fengchuanyu hai 6 días
pai
achega
52ab8a8120
Modificáronse 1 ficheiros con 42 adicións e 0 borrados
  1. 42 0
      4_BOM&DOM/练习1_倒计时.html

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4_BOM&DOM/练习1_倒计时.html

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+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Document</title>
+    <style>
+        .box{
+            width: 300px;
+            height: 300px;
+            background-color: #999;;
+            position: fixed;
+            top: 50%;
+            left: 50%;
+            margin-top: -150px;
+            margin-left: -150px;
+            color: #fff;
+            font-weight: bold;
+            font-size: 50px;
+            text-align: center;
+            line-height: 300px;
+        }
+    </style>
+</head>
+<body>
+    <div class="box">
+        <span class="num">10</span>
+    </div>
+    <script>
+        var i = 10;
+        var oNum = document.getElementsByClassName("num")[0];
+        var timer = setInterval(function(){
+            i--;
+            console.log(i);
+            oNum.innerText = i;
+            if(i==0){
+                clearInterval(timer);
+            }
+        },1000)
+    </script>
+</body>
+</html>