I('变量类型.变量名/修饰符',    \['默认值'\],    \['过滤方法'\],    \['额外数据源'\]) I('post.') I('get.') [过滤](http://document.thinkphp.cn/manual_3_2.html#input_filter) I 函数本身默认的过滤机制是 htmlspecialchars，因为在配置文件中配置了： ~~~ // 系统默认的变量过滤机制 'DEFAULT_FILTER' => 'htmlspecialchars' //我们可以加点别的：如 ~~~ ~~~ 'DEFAULT_FILTER' => 'htmlspecialchars,trim' ~~~ // 采用htmlspecialchars方法对$\_GET\['name'\] 进行过滤，如果不存在则返回空字符串 echo I('get.name',  '',  'htmlspecialchars'); 3.2.3版本开始，I函数支持对变量使用修饰符功能，可以更好的过滤变量。 I('get.id/d'); I('post.name/s'); I('post.ids/a'); ~~~ 修饰符 作用 s 强制转换为字符串类型 d 强制转换为整形类型 （注意不能超过10位数） b 强制转换为布尔类型 a 强制转换为数组类型 f 强制转换为浮点类型 ~~~ 如果是富文本时不过滤（比如：I('content','',null);）然后手动过滤：  [](javascript:void(0); "复制代码") ~~~ //过滤XSS攻击 function reMoveXss($val) { // remove all non-printable characters. CR(0a) and LF(0b) and TAB(9) are allowed // this prevents some character re-spacing such as <java\0script> // note that you have to handle splits with \n, \r, and \t later since they *are* allowed in some inputs $val = preg_replace('/([\x00-\x08,\x0b-\x0c,\x0e-\x19])/', '', $val); // straight replacements, the user should never need these since they're normal characters // this prevents like <IMG SRC=@avascript:alert('XSS')> $search = 'abcdefghijklmnopqrstuvwxyz'; $search .= 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'; $search .= '1234567890!@#$%^&*()'; $search .= '~`";:?+/={}[]-_|\'\\'; for ($i = 0; $i < strlen($search); $i++) { // ;? matches the ;, which is optional // 0{0,7} matches any padded zeros, which are optional and go up to 8 chars // @ @ search for the hex values $val = preg_replace('/(&#[xX]0{0,8}' . dechex(ord($search[$i])) . ';?)/i', $search[$i], $val); // with a ; // @ @ 0{0,7} matches '0' zero to seven times $val = preg_replace('/(&#0{0,8}' . ord($search[$i]) . ';?)/', $search[$i], $val); // with a ; } // now the only remaining whitespace attacks are \t, \n, and \r $ra1 = Array('javascript', 'vbscript', 'expression', 'applet', 'meta', 'xml', 'blink', 'script', 'embed', 'object', 'iframe', 'frameset', 'ilayer', 'layer', 'bgsound', 'base'); $ra2 = Array('onabort', 'onactivate', 'onafterprint', 'onafterupdate', 'onbeforeactivate', 'onbeforecopy', 'onbeforecut', 'onbeforedeactivate', 'onbeforeeditfocus', 'onbeforepaste', 'onbeforeprint', 'onbeforeunload', 'onbeforeupdate', 'onblur', 'onbounce', 'oncellchange', 'onchange', 'onclick', 'oncontextmenu', 'oncontrolselect', 'oncopy', 'oncut', 'ondataavailable', 'ondatasetchanged', 'ondatasetcomplete', 'ondblclick', 'ondeactivate', 'ondrag', 'ondragend', 'ondragenter', 'ondragleave', 'ondragover', 'ondragstart', 'ondrop', 'onerror', 'onerrorupdate', 'onfilterchange', 'onfinish', 'onfocus', 'onfocusin', 'onfocusout', 'onhelp', 'onkeydown', 'onkeypress', 'onkeyup', 'onlayoutcomplete', 'onload', 'onlosecapture', 'onmousedown', 'onmouseenter', 'onmouseleave', 'onmousemove', 'onmouseout', 'onmouseover', 'onmouseup', 'onmousewheel', 'onmove', 'onmoveend', 'onmovestart', 'onpaste', 'onpropertychange', 'onreadystatechange', 'onreset', 'onresize', 'onresizeend', 'onresizestart', 'onrowenter', 'onrowexit', 'onrowsdelete', 'onrowsinserted', 'onscroll', 'onselect', 'onselectionchange', 'onselectstart', 'onstart', 'onstop', 'onsubmit', 'onunload'); $ra = array_merge($ra1, $ra2); $found = true; // keep replacing as long as the previous round replaced something while ($found == true) { $val_before = $val; for ($i = 0; $i < sizeof($ra); $i++) { $pattern = '/'; for ($j = 0; $j < strlen($ra[$i]); $j++) { if ($j > 0) { $pattern .= '('; $pattern .= '(&#[xX]0{0,8}([9ab]);)'; $pattern .= '|'; $pattern .= '|(&#0{0,8}([9|10|13]);)'; $pattern .= ')*'; } $pattern .= $ra[$i][$j]; } $pattern .= '/i'; $replacement = substr($ra[$i], 0, 2) . '<x>' . substr($ra[$i], 2); // add in <> to nerf the tag $val = preg_replace($pattern, $replacement, $val); // filter out the hex tags if ($val_before == $val) { // no replacements were made, so exit the loop $found = false; } } } return $val; } ~~~