標籤:element name ges lag 文字 char div script ima
就是男默女淚的立flag!
1 <!DOCTYPE html> 2 <html lang="en"> 3 <head> 4 <meta charset="UTF-8"> 5 <title>Title</title> 6 <style> 7 .video-box{ 8 width: 1000px; 9 height: 500px;10 background-color: skyblue;11 margin: 50px auto;12 }13 body.night{14 background-color: #333;15 color: #fff ;16 }17 body.night button{18 background-color: #ccc;19 color:#fff;20 }21 22 </style>23 <script>24 window.onload = function () {25 var btn = document.getElementsByTagName(‘button‘);26 var flag = false;27 btn[0].onclick = function () {28 if(!flag) {29 document.body.className = "night";30 btn[0].innerHTML = "開燈";31 }else {32 document.body.className = "";33 btn[0].innerHTML = "關燈";34 }35 flag = !flag;36 }37 38 // var flag = true;39 // btn[0].onclick = function () {40 // flag = !flag;41 // if(!flag) {42 // document.body.className = "night";43 // btn[0].innerHTML = "開燈";44 // }else {45 // document.body.className = "";46 // btn[0].innerHTML = "關燈";47 // }48 //49 // }50 }51 </script>52 </head>53 <body>54 <button>關燈</button>55 <h2>頁面的文字</h2>56 <div class="video-box"></div>57 </body>58 </html>
JavaScript--開關思想