dva.js的dispatch的回调

在dva@2中实现回调可以将回调函数作为参数dispatch：

    dispatch({
       type: 'model/fetch',
       payload: {
          resolve,
          id: userId,
       },
       callback: res => {
          console.log(res);
       }
    })

然后在model的effects中这样写:

    *fetch({ payload, callback }, {call}) {
      const response = yield call(services.fetch, payload);
      if (response.code === 0) {
        yield put({
          type: 'reload',
          payload: response,
        });
      if (callback) callback(response);
    }