reactjs:无法映射状态,因为它未定义/错误

我无法描绘我的状态,传给我的孙子 EmailDetails . 我可以控制台将其记录到,直到尝试在 电子邮件详细信息 .

 import React, { Component } from "react";
    import IssueBox from "./issuebox.js";
    import "./App.css";

    class App extends Component {
      constructor(props) {
        super(props);

        this.state = {
          isLoaded: false,
          emails: [],
          counter: 0,
          title: "Test run",
          value: "",
          selectedEmailId: 0,
          currentSection: "inbox"
        };
      }

      componentDidMount() {
        fetch("blah")
          .then(res => res.json())
          .then(result => {
            const emails = result.data;
            console.log("resutl state: ", emails);
            let id = 0;
            for (const email of emails) {
              email.id = id++;
            }
            this.setState({
              isLoaded: true,
              emails: emails
            });
          });
      }

      handleClickReproducibleCounter(e) {
        let count = this.state.increment
          ? this.state.count + 1
          : this.state.count - 1;

        let increment = this.state.increment;

        if (count === 0) {
          increment = true;
        } else if (count >= 2) {
          increment = false;
        }

        this.setState({
          count,
          increment
        });
      }

      render() {
        return (
          <div className="App">
            <div>
              emails={this.state.emails}
              selectedEmailId={this.state.selectedEmailId}
              onEmailSelected={id => {
                this.openEmail(id);
              }}
              handleClickReproducibleCounter={this.handleClickReproducibleCounter}
            </div>
          </div>
        );
      }
    }

//数据如下:

[
  {
    groupID: "65da6a",
    urls: [
      {
        id: 85,
        searchedurl: "https://www.yahoo.com",
        errorurl: "https://www.yahoo.com/error505",
        count: 1,
        reproducible: false,
        reproducible_counter: 0
      },
      {
        id: 84,
        searchedurl: "https://www.gmail.com",
        errorurl: "https://www.gmail.com/error404",
        count: 1,
        reproducible: false,
        reproducible_counter: 0
      }
    ]
  },
  {
    groupID: "d4127e",
    urls: [
      {
        id: 3,
        searchedurl: "agwscc",
        errorurl: "xyqa",
        count: 1,
        reproducible: false,
        reproducible_counter: 0,
        resolved: null
      }
    ]
  }
];

import React, { Component } from "react";
import "./App.css";
import EmailDetails from "./emailDetails";

class IssueBox extends Component {
  constructor(args) {
    super(args);
  }

  render() {

    const currentEmail = this.props.emails.find(
      x => x.id === this.props.selectedEmailId
    );
    console.log("emailDetail view: ", currentEmail); // email obj is present

    return (
      <div className="wrapper">
        <div className="inbox-container">
          <EmailList
            emails={this.props.emails}
            onEmailSelected={this.props.onEmailSelected}
            selectedEmailId={this.props.selectedEmailId}
          />

          <EmailDetails
            email={currentEmail} 
            onReproducibleCounter={this.props.handleClickReproducibleCounter}
            onValidateSumbit={this.props.handleClickValidateSumbission}
            handleTextInputChange={this.props.handleTextInputChange}
          />
        </div>
      </div>
    );
  }
}

export default IssueBox;

//电子邮件详细信息

import React, { Component } from "react";
import "./App.css";

class EmailDetails extends Component {
  constructor(args) {
    super(args);

    this.state = {
      counter: "",
      email: []
    };
  }

  componentDidUpdate(prevProps) {
    if (this.props.email !== prevProps.email) {
      this.setState({ email: this.props.email });
    }
  }

  render() {
    const currentEmail = this.state.email;
    console.log(currentEmail, this.state.email.urls); // able to console obj
    const test = this.state.email.urls.map(obj => {
      //error occurs here
      console.log(obj);
    });
    return (
      <div className="email-content">
        <div className="email-content__header">
          <h3 className="email-content__subject">Issue</h3>
          <div className="email-content__from">Group:</div>
        </div>
        <div className="email-content__message">
          <table role="table">
            <thead role="rowgroup">
              <tr role="row">
                <th role="columnheader">Searched URL</th>
                <th role="columnheader">Error URL</th>
                <th role="columnheader">NR</th>
                <th role="columnheader">Task</th>
              </tr>
            </thead>
            <tbody role="rowgroup" className="group-row" />
          </table>
        </div>

      </div>
    );
  }
}

export default EmailDetails;

以此为出发点: codepen