3. React

  • 3.17. React shouldComponentUpdate() method

    The shouldComponentUpdate() format of the method is as follows: shouldComponentUpdate(nextProps, nextState) sho...
    2025-10-25 13:34:29 UTC
  • 3.18. React getSnapshotBeforeUpdate () method

    The render() format of the method is as follows: getSnapshotBeforeUpdate(prevProps, prevState) getSnapshotBefor...
    2025-10-25 13:34:29 UTC
  • 3.19. React componentDidUpdate() method

    The componentDidUpdate() format of the method is as follows: componentDidUpdate(prevProps, prevState, snapshot) ...
    2025-10-25 13:34:30 UTC
  • 3.20. React componentWillUnmount() method

    componentWillUnmount() format of the method is as follows: componentWillUnmount() componentWillUnmount() meth...
    2025-10-25 13:34:30 UTC
  • 3.21. React AJAX

    Data from the React component can be accessed through the componentDidMount method, and when getting data from the serve...
    2025-10-25 13:34:29 UTC
  • 3.22. React forms and events

    In this section we will discuss how to use forms in React. HTML form elements are different from other DOM elements in Rea...
    2025-10-25 13:34:29 UTC
  • 3.23. React Refs

    React supports a very special attribute Ref which you can use to bind to the render() on any component of the output...
    2025-10-25 13:34:30 UTC
《地理信息系统原理、技术与方法》  97

最近几年来,地理信息系统无论是在理论上还是应用上都处在一个飞速发展的阶段。 GIS被应用于多个领域的建模和决策支持,如城市管理、区划、环境整治等等,地理信息成为信息时代重要的组成部分之一; “数字地球”概念的提出,更进一步推动了作为其技术支撑的GIS的发展。 与此同时,一些学者致力于相关的理论研究,如空间感知、空间数据误差、空间关系的形式化等等。 这恰好说明了地理信息系统作为应用技术和学科的两个方面,并且这两个方面构成了相互促进的发展过程。