英文:
Restart React Native Animation When Component's Props Change
问题
我有一个React Native组件,用于渲染通知文本。我希望文本在稍后淡入和淡出。当设置新的通知文本时,我希望重新启动相同的动画。
我有以下代码:
export default function Notification({ notification }) {
if (!notification) {
return null;
}
const [fadeAnimation] = useState(new Animated.Value(0));
useEffect(() => {
Animated.sequence([
Animated.timing(fadeAnimation, {
toValue: 1,
duration: 500,
useNativeDriver: true,
}),
Animated.delay(3000),
Animated.timing(fadeAnimation, {
toValue: 0,
duration: 500,
useNativeDriver: true,
})]).start()
}, []);
return (
<Animated.View style={{ opacity: fadeAnimation, }}>
<View style={styles.notificaton}>
<Text style={styles.text}>{notification}</Text>
</View>
</Animated.View>
)
}
我了解到我应该能够使用 setValue(0)
来重置动画,然而,我不知道在哪里和何时调用它。
英文:
I have a React Native component rendering a notification text. I want the text to fade in and fade out after a small delay. When a new notification text is set, I want to restart the same animation.
I have the following code:
export default function Notification({ notification }) {
if (!notification) {
return null;
}
const [fadeAnimation] = useState(new Animated.Value(0));
useEffect(() => {
Animated.sequence([
Animated.timing(fadeAnimation, {
toValue: 1,
duration: 500,
useNativeDriver: true,
}),
Animated.delay(3000),
Animated.timing(fadeAnimation, {
toValue: 0,
duration: 500,
useNativeDriver: true,
})]).start()
}, []);
return (
<Animated.View style={{ opacity: fadeAnimation, }}>
<View style={styles.notificaton}>
<Text style={styles.text}>{notification}</Text>
</View>
</Animated.View >
)
}
I read that I should be able to reset the animation with setValue(0)
again, however I do not know where and when to call it.
答案1
得分: 1
work for me
import React, { Component } from 'react';
import { Animated, View } from 'react-native';
class Testing extends Component {
constructor(props) {
super(props);
this.animatedValue = new Animated.Value(0);
}
componentDidUpdate(prevProps) {
if (prevProps.myProp !== this.props.myProp) {
this.startAnimation();
}
}
startAnimation() {
this.animatedValue.setValue(0);
Animated.timing(this.animatedValue, {
toValue: 1,
duration: 1000,
useNativeDriver: true,
}).start();
}
render() {
const { myProp } = this.props;
const opacity = this.animatedValue.interpolate({
inputRange: [0, 1],
outputRange: [0, 1],
});
return (
<View>
<Animated.Text style={{ opacity }}>
My prop val : {myProp}
</Animated.Text>
</View>
);
}
}
export default Testing;
英文:
work for me
import React, { Component } from 'react';
import { Animated, View } from 'react-native';
class Testing extends Component {
constructor(props) {
super(props);
this.animatedValue = new Animated.Value(0);
}
componentDidUpdate(prevProps) {
if (prevProps.myProp !== this.props.myProp) {
this.startAnimation();
}
}
startAnimation() {
this.animatedValue.setValue(0);
Animated.timing(this.animatedValue, {
toValue: 1,
duration: 1000,
useNativeDriver: true,
}).start();
}
render() {
const { myProp } = this.props;
const opacity = this.animatedValue.interpolate({
inputRange: [0, 1],
outputRange: [0, 1],
});
return (
<View>
<Animated.Text style={{ opacity }}>
My prop val : {myProp}
</Animated.Text>
</View>
);
}
}
export default Testing;
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