php获取字符串宽度。

/**
 * 获取字符串宽度，半角字符1＝1，非半角角字符1＝2
 * @param string $str
 * @return float|int
 */
function strwidth($str) {
    $charcount = mb_strlen($str, 'utf-8');
    $pattern = '/[[:print:][:space:]]/u';
    $halfcount = 0;
    if (preg_match_all($pattern, $str, $_match)) {
        $halfcount = sizeof($_match[0]);
    }
    return $halfcount + ($charcount - $halfcount) * 2;
}