我试图只使用Javascript在点击时显示/隐藏选项卡,但我遇到了错误("Unaught TypeError:无法设置未定义选项卡的属性"className"。(匿名函数).onclick")。有人能告诉我可能是什么问题吗?
<style>
a { text-decoration: none; }
li { list-style: none; }
li.selected { font-weight: bold; }
.panels div { display: none; }
.panels .selected { display: block; }
</style>
<div id="tabs" class="tabs">
<ul>
<li class="selected"><a href="javascript:;">One</a></li>
<li class=""><a href="javascript:;">Two</a></li>
<li class=""><a href="javascript:;">Three</a></li>
</ul>
</div>
<div id="panels" class="panels">
<div class="selected">This is panel one.</div>
<div class="">This is panel two.</div>
<div class="">This is panel three.</div>
</div>
<script>
var tabs = document.getElementById("tabs").getElementsByTagName("li");
var panels = document.getElementById("panels").getElementsByTagName("div");
for (var i = 0; i < tabs.length; i++) {
new function(i) {
tabs[i].onclick = function() {
tabs[i].className = panels[i].className = "selected";
for (var i = 0; i < panels.length; i++) {
tabs[i].className = panels[i].className = "";
}
}
}(i);
}
</script>
您的内部for循环有一个i变量,该变量与同名的outter变量for循环冲突。
在将单击的元素设置为"selected"之前,还应该从所有元素中删除选定的类。
尝试:
<script>
var tabs = document.getElementById("tabs").getElementsByTagName("li");
var panels = document.getElementById("panels").getElementsByTagName("div");
for (var i = 0; i < tabs.length; i++) {
new function(i) {
tabs[i].onclick = function() {
for (var j = 0; j < panels.length; j++) {
tabs[j].className = panels[j].className = "";
}
tabs[i].className = panels[i].className = "selected";
}
}(i);
}
</script>
您遇到了几个问题:
- 多个
i
变量 new function(i) {...}
不是最好的语法。我使用了下面的闭包- 每行多个作业不好
我给了你的<li>
元素值,这样我们就可以判断哪个li元素被点击了
var tabs = document.getElementById("tabs").getElementsByTagName("li");
var panels = document.getElementById("panels").getElementsByTagName("div");
for (var i = 0; i < panels.length; i++) {
(function(i) {
tabs[i].onclick = function() {
var j;
var panelIndex;
// remove styles from other tabs
for (j = 0; j < tabs.length; j++) {
tabs[j].className = "";
}
// apply style to the current tab: 'this'
this.className = "selected";
// hide other panels
for (j = 0; j < panels.length; j++) {
panels[j].className = "";
}
// show the selected panel
panelIndex = +this.value; // convert value to number
panels[panelIndex-1].className="selected"; // arrays are 0-indexed, so subtract 1
}
})(i);
}
a { text-decoration: none; }
li { list-style: none; }
li.selected { font-weight: bold; }
.panels div { display: none; }
.panels .selected { display: block; }
<div id="tabs" class="tabs">
<ul>
<li value="1" class="selected"><a href="javascript:;">One</a></li>
<li value="2" class=""><a href="javascript:;">Two</a></li>
<li value="3" class=""><a href="javascript:;">Three</a></li>
</ul>
</div>
<div id="panels" class="panels">
<div class="selected">This is panel one.</div>
<div class="">This is panel two.</div>
<div class="">This is panel three.</div>
</div>
正如您所期望的那样,下面的内容将起作用。我在访问for循环中的HTML元素时发现了两个问题,您需要使用.item()作为它的HTMLCollection,而不是数组。此外,您的内部for循环需要使用不同的循环索引,并添加一个额外的if条件,使单击的一个保持如图所示,其余隐藏。
<style>
a { text-decoration: none; }
li { list-style: none; }
li.selected { font-weight: bold; }
.panels div { display: none; }
.panels .selected { display: block; }
</style>
<div id="tabs" class="tabs">
<ul>
<li class="selected"><a href="javascript:;">One</a></li>
<li class=""><a href="javascript:;">Two</a></li>
<li class=""><a href="javascript:;">Three</a></li>
</ul>
</div>
<div id="panels" class="panels">
<div class="selected">This is panel one.</div>
<div class="">This is panel two.</div>
<div class="">This is panel three.</div>
</div>
<script>
var tabs = document.getElementById("tabs").getElementsByTagName("li");
var panels = document.getElementById("panels").getElementsByTagName("div");
for (var i = 0; i < tabs.length; i++) {
new function(i) {
tabs[i].onclick = function() {
tabs.item(i).className = panels.item(i).className = "selected";
for (var j = 0; j < panels.length; j++) {
if(i!=j){
tabs.item(j).className = panels.item(j).className = "";
}
}
}
}(i);
}
</script>