再次发问,有帮忙解决的另开帖再给100分

[whiteclude]

<xml id="xmldso">
<root>
<product>
<serial>08157</serial>
</product>
<product>
<serial>01005</serial>
</product>
<product>
<serial>36833</serial>
</product>
<product>
<serial>39949</serial>
</product>
<product>
<serial>39893</serial>
</product>
<product>
<serial>32178</serial>
</product>
</root>
</xml>
<table datasrc="#xmldso">
<tr>
<td>
<select id="ser" datafld="serial">
<option value="08157">08157
<option value="01005">01005
<option value="36833">36833
<option value="39949">39949
<option value="39893">39893
<option value="32178">32178
</select>
</td>

</tr>
</table>
<input type="button" onclick="democlick()" value="demo">
<script>
function democlick() {
document.all.ser[0].length = 0;
alert(document.all.ser[0].length)
document.all.ser[0].options[0] = new Option("08157","08157");
alert(document.all.ser[0].length)
}
</script>

这样一段code,点击demo按钮,弹出的对话框数据和方法数据不一致,第二次弹出应该为1,结果却为2,奇怪

[孟子E章]

这样修改就没有问题了！有Bug是难免的，但总可以实现您的要求的：

document.all.ser[0].options[0] = new Option()
document.all.ser[0].options[0].value="08157"
document.all.ser[0].options[0].text="08157"

另外：第二参数换成别的值都是正确的

<xml id="xmldso">
<root>
<product>
<serial>08157</serial>
</product>
<product>
<serial>01005</serial>
</product>
<product>
<serial>36833</serial>
</product>
<product>
<serial>39949</serial>
</product>
<product>
<serial>39893</serial>
</product>
<product>
<serial>32178</serial>
</product>
</root>
</xml>
<table datasrc="#xmldso" id=tb>
<tr>
<td>
<select id="ser" datafld="serial">
<option value="08157">08157
<option value="01005">01005
<option value="36833">36833
<option value="39949">39949
<option value="39893">39893
<option value="32178">32178
</select>
</td>

</tr>
</table>
<input type="button" onclick="democlick()" value="demo">
<script>
function democlick() {
document.all.ser[0].length = 0;
alert(document.all.ser[0].length)
document.all.ser[0].options[0] = new Option()
document.all.ser[0].options[0].value="08157"
document.all.ser[0].options[0].text="08157"

alert(document.all.ser[0].length)
}
</script>

[whiteclude]

孟兄,谢了,另开帖再赠100