我们在进行页面跳转的时候，通常会用到
在PHP中用header("location:test.php")进行跳转要注意以下几点,有助于解决一些新手经常遇到的问题
1、location和“:”号间不能有空格，否则会出错。
2、在用header前不能有任何的输出。
3、header后的PHP代码还会被执行。
下面是和asp中重定向response.redirect的比较：
例1:
response.redirect "../test.asp"
header("location:../test.php");
两者区别:
asp的redirect函数可以在向客户发送头文件后起作用.
如
<ol class="dp-xml"> <li class="alt"><span><span class="tag"><span class="tag-name">html</span><span class="tag">></span><span class="tag"><span class="tag-name">head</span><span class="tag">></span><span class="tag"><span class="tag-name">head</span><span class="tag">></span><span class="tag"><span class="tag-name">body</span><span class="tag">></span><span> </span></span></span></span></span></span></li> <li><span class="tag"><span>%response.redirect "../test.asp"%</span><span class="tag">></span><span> </span></span></li> <li class="alt"><span class="tag"><span class="tag-name">body</span><span class="tag">></span><span class="tag"><span class="tag-name">html</span><span class="tag">></span><span> </span></span></span></li> </ol>
查是php中下例代码会报错:
<ol class="dp-xml">
<li class="alt"><span><span class="tag"><span> </span><span class="tag-name">html</span><span class="tag">></span><span class="tag"><span> </span><span class="tag-name">head</span><span class="tag">></span><span class="tag"><span> /head</span><span class="tag">></span><span class="tag"><span> </span><span class="tag-name">body</span><span class="tag">></span><span> </span></span></span></span></span></span></li>
<li>
<span class="tag"></span><span> </span>
</li>
<li class="alt">
<span class="tag-name">header</span><span>("location:../test.php"); </span>
</li>
<li>
<span class="tag">?></span><span> </span>
</li>
<li class="alt"><span class="tag"><span> /body</span><span class="tag">></span><span class="tag"><span> /html</span><span class="tag">></span><span> </span></span></span></li>
<li><span>只能这样: </span></li>
<li class="alt"><span class="tag"><span> ? </span></span></li>
<li><span>header("location:../test.php"); </span></li>
<li class="alt">
<span class="tag">?></span><span> </span>
</li>
<li><span class="tag"><span> </span><span class="tag-name">html</span><span class="tag">></span><span class="tag"><span> </span><span class="tag-name">head</span><span class="tag">></span><span class="tag"><span> /head</span><span class="tag">></span><span class="tag"><span> </span><span class="tag-name">body</span><span class="tag">></span><span>...</span><span class="tag"><span> /body</span><span class="tag">></span><span class="tag"><span> /html</span><span class="tag">></span><span> </span></span></span></span></span></span></span></li>
</ol>即PHP header之前不能向客户发送任何数据.
例2:
asp中
<ol class="dp-xml">
<li class="alt"><span><span class="tag"><span> </span><span class="tag-name">html</span><span class="tag">></span><span class="tag"><span> </span><span class="tag-name">head</span><span class="tag">></span><span class="tag"><span> /head</span><span class="tag">></span><span class="tag"><span> </span><span class="tag-name">body</span><span class="tag">></span><span> </span></span></span></span></span></span></li>
<li><span class="tag"><span>% </span></span></li>
<li class="alt"><span>response.redirect "../a.asp" </span></li>
<li><span>response.redirect "../b.asp" </span></li>
<li class="alt">
<span>%</span><span class="tag">></span><span> </span>
</li>
<li><span class="tag"><span> /body</span><span class="tag">></span><span class="tag"><span> /html</span><span class="tag">></span><span> </span></span></span></li>
<li class="alt"><span>结果是重定向a.asp文件. </span></li>
<li><span>php呢? </span></li>
<li class="alt"><span class="tag"><span> ? </span></span></li>
<li><span>header("location:../a.php"); </span></li>
<li class="alt"><span>header("location:../b.php"); </span></li>
<li>
<span class="tag">?></span><span> </span>
</li>
<li class="alt"><span class="tag"><span> </span><span class="tag-name">html</span><span class="tag">></span><span class="tag"><span> </span><span class="tag-name">head</span><span class="tag">></span><span class="tag"><span> /head</span><span class="tag">></span><span class="tag"><span> </span><span class="tag-name">body</span><span class="tag">></span><span class="tag"><span> /body</span><span class="tag">></span><span class="tag"><span> /html</span><span class="tag">></span><span> </span></span></span></span></span></span></span></li>
</ol>我们发现它重定向b.php.
原来在asp中执行redirect后不会再执行后面的代码.
而php在执行header后,继续执行下面的代码.
在这方面上php中的header重定向不如asp中的重定向.有时我们要重定向后,不能执行后面的代码:
一般地我们用
<ol class="dp-xml">
<li class="alt"><span><span>if(...) </span></span></li>
<li><span>header("..."); </span></li>
<li class="alt"><span>else </span></li>
<li><span>{ </span></li>
<li class="alt"><span>... </span></li>
<li><span>} </span></li>
</ol>但是我们可以简单的用下面的PHP header方法:
<ol class="dp-xml">
<li class="alt"><span><span>if(...) </span></span></li>
<li><span>{ header("...");exit();} </span></li>
</ol>还要注意的是，如果是用Unicode(UTF-8)编码时也会出现问题，需要调整PHP header的缓存设置.
<ol class="dp-xml">
<li class="alt"><span><span class="tag"><span> [</span><span class="attribute">email</span><span>=%@]%@</span><span class="attribute">LANGUAGE</span><span>=</span><span class="attribute-value">"VBSCRIPT[/email]"</span><span> </span><span class="attribute">CODEPAGE</span><span>=</span><span class="attribute-value">"936"</span><span>%</span><span class="tag">></span><span> </span></span></span></li>
<li><span class="tag"><span> %if Request.ServerVariables("SERVER_NAME")="s.jb51.net" then </span></span></li>
<li class="alt"><span>response.redirect "news/index.htm" </span></li>
<li>
<span>else%</span><span class="tag">></span><span> </span>
</li>
<li class="alt"><span class="tag"><span> %end if%</span><span class="tag">></span><span> </span></span></li>
<li><span class="tag"><span> </span><span class="tag-name">script</span><span class="tag">></span><span> </span></span></li>
<li class="alt">
<span>var </span><span class="attribute">url</span><span> = </span><span class="attribute-value">location</span><span>.href; </span>
</li>
<li>
<span>if(url.indexOf('http://www.jb51.net/')!=-1)</span><span class="attribute">location.href</span><span>=</span><span class="attribute-value">'/index/index.htm'</span><span>; </span>
</li>
<li class="alt">
<span>if(url.indexOf('http://www.kanshule.com/')!=-1)</span><span class="attribute">location.href</span><span>=</span><span class="attribute-value">'/index1/index.htm'</span><span>; </span>
</li>
<li>
<span>if(url.indexOf('http://www.shouji17.com/')!=-1)</span><span class="attribute">location.href</span><span>=</span><span class="attribute-value">'/cn/index.asp'</span><span>; </span>
</li>
<li class="alt">
<span>if(url.indexOf('http://www.baidu.com/')!=-1)</span><span class="attribute">location.href</span><span>=</span><span class="attribute-value">'/cn/index.asp'</span><span>; </span>
</li>
<li><span class="tag"><span> /script</span><span class="tag">></span><span> </span></span></li>
</ol>以上就是在使用PHP header时应当注意的几点问题。
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