React-Native/Redux错误:请求的值不是对象的键

const initialState = {
  data: [],
  error: null,
};

const reducer = (state = initialState, action) => {
  switch (action.type) {
    case 'FETCH_DATA_SUCCESS':
      return {
        ...state,
        action.payload: action.payload, // 错误的代码
      };
    case 'FETCH_DATA_FAILURE':
      return {
        ...state,
        error: action.payload,
      };
    default:
      return state;
  }
};

const reducer = (state = initialState, action) => {
  switch (action.type) {
    case 'FETCH_DATA_SUCCESS':
      return {
        ...state,
        data: action.payload, // 修正后的代码
      };
    case 'FETCH_DATA_FAILURE':
      return {
        ...state,
        error: action.payload,
      };
    default:
      return state;
  }
};