Question

TypeError从JoinNavigator启动。

export class JoinNavigator extends React.Component {

  render() {
    return (
      <JoinStackNavigator
        onNavigationStateChange={(prevState, currentState) => {
          this._getCurrentRouteName(currentState)
        }}
      />
    );
  }

  _getCurrentRouteName(navState) {
    if (navState.hasOwnProperty('index')) {
      this._getCurrentRouteName(navState.routes[navState.index])
    } else {
      console.log("Current Route Name:", navState.routeName);
      let regExp = /^AskStep/;
      if(navState.routeName.match(regExp)){
        this.props._changeVisibleStatusBar(); //It's located at this.
      }
    }
  }

}
const mapStateToProps = ({app}) => {
  return app;
};

const mapDispatchToProps = dispatch => {
  return {
    _changeVisibleStatusBar: () => {
      dispatch(changeVisibleStatusBar(false))
    }
  };
};

export default connect(mapStateToProps, mapDispatchToProps)(JoinNavigator);

动作。当我在JoinNavigator上调用该动作时，它可以正常工作。没问题。

import {
  APP_STATUS_BAR
} from './types'

export const changeVisibleStatusBar = (val) => {
  return {
    type: APP_STATUS_BAR,
    payload: {hiddenStatusBar: val}
  }
};

减速器。你可以看到＆＃34; console.log＆＃34;。它的作品。所有数据参数都在React Native Debugger上很好地显示。

import {
  APP_STATUS_BAR
} from '../actions/types';

const INITIAL_STATE = {
  hiddenStatusBar: false,
  isFetching: false,
  error: false
};

export default (state = INITIAL_STATE, action) => {
  switch (action.type) {
    case APP_STATUS_BAR:
      console.log(action); //It's works well.
      return {
        ...state,
        ...action.payload
      };

    default:
      return state;
  }
};

显然， - 从JoinNavigator调用Action。 - 它被派遣并通过Action to Reducer传递。（我看到了console.log）

所以...为什么是TypeError？

TypeError：TypeError：无法读取属性＆＃39; type＆＃39;未定义的

This error is located at:
    in NavigationContainer (at JoinNavigator.js:60)
    in JoinNavigator (created by Connect(JoinNavigator))
    in Connect(JoinNavigator) (at SceneView.js:17)
    in SceneView (at CardStack.js:385)
    in RCTView (at View.js:71)
.....

需要帮助。

谢谢。

Answer 1

尝试在chrome或Firefox中安装redux dev工具，以检查触发的操作。一些未定义的动作正在调度，但很难知道从哪里开始

为什么React-Native中有TypeError？

1 个答案: