React Native 使用回调值重新启动动画

uttx8gqw  于 6个月前  发布在  React
关注(0)|答案(1)|浏览(68)

我有一个循环动画,其中包括几个简单的动画:

Animated.sequence([
        Animated.timing(this.state.animateUp, {toValue: 0, duration: 1500}),
        Animated.timing(this.state.fadeValue, {toValue: 1, duration: 500}),
        Animated.parallel([
          Animated.timing(this.state.opacity, {toValue: 0, duration: 1000}),
          Animated.timing(this.state.frontRotation, { toValue: 1, duration: 300, }),
        ]),

        Animated.timing(this.state.toWhite, {toValue: 1, duration: 1000, delay: 11500}),
      ]);

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我试图阻止他们接触一个功能,停止每个动画一样:

this.state.animateUp.stopAnimation(this.callback)


然后在第二个触摸手势,我想运行相同的动画与回调值。有没有什么办法传递回调值回函数,它是如何实现的?
先谢谢了!
编辑:动画没有开始。

constructor(props) {
    super(props);
    this.state = {
      opacity: new Animated.Value(1),
      animateUp: new Animated.Value(-500),
      animateUpTime: new Animated.Value(1500),
      fadeValue: new Animated.Value(0),
      fadeValueTime: new Animated.Value(500),
      toWhite: new Animated.Value(0),
      toWhiteTime: new Animated.Value(11500),
      measurements: {},
      frontRotation: new Animated.Value(0),
      frontRotationTime: new Animated.Value(300),
      paused: false

    };
  }
  testPause(){
    this.animateUpListener = this.state.animateUp.addListener(({value}) => this.animateUpValue = value)
    this.fadeValueListener = this.state.fadeValue.addListener(({value}) => this.fadeValue = value)
    this.opacityListener = this.state.opacity.addListener(({value}) => this.opacityValue = value)
    this.frontRotationValueListener = this.state.frontRotation.addListener(({value}) => this.frontRotationValue = value)
    this.toWhiteListener = this.state.toWhite.addListener(({value}) => this.toWhiteValue = value)
    if(this.state.paused){
      this.state.animateUpTime = (1-this.animateUpValue)/1500
      this.state.fadeValueTime = (1-this.fadeValue)/500
      this.state.opacityValueTime = (1-this.opacityValue)/1000
      this.state.frontRotationTime = (1-this.frontRotationValue)/300
      this.state.toWhiteTime = (1-this.toWhiteValue)/11500

      this.setState({paused: false})
    } else {
      this.state.animateUp.stopAnimation();
      this.state.fadeValue.stopAnimation();
      this.state.opacity.stopAnimation();
      this.state.frontRotation.stopAnimation();
      this.state.toWhite.stopAnimation();
      this.setState({paused: true})}

}
  render() {
    var spin = this.state.frontRotation.interpolate({
      inputRange: [0, 1],
      outputRange: ['0deg', '90deg']
    })

    return (

    );
  }

   animateFront() {

    return Animated.sequence([
        Animated.timing(this.state.animateUp, {toValue: 0, duration: this.state.animateUpTime}),
        Animated.timing(this.state.fadeValue, {toValue: 1, duration: this.state.fadeValueTime}),
        Animated.parallel([
          Animated.timing(this.state.opacity, {toValue: 0, duration: this.state.opacityValueTime}),
          Animated.timing(this.state.frontRotation, { toValue: 1, duration: this.state.frontRotationTime, }),
        ]),

        Animated.timing(this.state.toWhite, {toValue: 1, duration: this.state.frontRotationTime, delay: 11500}),
      ]).start(() => this.restartAnimation());

   }

componentDidMount(){
  this.animateFront()
}
    restartAnimation(){
        this.animateUpValue = -500; //initialvalue
        this.fadeValue = 0; //initialvalue
        this.opacity = 1;
        this.toWhite = 0;
        this.frontRotation = 0;
        this.video.seek(0);
        this.state.animateUp.setValue(-500); //initialValue
        this.state.fadeValue.setValue(0); //initialValue
        this.state.opacity.setValue(1);
        this.state.toWhite.setValue(0);
        this.state.frontRotation.setValue(0);

    }
}

7eumitmz

7eumitmz1#

您可以通过计算最终值和暂停时的剩余时间来实现暂停和恢复,并使用这些值恢复动画。
首先,将侦听器添加到动画值并保存这些值。

this.animateUpListener = this.state.animateUp.addListener(({value}) => this.animateUpValue = value);
this.fadeValueListener = this.state.fadeValue.addListener(({value}) => this.fadeValue = value);

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类似地,为所有其他动画添加侦听器。之后,序列代码将如下所示。

Animated.sequence([
        Animated.timing(this.state.animateUp, {toValue: 0, duration: 1500}),
        Animated.timing(this.state.fadeValue, {toValue: 1, duration: 500}),
        Animated.parallel([
          Animated.timing(this.state.opacity, {toValue: 0, duration: 1000}),
          Animated.timing(this.state.frontRotation, { toValue: 1, duration: 300, }),
        ]),

        Animated.timing(this.state.toWhite, {toValue: 1, duration: 1000, delay: 11500}),
      ]).start(() => this.restartAnimation());


按下按钮时(第一次交互),在所有动画值上调用stop animation。此时,存储在侦听器中的值将具有动画暂停的值。例如,如果animateUp已经完成并且fade正在运行,则此.fadeValue此时可能具有0.25 etc值。并且此.state.animateUp将已经具有最终值,即0,所以我们重新开始的时候它不会运行

this.state.animateUp.stopAnimation();
this.state.fadeValue.stopAnimation();


现在你需要计算动画的剩余时间。如果从fadeValue 0到1的总时间是1500((1-0)/1500),那么,渐变动画的其余部分的时间可以用相同的方法计算((1-0.25)/1500)。这将是您的简历部分的动画持续时间。公式为((finalValue - currentValue)/totalTime)。每个动画的当前值将是存储在侦听器中的值。
现在,当再次按下按钮时,您将按照上面的描述计算每个动画值的剩余时间,并将使用上面计算的持续时间再次启动动画序列。如果animateUp已完成且fadeValue正在运行,则使用公式的animateUp的持续时间将为0。您将使用更新的持续时间调用动画序列。
序列完成后,可以通过重置所有动画的当前侦听器值来重新启动序列,以便重新计算持续时间,并将所有动画持续时间重置回原始值

restartAnimation() {
  this.animateUpValue = 0; //initialvalue
  this.fadeValue = 0; //initialvalue
  ...

  this.state.animateUp.setValue(0); //initialValue
  this.state.fadeValue.setValue(0); //initialValue
  ...
}


让我知道如果你有任何问题的理解。

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