function Button1_onclick() {
var a1=document.getElementById('b');
if(a1.innerHTML=="+"){
a1.innerHTML= "-";
document.getElementById('list').style.display= "block";
}
else{
a1.innerHTML= "+";
document.getElementById('list').style.display= "none";
}
}
<input id="Button1" type="button" value="button" onclick="return Button1_onclick()" />
<ul id="list">
<li>item1 </li>
<li> item2 </li>
<li> item3 </li>
</ul>
红色部分
var a1=document.getElementById('b');
if(a1.innerHTML=="+"){
a1.innerHTML= "-";
document.getElementById('list').style.display= "block";
}
else{
a1.innerHTML= "+";
document.getElementById('list').style.display= "none";
}
}
<input id="Button1" type="button" value="button" onclick="return Button1_onclick()" />
<ul id="list">
<li>item1 </li>
<li> item2 </li>
<li> item3 </li>
</ul>
红色部分
解决方案 »
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