织梦教程：重新定义cn_substr函数使截取字数更准确

织梦教程：重新定义cn_substr函数使截取字数更准确 打开 include/helpers/string.helper.php 文件，找到如下代码（大约33到102行）


if ( ! function_exists('cn_substr'))
{
    function cn_substr($str, $slen, $startdd=0)
    {
        global $cfg_soft_lang;
        if($cfg_soft_lang=='utf-8')
        {
            return cn_substr_utf8($str, $slen, $startdd);
        }
        $restr = '';
        $c = '';
        $str_len = strlen($str);
        if($str_len < $startdd+1)
        {
            return '';
        }
        if($str_len < $startdd + $slen || $slen==0)
        {
            $slen = $str_len - $startdd;
        }
        $enddd = $startdd + $slen - 1;
        for($i=0;$i<$str_len;$i++)
        {
            if($startdd==0)
            {
                $restr .= $c;
            }
            else if($i > $startdd)
            {
                $restr .= $c;
            }

            if(ord($str[$i])>0x80)
            {
                if($str_len>$i+1)
                {
                    $c = $str[$i].$str[$i+1];
                }
                $i++;
            }
            else
            {
                $c = $str[$i];
            }

            if($i >= $enddd)
            {
                if(strlen($restr)+strlen($c)>$slen)
                {
                    break;
                }
                else
                {
                    $restr .= $c;
                    break;
                }
            }
        }
        return $restr;
    }
}

替换为


if ( ! function_exists(‘cn_substr’)){
function cn_substr($str, $cutLen, $oDot = null, $hasHtml = false, $cutSlashes = false, $addSlashes = false) {
global $cfg_soft_lang;
$str = trim ( $str );
if ($cutSlashes) $str = stripslashes ( $str );
if($hasHtml){
$str = preg_replace ( “/(<[^<]*>|r|n|s|[.+?])/is”, ‘ ‘, $str );
$str = htmlspecialchars ( $str );
}else{
$str = htmlspecialchars ( $str );
}
if ($cutLen && strlen ( $str ) > $cutLen) {
$nStr = ”;
if ($cfg_soft_lang == ‘utf-8′) {
$n = 0;
$tn = 0;
$noc = 0;
while ( $n < strlen ( $str ) ) {
$t = ord ( $str [$n] );
if ($t == 9 || $t == 10 || (32 <= $t && $t <= 126)) {
$tn = 1;
$n ++;
$noc ++;
} elseif (194 <= $t && $t <= 223) {
$tn = 2;
$n += 2;
$noc += 2;
} elseif (224 <= $t && $t < 239) {
$tn = 3;
$n += 3;
$noc += 2;
} elseif (240 <= $t && $t <= 247) {
$tn = 4;
$n += 4;
$noc += 2;
} elseif (248 <= $t && $t <= 251) {
$tn = 5;
$n += 5;
$noc += 2;
} elseif ($t == 252 || $t == 253) {
$tn = 6;
$n += 6;
$noc += 2;
} else {
$n ++;
}
if ($noc >= $cutLen)break;
}
if ($noc > $cutLen) $n -= $tn;
$nStr = substr ( $str, 0, $n );
} else {
for($i = 0; $i < $cutLen – 1; $i ++) {
if (ord ( $str [$i] ) > 127) {
$nStr .= $str [$i] . $str [$i + 1];
$i ++;
} else {
$nStr .= $str [$i];
}
}
}
$str = $nStr . $oDot;
}
if ($addSlashes) $str = addslashes ( $str );
$str = htmlspecialchars_decode ( $str );
return trim ( $str );
}
}

修改后全站都可以使用cn_substr()函数，不管你的程序编码是gbk还是utf8

示例：调用10个字（拼音汉字混杂）
[field:title function='cn_substr(@me,20)']