How to make svg animation with Animated in react-native

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栀梦
栀梦 2021-02-01 09:29

ReactNative:


    
        

        
3条回答
  •  梦如初夏
    2021-02-01 10:07

    Use setNativeProps for Much Better Performance.

    I did some more tinkering and found a more performant method that makes use of addListener and setNativeProps.

    Constructor

    constructor(props) {
      super(props);
    
      this.state = { circleRadius: new Animated.Value(50) };
    
      this.state.circleRadius.addListener( (circleRadius) => {
        this._myCircle.setNativeProps({ r: circleRadius.value.toString() });
      });
    
      setTimeout( () => {
        Animated.spring( this.state.circleRadius, { toValue: 100, friction: 3 } ).start();
      }, 2000)
    }
    

    Render

    render() {
      return(
        
           this._myCircle = ref } cx="250" cy="250" r="50" fill="black" />
        
      )
    }
    

    Result

    And this is what the animation looks like when the 2 second (2000 millisecond) timeout triggers.

    circle animation with setnativeprops

    So, the main thing you needed to change was using setNativeProps instead of using setState in your listener. This makes a native call and bypasses re-calculating the entire component, which in my case was very complex and slow to do.

    Thanks for leading me towards the listener approach!

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