React useReducer和useState

Question

我开始在一个新项目中实现还原器模式，我想知道useReducer钩子是否与async immutability与useState钩子有相同的问题。

我的意思是：

const [state, setState] = useState('');

const handleChange = e => {

 setState(e.target.value);

 // It doesn't give the current value, it gives the previous one, which is ''
 console.log(state);

 // So i need to set the current value in a variable to avoid the async immutability
 const currentValue = e.target.value;

 console.log(currentValue);

 e.stopPropagation();
}

<input type='text' value={state} onChange={handleChange}>PRESS</button>

对于change钩子，我需要做同样的事情：在 variable中设置当前的？

Answer 1

问题求解

为了避免useReducer挂钩不可变，我们需要在variable中设置current value。然后访问那个变量。

const initialState = {
 value: ''
};

const [state, dispatch] = useReducer(SomeReducerFunction, initialState);

const handleChange = e => {

 dispatch({type: SOME_ACTION_TYPE, payload: e.target.value });

 const currentValue = e.target.value;

 console.log(currentValue);

 e.stopPropagation();
}

<input type='text' value={state} onChange={handleChange}>PRESS</button>