Question

我如何在新的reducer中创建数组？

使用旧的语法ID可以做到这一点：

    const initialState: Comment = {
      fullName: null,
      comment: null
    };

    export function commentReducer(state: Comment[] = [], action: CommentAction.Action) {
      switch (action.type) {
        case CommentAction.ADD_COMMENT:
          return [...state, action.payload];
        case CommentAction.REMOVE_COMMENT:
          state.splice(action.payload, 1);
          return state;
          default:
            return state;
      }

    }

现在在新的reducer中，我这样做但不是数组

    export const initialState: Comment = {
      fullName: null,
      comment: 'null'
    };

    const commentReducer = createReducer(
      initialState,
      on(CommentAction.addcomment, (state, { fullName, comment }) => ({ fullName, comment }))
    );


    export function reducer(state: Comment | undefined, action: Action) {
      return commentReducer(state, action);
    }

我尝试调度，但没有将其添加到数组中，只是替换了它。我做错了什么？

Answer 1

首先：您的initialState应该是一个数组，其次：仅返回一个数组

export const initialStat: Comment[] = [];

const commentReducer = createReducer(
      initialState,
      on(CommentAction.addcomment, (state, { fullName, comment }) => [...state, { fullName, comment }])
    );

  export function reducer(state: Comment[], action: Action) {
      return commentReducer(state, action);
    }

我还在需要的地方将注释类型更改为Comment []

NgRx Reducer-使用新语法使其成为数组

1 个答案: