建设一个简单交互的网站(五)
8. 投票系统
在许多时候，我们需要收集上网者和网友们的意见。例如：新版页面与旧版页面的比较；对某一事情的看法；对体育比赛结果的预测等等。这时候，你需要一个非常有效的网上调查系统。使用PHP就可以非常方便地实现你的这一构想。
8.1 投票系统（mypolls.php3）：
<?
$status=0;
if(isset($polled)&&($polled=="c-e")){
$status=1;
}
#echo "$status";
if(isset($poll)&&($status==0)){
setcookie("polled","c-e",time()+86400,"/");#time=24h
}
?>
<html>
<head>
<title>新版页面调查</title>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<style type="text/css">
<!--
.tb { border="1" bordercolor="#009933" cellspacing="0" font-size: 9pt; color: #000000}
.head { font-family: "宋体"; font-size: 12pt; font-weight: bold; color: #009933; text-decoration: none}
.pt9 { font-size: 9pt}
a.p9:link { font-size: 9pt; color: #000000; text-decoration: none}
a.p9:visited { font-size: 9pt; color: #000000; text-decoration: none }
a.p9:hover { font-size: 9pt; color: #FF0000; text-decoration: underline}
a.p9:active { font-size: 9pt; color: #FF0000; text-decoration: underline }
-->
</style>
</head>
<body bgcolor="#FFFFFF">
<div class="head">与旧版页面相比较您觉得新版页面：</div><br>
<?
if(!isset($submit)){
?>
<form action="myPolls.php3" method="get">
<input type="radio" name="poll_voteNr" ＆#118alue="1" checked >
<span class="pt9">信息量更大</span> <br>
<input type="radio" name="poll_voteNr" ＆#118alue="2" >
<span class="pt9">网页更精美</span> <br>
<input type="radio" name="poll_voteNr" ＆#118alue="3" >
<span class="pt9">没什么改进</span> <br>
<input type="radio" name="poll_voteNr" ＆#118alue="4" >
<span class="pt9">其它</span> <br>
<input type="submit" name="submit" ＆#118alue="OK">
<input type="hidden" name="poll" ＆#118alue="vote">
<A HREF="myPolls.php3?submit=OK" class="p9">查看调查结果</A>
</form>
<?
/*
如果想增加其它的选项可直接加上即可
*/
}else{
$descArray=array(1=>"信息量更大",
2=>"网页更精美",
3=>"没什么改进",
4=>"其它"
);
$poll_resultBarHeight = 9; // height in pixels of percentage bar in result table
$poll_resultBarScale = 1; // scale of result bar (in multiples of 100 pixels)
$poll_tableHeader="<table border=1 class="tb">";
$poll_rowHeader="<tr>";
$poll_dataHeader="<td align=center>";
$poll_dataFooter="</td>";
$poll_rowFooter="</tr>";
$poll_tableFooter="</table>";
$coutfile="data.pol";
$poll_sum=0;
// read counter-file
if (file_exists( $coutfile))
{
$fp = fopen( $coutfile, "rt");
while ($Line = fgets($fp, 10))
{
// split lines into identifier/counter
if (ereg( "([^ ]*) *([0-9]*)", $Line, $tmp))
{
$curArray[(int)$tmp[1]] = (int)$tmp[2];
$poll_sum+=(int)$tmp[2];
}
}
// close file
fclose($fp);
}else{//
for ($i=1;$i<=count($descArray);$i++){
$curArray[$i]=0;
}
}
if(isset($poll)){
$curArray[$poll_voteNr]++;
$poll_sum++;
}
echo $poll_tableHeader;
// cycle through all options编历数组
reset($curArray);
while (list($K, $V) = each($curArray))
{
$poll_optionText = $descArray[$K];
$poll_optionCount = $V;
echo $poll_rowHeader;
if($poll_optionText != "")
{
echo $poll_dataHeader;
echo $poll_optionText;
echo $poll_dataFooter;
if($poll_sum)
$poll_percent = 100 * $poll_optionCount / $poll_sum;
else
$poll_percent = 0;
echo $poll_dataHeader;
if ($poll_percent > 0)
{
$poll_percentScale = (int)($poll_percent * $poll_resultBarScale);
}
printf(" %.2f %% (%d)", $poll_percent, $poll_optionCount);
echo $poll_dataFooter;
}
echo $poll_rowFooter;
}
echo "总共投票次数:<font color=red> $poll_sum</font>";
echo $poll_tableFooter;
echo "<br>";
echo "<input type="submit" name="Submit1" ＆#118alue="返回主页" ＆#111nClick="javascript:location='http://gophp.heha.net/index.html'";>";
echo " <input type="submit" name="Submit2" ＆#118alue="重新投票" ＆#111nClick="javascript:location='http://gophp.heha.net/mypolls.php3'";>";
if(isset($poll)){
// write counter file
$fp = fopen($coutfile, "wt");
reset($curArray);
while (list($Key, $＆#118alue) = each($curArray))
{
$tmp = sprintf( "%s %dn", $Key, $＆#118alue);
fwrite($fp, $tmp);
}
// close file
fclose($fp);
}
}
?>
</body>
</html>
注释：从上面我们可以看出该投票系统的基本过程：
1、打开文件取得数据到数组$curArray（文件不存在则初始化数组$curArray）
2、编历数组，处理数据得到所需值
3、计算百分比，控制统计bar图像宽度
4、将数据保存到"data.pol"中
这里有一点是需要注意：这里的data.pol文本文件需要有写权限。
