data.filter, already: already});
}
socket.current.on('word list in', (msg) => {
setWordList(wordList => [...wordList, msg])
console.log(msg)
setIsSearching(false)
});
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示例数据(数组长度 = 50)
[{
definition: "1. aufhören zu leben, sein Leben beschließen?Beispiele?“jung sterben”?Wendungen, Redensarten, Sprichwörter?“zum Sterben langweilig, müde, einsam o. Ä...."
id: "dfe03030-0c50-11ea-afa4-098be982e090"
leitner_no: 2
priority: true
priority_time: 1587986213134
reviews: 1
source: "manual"
source_details: "none"
time_stamp: 1583402873665
word: "sterben | starb, gestorben |"
_id: "fb99b7c3-34a4-4e63-a98e-41efbbcfe5fc"}]
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当前列表和传入数据永远不会连接,新数据似乎已经替换了列表中的数据。Console.log
的wordList
内部socket('word list in')
回报率,无论是否有来自先前输入的渲染数据空列表。不知何故,状态似乎没有持续存在。任何帮助将不胜感激。
两个数组都需要展开,如下所示:
setWordList(wordList => [...wordList, ...msg])
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