在开发的过程中经常会用到字符串截图，

尤其是中文很是头疼，给大家提供一个中文的截取方法。

//字符截断,中文算2个字符
function newstr($string, $length, $dot="...") {
	if(strlen($string) <= $length) {return $string;}
	$string = str_replace(array('&amp;', '&quot;', '&lt;', '&gt;'), array('&','"','<','>'), $string);
	$strcut = '';$n = $tn = $noc = $noct = $nc = $tnc =0;
	while($n < strlen($string)) {
		$t = ord($string[$n]);
		if($t == 9 || $t == 10 || (32 <= $t && $t <= 126)) {
			$tn = 1; $n++; $noct++;
		} elseif(194 <= $t && $t <= 223) {
			$tn = 2; $n += 2; $noct += 2;
		} elseif(224 <= $t && $t <= 239) {
			$tn = 3; $n += 3; $noct += 2;
		} elseif(240 <= $t && $t <= 247) {
			$tn = 4; $n += 4; $noct += 2;
		} elseif(248 <= $t && $t <= 251) {
			$tn = 5; $n += 5; $noct += 2;
		} elseif($t == 252 || $t == 253) {
			$tn = 6; $n += 6; $noct += 2;
		} else {$n++;}
		if($noct >= $length){if($noct==0)$noc=$noct;if($nc==0)$nc=$n;if($tnc==0)$tnc=$tn;}
	}
	if($noct<=$length){return str_replace(array('&','"','<','>'), array('&amp;', '&quot;', '&lt;', '&gt;'), $string);}
	if($noc > $length) {$nc -= $tnc;}
	$strcut = substr($string, 0, $nc);
	$strcut = str_replace(array('&','"','<','>'), array('&amp;', '&quot;', '&lt;', '&gt;'), $strcut);
	return $strcut.$dot;
}

好不好用可以试试，我觉得还不错。