如何在网页上实现进度条

进度条的实现可以通过下面的javascript实现：

<table align="center"><tr><td>

<div style="font-size:8pt;padding:2px;border:solid black 1px">

<span id="progress1">&nbsp; &nbsp;</span>

<span id="progress2">&nbsp; &nbsp;</span>

<span id="progress3">&nbsp; &nbsp;</span>

<span id="progress4">&nbsp; &nbsp;</span>

<span id="progress5">&nbsp; &nbsp;</span>

<span id="progress6">&nbsp; &nbsp;</span>

<span id="progress7">&nbsp; &nbsp;</span>

<span id="progress8">&nbsp; &nbsp;</span>

<span id="progress9">&nbsp; &nbsp;</span>

</div>

</td></tr></table>

<script language="javascript">

var progressEnd = 9; // set to number of progress <span>'s.

var progressColor = 'blue'; // set to progress bar color

var progressInterval = 1000; // set to time between updates (milli-seconds)

var progressAt = progressEnd;

var progressTimer;

function progress_clear() {

for (var i = 1; i <= progressEnd; i++) document.getElementById('progress'+i).style.backgroundColor = 'transparent';

progressAt = 0;

}

function progress_update() {

progressAt++;

if (progressAt > progressEnd) progress_clear();

else document.getElementById('progress'+progressAt).style.backgroundColor = progressColor;

progressTimer = setTimeout('progress_update()',progressInterval);

}

function progress_stop() {

clearTimeout(progressTimer);

progress_clear();

}

progress_update(); // start progress bar

</script>

实现的原理就是通过修改spanid的backgroundColor 值和setTimeout('progress_update()',progressInterval);

定时器函数来实现的。