改了樣式如何再恢復樣式呢?
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>className屬性</title>
<style>
? ? body{ font-size:16px;}
? ? .one{
border:1px solid #eee;
width:230px;
height:50px;
background:#ccc;
color:red;
? ? }
.two{
border:1px solid #ccc;
width:230px;
height:50px;
background:#9CF;
color:blue;
}
</style>
</head>
<body>
? ? <p id="p1" > JavaScript使網頁顯示動態效果并實現與用戶交互功能。</p>
? ? <input type="button" value="添加樣式" onclick="add()"/>
? ? <input type="button" value="恢復樣式" onclick="back1()">
<p id="p2" class="one">JavaScript使網頁顯示動態效果并實現與用戶交互功能。</p>
? ? <input type="button" value="更改外觀" onclick="modify()"/>
? ? <input type="button" value="恢復樣式" onclick="back2()">
<script type="text/javascript">
? ?function add(){
? ? ? var p1 = document.getElementById("p1");
? ? ? p1.className="one";
? ?}
? ?function modify(){
? ? ? var p2 = document.getElementById("p2");
? ? ? p2.className="two";
? ?}
? ?function back1(){
? ? ? var p2 = document.getElementById("p3");
? ? ? p3.className="two";
? ?}
? ?function back2(){
? ? ? var p4 = document.getElementById("p2")
? ? ? p4.className="one";
? ?}
</script>
</body>
</html>
2019-11-29
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>className屬性</title>
<style>
??? body{ font-size:16px;}
??? .one{
?? ??? ?border:1px solid #eee;
?? ??? ?width:230px;
?? ??? ?height:50px;
?? ??? ?background:#ccc;
?? ??? ?color:red;
??? }
?? ?.two{
?? ??? ?border:1px solid #ccc;
?? ??? ?width:230px;
?? ??? ?height:50px;
?? ??? ?background:#9CF;
?? ??? ?color:blue;
?? ?}
?? ?</style>
</head>
<body>
??? <p id="p1" > JavaScript使網頁顯示動態效果并實現與用戶交互功能。</p>
??? <input type="button" value="添加樣式" onclick="add()" id="p3"/>
?? ?<p id="p2" class="one">JavaScript使網頁顯示動態效果并實現與用戶交互功能。</p>
??? <input type="button" value="更改外觀" onclick="modify()"/>
?? ?<script type="text/javascript">
?? ??? function add(){
?? ?????? var p1 = document.getElementById("p1");
?? ?????? var p3= document.getElementById("p3")
?? ?????? if(p1.className=="")
?? ?????? {p1.className="one";p3.value="恢復"}
?? ?????? else {p1.className="";p3.value="添加元素"}
?? ??? }
?? ??? function modify(){
?? ?????? var p2 = document.getElementById("p2");
?? ?????? p2.className="two"
?? ??? }
?? ?</script>
</body>
</html>
可以參考下
2019-10-23
加個按鈕，object.className="none";