方法有两种。 第一种通过<select>的属性来设置选中项,此方法可以在动态语言如php在后台根据需要控制输出结果。 1 2 3 4 5 | < select id = "sel" >
< option value = "1" >1</ option >
< option value = "2" selected = "selected" >2</ option >
< option value = "3" >3</ option >
</ select >
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第二种为通过前端js来控制选中的项: 由 www. 搜集整理 1 2 3 4 5 6 7 8 9 10 11 | < script type = "text/javascript" >
function change(){
document.getElementById("sel")[2].selected=true;
}
</ script >
< select id = "sel" >
< option value = "1" >1</ option >
< option value = "2" >2</ option >
< option value = "3" >3</ option >
</ select >
< input type = "button" value = "修改" onclick = "change()" />
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获取<select>标签选中项文本的js代码为: 1 2 | var val = document.all.Item.options[document.all.Item.selectedIndex].text
var i=document.getElementById( 'sel' ).options[document.getElementById( 'sel' ).selectedIndex].value;
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一些其它操作<select>标签的技巧如下: 1)动态创建select 1 2 3 4 5 | function createSelect(){
var mySelect = document.createElement( "select" );
mySelect.id = "mySelect" ;
document.body.appendChild(mySelect);
}
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2)添加选项option 1 2 3 4 5 6 | function addOption(){
var obj=document.getElementById( 'mySelect' );
obj.add( new Option( "文本" , "值" ));
}
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3)删除所有选项option 1 2 3 4 | function removeAll(){
var obj=document.getElementById( 'mySelect' );
obj.options.length=0;
}
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4)删除一个选项option 1 2 3 4 5 6 | function removeOne(){
var obj=document.getElementById( 'mySelect' );
var index=obj.selectedIndex;
obj.options.remove(index);
}
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5)获得选项option的值 1 2 3 | var obj=document.getElementById( 'mySelect' );
var index=obj.selectedIndex;
var val = obj.options[index].value;
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6)获得选项option的文本 1 2 3 | var obj=document.getElementById( 'mySelect' );
var index=obj.selectedIndex;
var val = obj.options[index].text;
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7)修改选项option 1 2 3 | var obj=document.getElementById( 'mySelect' );
var index=obj.selectedIndex;
var val = obj.options[index]= new Option( "新文本" , "新值" );
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8)删除select 1 2 3 4 | function removeSelect(){
var mySelect = document.getElementById( "mySelect" );
mySelect.parentNode.removeChild(mySelect);
}
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