使数组在选定的值选择器中作出反应

Question

在选择本机时，我想如何在本机选择器中创建数组，如果选择了值，我想这样做

state = { selected: null, arr: [] }
<Picker
      selectedValue={selected}
      style={{ height: 20, width: 110 }}
      onValueChange={(itemValue, itemIndex) => {
        this.setState({ selected: itemValue })
        this.state.arr.push(selected)
      }}
    >
      {dummy.map((val, idx) => (
        <Picker.Item label={val.attendance} value={val.id} key={idx} />
      ))}
    </Picker>

如果我选择value = ['present'，'present'，'sick'，离开']

Answer 1

尝试一下

<Picker
  selectedValue={selected}
  style={{ height: 20, width: 110 }}
  onValueChange={(itemValue, itemIndex) => {
    this.setState({
      selected: itemValue,
      arr: [...this.state.arr].push(selected)
    })
  }}
>