/** * 中英數字混合的字符串截取 * Param: 參數說明 * 【in】$sourcestr string 截取字符串 * 【in】$cutlength int 截取長度 */ public function assoc_substr($sourcestr, $cutlength) { $returnstr = ''; $i = 0; $n = 0; $str_length = strlen ( $sourcestr ); //字符串的字節數 while ( ($n < $cutlength) and ($i <= $str_length) ) { $temp_str = substr ( $sourcestr, $i, 1 ); $ascnum = Ord ( $temp_str ); //獲得字符串中第$i位字符的ascii碼 if ($ascnum >= 224) {//若是ASCII位高與224, $returnstr = $returnstr . substr ( $sourcestr, $i, 3 ); //根據UTF-8編碼規範,將3個連續的字符計爲單個字符 $i = $i + 3; //實際Byte計爲3 $n ++; //字串長度計1 } elseif ($ascnum >= 192){ //若是ASCII位高與192, $returnstr = $returnstr . substr ( $sourcestr, $i, 2 ); //根據UTF-8編碼規範,將2個連續的字符計爲單個字符 $i = $i + 2; //實際Byte計爲2 $n ++; //字串長度計1 } elseif ($ascnum >= 65 && $ascnum <= 90) {//若是是大寫字母, $returnstr = $returnstr . substr ( $sourcestr, $i, 1 ); $i = $i + 1; //實際的Byte數仍計1個 $n ++; //但考慮總體美觀,大寫字母計成一個高位字符 }elseif ($ascnum >= 97 && $ascnum <= 122) { $returnstr = $returnstr . substr ( $sourcestr, $i, 1 ); $i = $i + 1; //實際的Byte數仍計1個 $n ++; //但考慮總體美觀,大寫字母計成一個高位字符 }elseif($ascnum>=48 && $ascnum<=57){ $returnstr = $returnstr . substr ( $sourcestr, $i, 1 ); $n ++; //但考慮總體美觀,大寫字母計成一個高位字符 }else {//其餘狀況下,半角標點符號, $returnstr = $returnstr . substr ( $sourcestr, $i, 1 ); $i = $i + 1; $n = $n + 0.5; } } return $returnstr; }