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react-redux connect不会重新渲染组件,但会更新道具

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我有一个关于react-redux的问题,我正在玩一些小的测试代码,以了解它是如何工作的 .

Git repository with problematic code

一切看起来都正确,动作生成器,减速器,调度器,mapStateToProps和连接功能 .

我也会在这里粘贴代码:

没有国家变异 .

但是当子组件Todo(index.jsx)调用从main(有问题的组件)TodoBox(index.jsx)传递给它的函数(onClick事件)时,然后1.调度程序被触发2. reducer被触发并返回具有预期更新的新状态3 .mapStateToProps被触发并返回预期结果

但TodoBox组件不重新渲染从浏览器控制台我可以看到TodoBox的this.props已更新值 .

发生了什么,我无法理解,检查了很多文章和例子,但没有任何匹配 .

谁能发现问题,我需要帮助 .

app.js(反应入口点)

import React from 'react';
import ReactDOM from 'react-dom';
import TodoBox from './views/index.jsx';
import { createStore } from 'redux';
import { Provider } from 'react-redux';
import * as actions from './redux_actions.js';

var data = JSON.parse(document.getElementById('initial-data').getAttribute('data-json'));

const todosReducer = function (state={todos: data}, action) {
  switch(action.type) {
    case actions.UPDATE_TODO:
        let newState = Object.assign({}, state)
        let upd1 = updateRow(newState.todos, 'titel', action.todoUpdate.id, 'checked', action.todoUpdate.checked)
        newState.todos = updateRow(upd1, 'titel', action.todoUpdate.id, 'detail', action.todoUpdate.checked ? 'Done' : 'Sorry not done')
        return newState
      break;
    default:
        return state;
  }
}

function updateRow(tab, where, val, updfield, val2) {
    tab.forEach( (row) => {
        row[where] === val ? row[updfield] = val2 : null
    })
    return tab
}

var Store = createStore(todosReducer)

ReactDOM.render(<Provider store={Store}><TodoBox /></Provider>, document.getElementById("app"));

index.jsx

import React from 'react';
import * as Redux from 'redux';
import { connect } from 'react-redux'
import * as actions from '../redux_actions.js'


class TodoBox extends React.Component {
        render() {
            return (
                <div className="todoBox">
                    <h1>Todos</h1>
                    <TodoList data={this.props.todos} func={this.props.handleChange}/>
                    <TodoForm />
                </div>
            );
        }
    }



class TodoList extends React.Component {
  render() {
     let todo = this.props.data.map( (todos) => { return <Todo titel={todos.titel} func={this.props.func} check={todos.checked} key={todos.titel}>{todos.detail}</Todo> } )
     return (
        <div className="todoList">
            <table style={{border: "2px solid black"}}>
              <tbody>
                 {todo}
              </tbody>
            </table>
        </div>
     );
  }
}


class Todo extends React.Component {
   render() {
    return (
      <tr>
        <td style={style.tableContent}>
           <input id={this.props.titel} type="checkbox" checked={this.props.checked} onChange={this.props.func}/>
        </td>
        <td style={style.tableContent}>{this.props.titel}</td>
        <td style={style.tableContent}>{this.props.children}</td>
      </tr>
    );
   }
}


Todo.propTypes = {
   titel: React.PropTypes.string.isRequired
}


class TodoForm extends React.Component {
  render() {
    return (
        <div className="todoForm">
        I am a TodoForm.
        </div>
     );
  }
}

let style = {
        tableContent: {
            border: "1px solid black"
        }
    };


const mapStateToProps = function (state) {
   return { todos: state.todos }
}

const mapDispatchToProps = function(dispatch) {
  return {
    handleChange: function(event) {
      dispatch(actions.actionUpdateTodo({id: event.target.id, checked: event.target.checked}));
    }
  }
}

export default connect(mapStateToProps, mapDispatchToProps)(TodoBox)

redux_actions.jsx

export const UPDATE_TODO = 'UPDATE_TODO'

export function actionUpdateTodo(todoUpdate) {
  return { type: UPDATE_TODO, todoUpdate: todoUpdate }
}

1 回答

  • 0

    请检查http://redux.js.org/docs/Troubleshooting.html

    看来你正在改变你的商店 . 问题出在你的减速机上 .

    我强烈建议你阅读pure functions .

    const todosReducer = function (state={todos: data}, action) {
      switch(action.type) {
        case actions.UPDATE_TODO:
            let newState = Object.assign({}, state)
            let upd1 = updateRow(newState.todos, 'titel', action.todoUpdate.id, 'checked', action.todoUpdate.checked)
            newState.todos = {...updateRow(upd1, 'titel', action.todoUpdate.id, 'detail', action.todoUpdate.checked ? 'Done' : 'Sorry not done')} //should do the trick. Although I would strongly suggest you to refactor the updateRow function.
            return newState //even so you are returning a newState, the reference value (todos) is not a new instance.
          break;
        default:
            return state;
      }
    }
    
    function updateRow(tab, where, val, updfield, val2) {
        tab.forEach( (row) => {
            row[where] === val ? row[updfield] = val2 : null
        })
        return tab
    }
    

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