在官方的react-native文档中有一个关于Animated.event方法的部分。例如，他们使用以下代码:

onScroll={Animated.event( 
   // scrollX = e.nativeEvent.contentOffset.x 
   [{ nativeEvent: { 
        contentOffset: { 
          x: scrollX 
        } 
      } 
    }] 
 )} 

我想将正确的值映射到 Animated.event 方法，并且我还想将 onScroll 回调参数映射到我自己的回调。基本上我想做这样的事情:

onScroll={(event) => { 
  myOwnCallback(event.nativeEvent.contentOffset.x) 
  Animated.event( 
    // scrollX = e.nativeEvent.contentOffset.x 
    [{nativeEvent: { 
        contentOffset: { 
          x: scrollX 
        } 
      } 
    }] 
  ) 
}} 

您能解释一下如何做到这一点吗？

请您参考如下方法:

当你查看源代码时:

/** 
   * Takes an array of mappings and extracts values from each arg accordingly, 
   * then calls `setValue` on the mapped outputs.  e.g. 
   * 
   *```javascript 
   *  onScroll={Animated.event( 
   *    [{nativeEvent: {contentOffset: {x: this._scrollX}}}] 
   *    {listener},          // Optional async listener 
   *  ) 
   *  ... 
   *  onPanResponderMove: Animated.event([ 
   *    null,                // raw event arg ignored 
   *    {dx: this._panX},    // gestureState arg 
   *  ]), 
   *``` 
   * 
   * Config is an object that may have the following options: 
   * 
   *   - `listener`: Optional async listener. 
   *   - `useNativeDriver`: Uses the native driver when true. Default false. 
   */ 
  event, 

这就是我让它工作的方式:

onScroll={Animated.event( 
            [{ nativeEvent: { contentOffset: { y: this.state.scrollY } } }], 
  { 
    useNativeDriver: true, 
    listener: event => { 
      const offsetY = event.nativeEvent.contentOffset.y 
      // do something special 
    }, 
  }, 
)}