碰到这个问题根据给的提示大概意思是:setState方法仅适用于一个安装好的或者正在安装的组件,出现这个提示通常意味着你在组件卸载之后调用了这个方法。
代码如下,这是一个倒计时组件:
/** * Created by tujiaw on 2017/2/19. */
import React,{ Component } from 'react';
import {
Text,View,StyleSheet,TouchableHighlight,} from 'react-native';
export default class CountDown extends Component {
constructor(props) {
super(props)
this.state = {
time: this.props.time ? this.props.time : 60,disabled: true
}
this._countdown = this._countdown.bind(this)
this._onPress = this._onPress.bind(this)
}
componentDidMount() {
this._countdown();
}
_onPress(){
if (this.state.disabled) {
//nothing
} else {
this.setState({disabled: true});
this._countdown();
if(this.props.onPress){
this.props.onPress();
}
}
}
_countdown(){
var that = this
var timer = function () {
var time = that.state.time - 1;
that.setState({time: time});
if (time > 0) {
setTimeout(timer,1000)
} else {
that.setState({disabled: false});
that.setState({time: that.props.time ? that.props.time : 60});
}
};
setTimeout(timer,1000)
}
render() {
var style = [styles.text];
var component;
if (this.state.disabled) {
component =
<View style={styles.container}>
<TouchableHighlight>
<Text style={styles.disabledText}>{this.props.text}({this.state.time})</Text>
</TouchableHighlight>
</View>
} else {
component =
<View>
<TouchableHighlight
style={styles.container}
onPress={this._onPress.bind(this)}>
<Text style={styles.enableText}>{this.props.endText || '重新获取'}</Text>
</TouchableHighlight>
</View>
}
return (
component
)
}
}
var styles = StyleSheet.create({
container: {
flexDirection: 'row',width: 100,height: 40,backgroundColor: '#ed7b66',margin: 10,justifyContent: 'center',alignItems: 'center',borderRadius: 4,},disabledText: {
color: '#fff',enableText: {
color: '#fff',}
});
可以看到在 _countdown方法中每秒中调用一次timer方法去递减秒数,当组件unmounted之后这个timer并没有停止,所以出现了上面的问题。
解决办法:
将每次setTimeout返回的ID保存起来,在componentWillUnmount方法中clearTimeout
componentWillUnmount() {
clearTimeout(this.state.timeid)
}
_countdown(){
var that = this
var timer = function () {
var time = that.state.time - 1;
that.setState({time: time});
if (time > 0) {
that.setState({ timeid: setTimeout(timer,1000) })
} else {
that.setState({disabled: false});
that.setState({time: that.props.time ? that.props.time : 60});
}
};
this.setState({ timeid: setTimeout(timer,1000) })
}