Redux状态/子组件渲染触发器在反应吗？

Question

I have a react component called contacts and subcomponents called 'comments' and 'card'. All three are connected to the contactReducer

If I wrote a reducer for contacts as follows:

const reducer = ( state = null, action = null ) => {
    switch (action.type) {
        case GET_CONTACT:
            return [
                ...state, 
                contact: action.payload
            ]
        case GET_CARD:
            return [
                ...state, 
                card: action.payload
            ]
        case GET_COMMENTS:
            return [
                ...state, 
                comments: [...action.payload]
            ]
        default:
            return state;
    }
}
export default reducer;

1.a) Does the parent component render each time the subcomponent receives updated props because they are all connected to the contactReducer ?

1.b) If I'm going about this the wrong way how would you recommend it be handled?

2) after each action has update the contactReducer once do I end up with the following object or am I way off?

contactsReducer = {
    contact : {someData},
    card    : {someData},
    comments: [someData, someData, ...]
}

Answer 1

Any object that receives a new object as a prop or if their state changes will re-render in accordance with react's diffing algorithm. That is assuming you don't overwrite the componentShouldUpdate method.

1a - the parent will receive the new state from the reducer and re-render anything that should change.

1b / 2 - In your current implementation, you will have a single array with a mix of objects with keys varying from contact, card, and comments . You should look into redux's functionality combineReducers and create a reducer for each of those keys. I would strongly recommend you watch a video series on Redux to see the design patterns, it will go a long way - video