PHP中用header的具体使用技巧_PHP教程
- WBOY原创
- 2016-07-15 13:28:51812浏览
我们在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、PHP中用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><strong><font color="#006699"><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><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></font></strong><span> </span></span></li> <li class=""> <span></span><span class="tag"><strong><font color="#006699"></font></strong></span><span>%response.redirect "../test.asp"%</span><span class="tag"><strong><font color="#006699">></font></strong></span><span> </span> </li> <li class="alt"> <span></span><strong><font color="#006699"><span class="tag"></span><span class="tag-name">body</span><span class="tag">></span><span class="tag"></span><span class="tag-name">html</span><span class="tag">></span></font></strong><span> </span> </li> </ol>
查是PHP中用header中下例代码会报错:
<ol class="dp-xml">
<li class="alt"><span><strong><font color="#006699"><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><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></font></strong><span> </span></span></li>
<li class="">
<span></span><span class="tag"><strong><font color="#006699"></font></strong></span><span> </span>
</li>
<li class="alt">
<span></span><span class="tag-name"><strong><font color="#006699">header</font></strong></span><span>("location:../test.php"); </span>
</li>
<li class="">
<span></span><span class="tag"><strong><font color="#006699">?></font></strong></span><span> </span>
</li>
<li class="alt">
<span></span><strong><font color="#006699"><span class="tag"></span><span class="tag-name">body</span><span class="tag">></span><span class="tag"></span><span class="tag-name">html</span><span class="tag">></span></font></strong><span> </span>
</li>
</ol>
只能这样:
<ol class="dp-xml">
<li class="alt"><span><span class="tag"><strong><font color="#006699"></font></strong></span><span> </span></span></li>
<li class="">
<span></span><span class="tag-name"><strong><font color="#006699">header</font></strong></span><span>("location:../test.php"); </span>
</li>
<li class="alt">
<span></span><span class="tag"><strong><font color="#006699">?></font></strong></span><span> </span>
</li>
<li class="">
<span></span><strong><font color="#006699"><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><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></font></strong><span>...</span><strong><font color="#006699"><span class="tag"></span><span class="tag-name">body</span><span class="tag">></span><span class="tag"></span><span class="tag-name">html</span><span class="tag">></span></font></strong><span> </span>
</li>
</ol>
即PHP中用header函数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><strong><font color="#006699"><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><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></font></strong><span> </span></span></li> <li class=""> <span></span><span class="tag"><strong><font color="#006699"></font></strong></span><span>% </span> </li> <li class="alt"><span>response.redirect "../a.asp" </span></li> <li class=""><span>response.redirect "../b.asp" </span></li> <li class="alt"> <span>%</span><span class="tag"><strong><font color="#006699">></font></strong></span><span> </span> </li> <li class=""> <span></span><strong><font color="#006699"><span class="tag"></span><span class="tag-name">body</span><span class="tag">></span><span class="tag"></span><span class="tag-name">html</span><span class="tag">></span></font></strong><span> </span> </li> </ol>
结果是重定向a.asp文件.
php呢?
<ol class="dp-xml">
<li class="alt"><span><span class="tag"><strong><font color="#006699"></font></strong></span><span> </span></span></li>
<li class="">
<span></span><span class="tag-name"><strong><font color="#006699">header</font></strong></span><span>("location:../a.php"); </span>
</li>
<li class="alt"><span>header("location:../b.php"); </span></li>
<li class="">
<span></span><span class="tag"><strong><font color="#006699">?></font></strong></span><span> </span>
</li>
<li class="alt">
<span></span><strong><font color="#006699"><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><span class="tag-name">head</span><span class="tag">></span><span class="tag"><span class="tag-name">body</span><span class="tag">></span><span class="tag"></span><span class="tag-name">body</span><span class="tag">></span><span class="tag"></span><span class="tag-name">html</span><span class="tag">></span></span></span></span></font></strong><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 class=""><span>header("..."); </span></li>
<li class="alt"><span>else </span></li>
<li class=""><span>{ </span></li>
<li class="alt"><span>... </span></li>
<li class=""><span>} </span></li>
</ol>
但是我们可以简单的用下面的方法:
<ol class="dp-xml">
<li class="alt"><span><span>if(...) </span></span></li>
<li class=""><span>{ header("...");exit();} </span></li>
</ol>
PHP中用header还要注意的是，如果是用Unicode(UTF-8)编码时也会出现问题，需要调整缓存设置.
<ol class="dp-xml">
<li class="alt"><span><span class="tag"><strong><font color="#006699"></font></strong></span><span>[</span><span class="attribute"><font color="#ff0000">email</font></span><span>=%@]%@</span><span class="attribute"><font color="#ff0000">LANGUAGE</font></span><span>=</span><span class="attribute-value"><font color="#0000ff">"VBSCRIPT[/email]"</font></span><span> </span><span class="attribute"><font color="#ff0000">CODEPAGE</font></span><span>=</span><span class="attribute-value"><font color="#0000ff">"936"</font></span><span>%</span><span class="tag"><strong><font color="#006699">></font></strong></span><span> </span></span></li>
<li class="">
<span></span><span class="tag"><strong><font color="#006699"></font></strong></span><span>%if Request.ServerVariables("SERVER_NAME")="s.jb51.net" then </span>
</li>
<li class="alt"><span>response.redirect "news/index.htm" </span></li>
<li class="">
<span>else%</span><span class="tag"><strong><font color="#006699">></font></strong></span><span> </span>
</li>
<li class="alt">
<span></span><span class="tag"><strong><font color="#006699"></font></strong></span><span>%end if%</span><span class="tag"><strong><font color="#006699">></font></strong></span><span> </span>
</li>
<li class="">
<span></span><strong><font color="#006699"><span class="tag"><span class="tag-name">script</span><span class="tag">></span></span></font></strong><span> </span>
</li>
<li class="alt">
<span>var </span><span class="attribute"><font color="#ff0000">url</font></span><span> = </span><span class="attribute-value"><font color="#0000ff">location</font></span><span>.href; </span>
</li>
<li class="">
<span>if(url.indexOf('http://www.jb51.net/')!=-1)</span><span class="attribute"><font color="#ff0000">location.href</font></span><span>=</span><span class="attribute-value"><font color="#0000ff">'/index/index.htm'</font></span><span>; </span>
</li>
<li class="alt">
<span>if(url.indexOf('http://www.kanshule.com/')!=-1)</span><span class="attribute"><font color="#ff0000">location.href</font></span><span>=</span><span class="attribute-value"><font color="#0000ff">'/index1/index.htm'</font></span><span>; </span>
</li>
<li class="">
<span>if(url.indexOf('http://www.shouji17.com/')!=-1)</span><span class="attribute"><font color="#ff0000">location.href</font></span><span>=</span><span class="attribute-value"><font color="#0000ff">'/cn/index.asp'</font></span><span>; </span>
</li>
<li class="alt">
<span>if(url.indexOf('http://www.baidu.com/')!=-1)</span><span class="attribute"><font color="#ff0000">location.href</font></span><span>=</span><span class="attribute-value"><font color="#0000ff">'/cn/index.asp'</font></span><span>; </span>
</li>
<li class="">
<span></span><strong><font color="#006699"><span class="tag"></span><span class="tag-name">script</span><span class="tag">></span></font></strong><span> </span>
</li>
</ol> 声明：
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