反应原生:<Picker>更改 <Picker.Item> 时丢失 selectedValue标签 [英] react-native: <Picker> loses selectedValue when changing the <Picker.Item> label

问题描述

我想更改我的的的标签，例如当语言改变时，由另一个按钮触发(react-redux).

key 和 value 应该保持不变，只是 label 发生了变化.

key and value should stay the same, just the label changes.

不幸的是，结果是重新渲染(?)并且 selectedValue 更改为第一个 s(不是默认值！).

Unfortunately the result is a re-rendering(?) and the selectedValue changes to the first <Picker.Item>s (not to the default!).

<Picker 
    selectedValue={this.props.myValue}
    onValueChange={(newValue) => this.props.setMyValue(newValue);}}>

    {this.props.myOptions.map((s, i) => {
        let l = modify(s);
        return <Picker.Item key={i} value={s} label={l}/>      
    })}
</Picker>

只要 label 发生变化，问题就会发生，例如通过在每次更改时添加当前日期:

The problem occurs as soon as the label changes, e.g. by adding the current date on every change:

export default function modify(string) {
    // return string; // works
    return string + '_i_change_' + new Date(); // doesn't work
}

我感谢每一个建议.提前致谢！

I appreciate every advice. Thanks in advance!

推荐答案

遇到了同样的问题.您可能需要将 selectedValue 设为字符串.例如:

ran into same issue. You may need to make the selectedValue a string. eg:

selectedValue={this.props.myValue.toString()}

这篇关于反应原生:<Picker>更改 <Picker.Item> 时丢失 selectedValue标签的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！