getDerivedStateFromProps nextProps具有旧值

Question

这很难解释，但是我有一个父组件Profile，其中有许多Profile-info子级。子级具有输入，提交后调用子级Profile中的方法以更新Profle状态的值。 “用户”状态对象是在Axios调用的响应中更新的，但是当触发getDerivedStateFromProps时，nextProps具有旧的用户对象。当在完成用户查找时加载应用程序，然后从应用程序更新道具时，getDerivedStateFromProps可以正常工作，然后在Profile中填充该道具。我不太确定为什么要在这里调用它，因为Profile中不应该有任何甚至在变化的道具？有帮助吗？

static getDerivedStateFromProps(nextProps, prevState) {
    if (nextProps.user !== prevState.user) {
      return {
        user: nextProps.user
      };
    } else {
      return null;
    }
  }

  updateUser(field) {
    const personalInfo = {};
    const corporateInfo = {};

    const merged = { ...this.state.user, ...field };

    const headers = { headers: { Authorization: "Bearer " + getToken() } };
    Axios.put(
      getServerUrl() + "api/Employees/" + this.state.user.employeeId,
      merged,
      headers
    )

      .then(response => {
        console.log(response);
        if (response.status === 200 || response.status === 204) {
          Object.keys(this.state.personalInfo).map(
            k => (personalInfo[k] = merged[k])
          );
          Object.keys(this.state.corporateInfo).map(
            k => (corporateInfo[k] = merged[k])
          );

          //this.props.user = merged;
          this.setState({
            personalInfo: personalInfo,
            corporateInfo: corporateInfo,
            isLoading: false,
            successMessage: "Successfully updated employee",
            user: merged
          });
        } else {
          this.setState({
            validationError: response.data.message
              ? response.data.message
              : "Error editing account",
            isLoading: false
          });
        }
      })
      .catch(error => {
        this.setState({
          validationError: "Error editing account",
          isLoading: false
        });
      });

    console.log("Update user setState", this.state);
  }