我有两个选择列表框，我可以使用前进（->）和后退（但是，如果选择列表中没有项目，则水平缩小尺寸。无论选择列表是否包含任何选项，如何将选择列表保持固定大小？
下面是代码：
<html>
<head>
<script language="JavaScript" type="text/javascript">
<!--
var NS4 = (navigator.appName == "Netscape" && parseInt(navigator.appVersion) < 5);
function addOption(theSel, theText, theValue)
{
var newOpt = new Option(theText, theValue);
var selLength = theSel.length;
theSel.options[selLength] = newOpt;
}
function deleteOption(theSel, theIndex)
{
var selLength = theSel.length;
if(selLength>0)
{
theSel.options[theIndex] = null;
}
}
function moveOptions(theSelFrom, theSelTo)
{
var selLength = theSelFrom.length;
var selectedText = new Array();
var selectedValues = new Array();
var selectedCount = 0;
var i;
// Find the selected Options in reverse order
// and delete them from the 'from' Select.
for(i=selLength-1; i>=0; i--)
{
if(theSelFrom.options[i].selected)
{
selectedText[selectedCount] = theSelFrom.options[i].text;
selectedValues[selectedCount] = theSelFrom.options[i].value;
deleteOption(theSelFrom, i);
selectedCount++;
}
}
// Add the selected text/values in reverse order.
// This will add the Options to the 'to' Select
// in the same order as they were in the 'from' Select.
for(i=selectedCount-1; i>=0; i--)
{
addOption(theSelTo, selectedText[i], selectedValues[i]);
}
if(NS4) history.go(0);
}
//-->
</script>
</head>
<body>
<form action="yourpage.asp" method="post">
<table border="0">
<tr>
<td width="70">
<select name="sel1" size="10" multiple="multiple">
<option value="1">Left1</option>
<option value="2">Left2</option>
<option value="3">Left3</option>
<option value="4">Left4</option>
<option value="5">Left5</option>
</select>
</td>
<td align="center" valign="middle">
<input type="button" value="-->"
onclick="moveOptions(this.form.sel1, this.form.sel2);" /><br />
<input type="button" value="<--"
onclick="moveOptions(this.form.sel2, this.form.sel1);" />
</td>
<td>
<select name="sel2" size="10" multiple="multiple">
<option value="1">Right1</option>
<option value="2">Right2</option>
<option value="3">Right3</option>
<option value="4">Right4</option>
<option value="5">Right5</option>
</select>
</td>
</tr>
</table>
</form>
</body>
</html>
最佳答案
将最小宽度属性应用于它们。
例如：
<select name="sel1" size="10" multiple="multiple" style="min-width: 200px;">
关于javascript - 选择列表为空时水平缩小，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/2750697/