13.监听器this.html 1.4 KB

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  1. <!DOCTYPE html>
  2. <html lang="en">
  3. <head>
  4. <meta charset="UTF-8">
  5. <meta name="viewport" content="width=device-width, initial-scale=1.0">
  6. <title>Document</title>
  7. <script src="./babel.min.js"></script>
  8. <script src="./react.development.js"></script>
  9. <script src="./react-dom.development.js"></script>
  10. </head>
  11. <body>
  12. <div id="root"></div>
  13. <script type="text/babel">
  14. const root = ReactDOM.createRoot(document.getElementById("root"));
  15. class App extends React.Component {
  16. constructor(props) {
  17. super(props);
  18. this.state = {
  19. }
  20. // this.handleClick = this.handleClick.bind(this);
  21. }
  22. handleClick() {
  23. console.log(this)
  24. }
  25. render() {
  26. return (
  27. <div>
  28. <button onClick={this.handleClick.bind(this)}>点击</button>
  29. <button onClick={()=>{
  30. console.log(this)
  31. }}>点击2</button>
  32. </div>
  33. )
  34. }
  35. }
  36. root.render(<App/>);
  37. console.log(this,'121')
  38. let obj = {
  39. aa:12,
  40. a() {
  41. console.log(this);
  42. }
  43. }
  44. obj.a()
  45. var b = obj.a;
  46. b();
  47. b.call(window)
  48. </script>
  49. </body>
  50. </html>