WEB开发技术知识库

　　程序代码
cut_str(字符串, 截取长度, 开始长度, 编码);
编码默认为 utf-8
开始长度默认为 0
<?Php
/***************************************************************************
* cut_string.Php
* ------------------------------
* Date : Jul 16, 2005
* Copyright : none
* Mail :
*
* 作用:截取中文字符.
*
*
***************************************************************************/
function cut_str($string, $sublen, $start = 0, $code = 'UTF-8')
{
if($code == 'UTF-8')
{
$pa = "/[x01-x7f]|[xc2-xdf][x80-xbf]|xe0[xa0-xbf][x80-xbf]|[xe1-xef][x80-xbf][x80-xbf]|xf0[x90-xbf][x80-xbf][x80-xbf]|[xf1-xf7][x80-xbf][x80-xbf][x80-xbf]/";
preg_match_all($pa, $string, $t_string);
if(count($t_string[0]) - $start > $sublen) return join('', array_slice($t_string[0], $start, $sublen))."...";
return join('', array_slice($t_string[0], $start, $sublen));
}
else
{
$start = $start*2;
$sublen = $sublen*2;
$strlen = strlen($string);
$tmpstr = '';
for($i=0; $i<$strlen; $i++)
{
if($i>=$start && $i<($start+$sublen))
{
if(ord(substr($string, $i, 1))>129) $tmpstr.= substr($string, $i, 2);
else $tmpstr.= substr($string, $i, 1);
}
if(ord(substr($string, $i, 1))>129) $i++;
}
if(strlen($tmpstr)<$strlen ) $tmpstr.= "...";
return $tmpstr;
}
}
'---------截取指定长度的utf8字符串------------
'////str:string 源字符串
'//count:Integer 指定长度  一个汉字占三个字节,长度只能小,不能大
'//Result:string 截取后的utf8字符串
class function TPduPush.getUTF8String(Str: string; count: Integer): string;
var     i, j: integer;    
        tmpChar: Pchar;
begin    
        tmpChar := pchar(str);   
        i := 0;    
        j := 0;   
        result := ’’;   
        while i < length(tmpChar) do begin     
            if j >= count then break;  //英文转码后不能超过指定的位数     
                if ord(tmpChar) < $80 then begin            
                    result := result + string(tmpChar);           
                    i := i + 1;             
                    j := j + 1;         
                end
            else begin    
                if j + 2 >= count then break;  //汉字转码后不能超过指定的位数                       result := result + string(tmpChar) + string(tmpChar[i + 1]);
                    i := i + 2;     
                    j := j + 3;       
                end;   
            end;
end;
}