3. React

  • 3.1. React tutorial

    React is a JAVASCRIPT library for building user interfaces. React is mainly used to build UI, and many people t...
    2025-10-25 13:34:30 UTC
  • 3.2. React installation

    React can be downloaded and used directly, and many learning examples are provided in the download package. This tutorial ...
    2025-10-25 13:34:29 UTC
  • 3.3. React element rendering

    Elements are the smallest units that make up a React application and are used to describe what is output on the screen. c...
    2025-10-25 13:34:29 UTC
  • 3.4. React JSX

    React use JSX instead of regular JavaScript. JSX is a JavaScript syntax extension that looks a lot like XML. We don’...
    2025-10-25 13:34:30 UTC
  • 3.5. React component

    In this section we will discuss how to use components to make our application easier to manage. Next, let’s package an out...
    2025-10-25 13:34:30 UTC
  • 3.6. React State

    React treats components as a state machine (State Machines). Achieve different states by interacting with the user, and then...
    2025-10-25 13:34:31 UTC
  • 3.7. React Props

    state and props the main difference is that props is immutable, and state it can be changed according to the...
    2025-10-25 13:34:31 UTC
  • 3.8. React event handling

    React element event handling and DOM elements are similar. But there is one grammatical difference: React ev...
    2025-10-25 13:34:30 UTC
  • 3.9. React conditional rendering

    In React can create different components to encapsulate the various behaviors you need. You can then render only some of...
    2025-10-25 13:34:30 UTC
  • 3.10. React list & Keys

    We can use JavaScript’s map() method to create a list. 3.10.1. React instance ¶ Use map() method traverses ...
    2025-10-25 13:34:30 UTC
  • 3.11. React component API

    In this section we will discuss the React component API. We will explain the following seven methods: Set status: setS...
    2025-10-25 13:34:29 UTC
  • 3.12. React component life cycle

    In this section we will discuss the life cycle of React components. The lifecycle of a component can be divided into three...
    2025-10-25 13:34:29 UTC
  • 3.13. React constructor() method

    constructor() : The format of the method is as follows: constructor(props) Before the React component is mounted,...
    2025-10-25 13:34:29 UTC
  • 3.14. React getDerivedStateFromProps () method

    getDerivedStateFromProps() the format of the method is as follows: static getDerivedStateFromProps(props, state) ...
    2025-10-25 13:34:31 UTC
  • 3.15. React render() method

    The render() format of the method is as follows: ReactDOM.render(element, container[, callback]) render() met...
    2025-10-25 13:34:30 UTC
  • 3.16. React componentDidMount() method

    The componentDidMount() format of the method is as follows: componentDidMount() componentDidMount() method is...
    2025-10-25 13:34:29 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。