试图获取超出范围索引NaN的帧(实时数据库) [英] Tried to get frame for out of range index NaN (realtime database)

问题描述

我正在尝试从Firebase数据库呈现一些行，但出现此错误:

I'm trying to render some rows from firebase database, I'm getting this error:

TaskQueue:任务出错:永久违反:试图获取框架 超出范围指数NaN

TaskQueue: Error with task : Invariant Violation: Tried to get frame for out of range index NaN

  const { currentUser } = firebase.auth();
    var userfavorites = firebase.database().ref(`/users/${currentUser.uid}/favorites/`);
    userfavorites.once('value').then(snapshot => {
      this.setState({ userfav: snapshot.val() })
    })

...

  <FlatList
    data={this.state.userfav}
    renderItem={({ item }) => (
      <Text>{item.favdata}</Text>
    )}
  />

推荐答案

我遇到了此错误，我有一个PHP后端，试图将json_encoded数据放入FlatList.

I came across this error, I had a PHP back-end and trying to get json_encoded data into a FlatList.

问题::REST端点正在返回一个对象，例如

Problem: The REST endpoint was returning an object eg

{"Total_Excavator":2,"Active_Excavator":2,"Total_load":6804}

解决方案:修复了它返回数组的问题，例如

Solution: Fixed it to return an array rather eg

[{"Total_Excavator":2,"Active_Excavator":2,"Total_load":6804}]

记下方括号. 我用$data[] = json_encode($excavatorArray)代替 $data = json_encode($excavatorArray) .希望有一天能对某人有所帮助

Take note of the Square Brackets. I used $data[] = json_encode($excavatorArray) instead of $data = json_encode($excavatorArray) . Hope it helps someone one day

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