如何在函数之间传递变量？答案

【问题标题】：how do I pass variables between functions?如何在函数之间传递变量？
【发布时间】：2020-11-12 10:46:34
【问题描述】：

朋友们，下午好。我有两个问题。

如何将 Fulloffset 传递给 scrollToRef 函数？
如何在对象中声明道具，以便它们在所有函数中都可用？我试图避免在每个函数中声明类似“const { arrayOfHeight } = this.props”的内容

export function withScrollToFirstError(Component: t.form.Component): React.ComponentType {
  class ScrollToFirstErrorHOC extends PureComponent<OuterProps & PropsFromState, ComponentState> {
    constructor(props: OuterProps & PropsFromState) {
      super(props);
      this.state = {
        height: 0,
        offset: 0,
      };
    }

    componentDidUpdate() {
      this.existError();
    }

    existError = () => {
      const { currentFieldId, firstFieldId, arrayOfHeight, fieldOffset, fieldErrors } = this.props;
      this.calculateCoordinate();
    };

    calculateCoordinate = () => {
        const fullOffset = offset + fieldOffset[0];
      this.scrollToRef();
    };

    scrollToRef = () => {
      if (this.props.reference) {
        this.props.reference.current.scrollTo({
          x: 0,
          y: 0,
          animated: true,
        });
      }
    };

【问题讨论】：

标签： javascript function react-native scope

【解决方案1】：

将 Fulloffset 传递给 scrollToRef

calculateCoordinate = () => {
      const fullOffset = offset + fieldOffset[0];
      this.scrollToRef(fullOffset); // like this
    };

scrollToRef = (fullOffset) => {
      if (this.props.reference) {
        this.props.reference.current.scrollTo({
          x: 0,
          y: 0,
          animated: true,
        });
      }
    };

全局声明 props

export function withScrollToFirstError(Component: t.form.Component): React.ComponentType {
  class ScrollToFirstErrorHOC extends PureComponent<OuterProps & PropsFromState, ComponentState> {
    constructor(props: OuterProps & PropsFromState) {
      super(props);
      this.state = {
        height: 0,
        offset: 0,
      };
     // initialize here
     this.arrayOfHeight = props.arrayOfHeight;
    }

    componentDidUpdate() {
      this.existError();
    }

    existError = () => {
      // use here like 
      this.arrayOfHeight;
    };
}

【讨论】：