看了许多资料对Redux还是不是很理解
1.对于全局的State,也就是Store所管理的,初始是在哪里生成的? 之后又是怎么添加进去的?添加之后是不是都在同一个{}中得保证所有属性不重名
2.在Redux模式下,是不是每一个组件(需要state的组件)需要用connect( mapStateToProps ,mapDispatchToProps )(Component);
进行绑定?
3.一个Action是不是所有Reducer都会收到?
然后就是自己在懵逼状态下写的一点代码跑不起来 也没有错误提示:
import React from "react";
import ReactDOM from "react-dom";
import {createStore,bindActionCreators,combineReducers} from "redux";
import {Provider,connect} from "react-redux";
class Counter extends React.Component {
render() {
let { value1, onIncreaseClick, onDecreaseClick, value2, onDoubleClick, onResetClick } = this.props;
return (
<div>
<div>
<p>{value1}</p>
<button onClick={onIncreaseClick}>Increase</button>
<button onClick={onDecreaseClick}>Decrease</button>
</div>
<div>
<p>{value2}</p>
<button onClick={onDoubleClick}>Double</button>
<button onClick={onResetClick}>Reset</button>
</div>
</div>
)
}
}
function mapStateToProps(state) {
return { //obj
value1:state.count,
value2:state.count
}
}
function mapDispatchToProps(dispatch) {
return { //obj
onIncreaseClick(){
dispatch({type:"increase"});
},
onDecreaseClick(){
dispatch({type:"decrease"});
},
onDoubleClick(){
dispatch({type:"double"});
},
onResetClick(){
dispatch({type:"reset"});
}
}
}
function counter1(state = { count: 0 }, action) {
let count = state.count;
switch (action.type) {
case 'increase':
return { count: count + 1 };
case 'decrease':
return { count: count-1 };
default:
return state;
}
}
function counter2(state = { count: 0 }, action) {
let count = state.count;
switch (action.type) {
case 'double':
return { count: count*2 };
case 'reset':
return { count: 0 };
default:
return state;
}
}
let rootReducer = combineReducers({
counter1,
counter2
});
let store = createStore(rootReducer);
let CounterCompo = connect(
mapStateToProps,
mapDispatchToProps
)(Counter);
ReactDOM.render(<Provider store={store}>
<CounterCompo/>
</Provider>,document.getElementById('container'));
找到问题了。。。。combineReducers的坑 用了之后State被划分到各自的Reducer去了