select

一些Select的技巧

1.动态创建select

function createSelect(){

var mySelect = document.createElement("select"); 
mySelect.id = "mySelect"; 
document.body.appendChild(mySelect);
}

2.添加选项option

function addOption(){

//根据id查找对象，
var obj=document.getElementById('mySelect');

//添加一个选项
obj.add(new Option("文本","值")); 
}

3.删除所有选项option

function removeAll(){
var obj=document.getElementById('mySelect');

obj.options.length=0;

}

4.删除一个选项option

function removeOne(){
var obj=document.getElementById('mySelect');

//index,要删除选项的序号，这里取当前选中选项的序号

var index=obj.selectedIndex;
obj.options.remove(index); 
}

5.获得选项option的值

var obj=document.getElementById('mySelect');

var index=obj.selectedIndex; //序号，取当前选中选项的序号

var val = obj.options[index].value;

6.获得选项option的文本

var obj=document.getElementById('mySelect');

var index=obj.selectedIndex; //序号，取当前选中选项的序号

var val = obj.options[index].text;

7.修改选项option

var obj=document.getElementById('mySelect');

var index=obj.selectedIndex; //序号，取当前选中选项的序号

var val = obj.options[index]=new Option("新文本","新值");

8.删除select

function removeSelect(){
var mySelect = document.getElementById("mySelect");
mySelect.parentNode.removeChild(mySelect);
}

9.设置select optin被中