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我有一個圖標作爲圖像,我想在狀態屬性更改時更改圖標。下面是相關代碼:正確react-native:當狀態發生變化時,圖像不會重新渲染
<TouchableHighlight underlayColor="rgba(0,0,0,0)" style={styles.playButton} onPress={this._handleStartPress}>
<Image source={(this.state.started) ? require('./Control-pause.png') : require('./Control-play.png')} resizeMode="contain" style={styles.icon}/>
</TouchableHighlight>
狀態變化預期(某些控制檯日誌verifed),但不知何故,圖像不會重新渲染和改變時this.state.started
變化。圖像的路徑也是正確的。
任何想法有什麼問題?
編輯:全成分:
import React, {
AppRegistry,
Component,
StyleSheet,
Text,
TouchableHighlight,
View,
ScrollView,
Vibration,
AlertIOS,
Image
} from 'react-native'
/*import Icon from 'react-native-vector-icons/FontAwesome';*/
const timer = require('react-native-timer');
const Button = require('./components/Button.js');
const PlayIcon = require('./Control-play.png');
const PauseIcon = require('./Control-pause.png');
class Project extends Component {
constructor(props) {
super(props);
this.state = {
timerValue: 25*60,
count: 0,
started: false,
};
this._tick = this._tick.bind(this);
this._runClock = this._runClock.bind(this);
this._stopClock = this._stopClock.bind(this);
this._handlePomodoroPress = this._handlePomodoroPress.bind(this);
this._handlePausePress = this._handlePausePress.bind(this);
this._getMinsSecs = this._getMinsSecs.bind(this);
this._finishedTimer = this._finishedTimer.bind(this);
this._handleStartPress = this._handleStartPress.bind(this);
}
_tick() {
if (this.state.timerValue > 0) {
this.setState({timerValue: this.state.timerValue - 1});
} else {
this._finishedTimer();
}
}
_finishedTimer() {
this.setState({started: false});
timer.clearInterval('timer');
Vibration.vibrate();
AlertIOS.alert("Time's up!");
}
_runClock() {
this.setState({started: true});
console.log("running: ", this.state.started);
timer.setInterval('timer', this._tick, 1000);
}
_stopClock() {
this.setState({started: false});
console.log("running: ", this.state.started);
timer.clearInterval('timer');
}
_getMinsSecs(seconds) {
let mins = Math.floor(seconds/60);
let secs = seconds - mins * 60;
return (mins < 10 ? "0" : "") + mins + ":" + (secs <10 ? "0" : "") + secs;
}
_handleStartPress() {
if (!this.state.started) {
this._runClock();
} else {
this._stopClock();
}
}
_handlePomodoroPress() {
if (!this.state.started) {
this.setState({timerValue: 25*60});
}
}
_handlePausePress() {
if(!this.state.started) {
this.setState({ timerValue: 5*60 });
}
}
render() {
return (
<View style={styles.container}>
<View style={styles.timeWrapper}>
<View style={styles.line}/>
<Text style={styles.time}>{this._getMinsSecs(this.state.timerValue)}</Text>
<View style={styles.line}/>
</View>
<TouchableHighlight underlayColor="rgba(0,0,0,0)" style={styles.playButton} onPress={this._handleStartPress}>
<Image source={(this.state.started) ? require('./Control-pause.png') : require('./Control-play.png')} resizeMode="contain" style={styles.icon}/>
</TouchableHighlight>
<View style={styles.buttonWrapper}>
<Button
value="Pomodoro"
onPress={this._handlePomodoroPress}/>
<Button value="Pause" onPress={this._handlePausePress}/>
</View>
</View>
);
}
}
const styles = StyleSheet.create({
container: {
flex: 1,
justifyContent: "space-around",
alignItems: 'center',
backgroundColor: "#7CCF9E"
},
time: {
fontSize: 74,
color: '#fff',
fontWeight: '200'
},
buttonWrapper: {
justifyContent: 'center',
alignItems: 'center'
},
playButton: {
width: 79,
height: 79,
borderRadius: 100,
borderWidth: 3,
borderColor: '#fff',
alignItems: 'center',
justifyContent: 'center'
},
line: {
marginTop: 10,
height: 3,
width: 200,
backgroundColor: '#fff'
},
timeWrapper: {
alignItems: 'center'
},
icon: {
height: 42,
}
});
AppRegistry.registerComponent('Project',() => Project);
像這樣的作品很容易:
<TouchableHighlight underlayColor="rgba(0,0,0,0)" style={styles.playButton} onPress={this._handleStartPress}>
<Text>{this.state.started ? "started" : "stopped"}</Text>
</TouchableHighlight>
EDIT2:
我發現是什麼原因造成的畫面不重新呈現!!!!
當我在StyleSheet中設置尺寸時,它不會重新渲染......如果它沒有尺寸樣式,那麼一切都很好!
是綁定到'this'的'_handleStartPress'方法嗎? – Cherniv
是的,狀態改變(我可以在改變它後將它打印到控制檯) – rasmus1610
我想我也有這個問題,看着我的代碼,我把渲染的邏輯放在外面,只是用了一個變量。 –