String擴充 讓你在PadLeft和PadRight時不再受單雙位元組問題困擾，padleftpadright

String擴充 讓你在PadLeft和PadRight時不再受單雙位元組問題困擾，padleftpadright

因為在NET中，string的Length並不區分當前字串包含的字元為單位元組還是雙位元組字元，這樣導致我們在通過字串的PadLeft和PadRight方法處理一些需要排版顯示的字串時，會使得相關顯示參差不齊，所以這裡就有了這麼一個擴充，讓雙位元組顯示佔用的兩個單位元組寬度“吐”出來，下面是具體代碼

    using System.Text.RegularExpressions;    public static class StringExtensions    {        /// <summary>        /// 按單位元組字串向左填充長度        /// </summary>        /// <param name="input"></param>        /// <param name="length"></param>        /// <param name="paddingChar"></param>        /// <returns></returns>        public static string PadLeftWhileDouble(this string input, int length, char paddingChar = '\0')        {            var singleLength = GetSingleLength(input);            return input.PadLeft(length - singleLength + input.Length, paddingChar);         }        private static int GetSingleLength(string input)        {            if (string.IsNullOrEmpty(input))            {                throw new ArgumentNullException();            }            return Regex.Replace(input, @"[^\x00-\xff]", "aa").Length;//計算得到該字串對應單位元組字串的長度        }        /// <summary>        /// 按單位元組字串向右填充長度        /// </summary>        /// <param name="input"></param>        /// <param name="length"></param>        /// <param name="paddingChar"></param>        /// <returns></returns>        public static string PadRightWhileDouble(this string input, int length, char paddingChar = '\0')        {            var singleLength = GetSingleLength(input);            return input.PadRight(length - singleLength + input.Length, paddingChar);        }    }

測試代碼如下

            Console.WriteLine("123測試測試".PadRightWhileDouble(25) + "1");            Console.WriteLine("123測試測試".PadRightWhileDouble(25, 'A') + "1");            Console.WriteLine("1231212".PadRightWhileDouble(25) + "1");            Console.WriteLine("1231212".PadRightWhileDouble(25, 'A') + "1");            Console.WriteLine("123測試測試".PadLeftWhileDouble(25) + "1");            Console.WriteLine("123測試測試".PadLeftWhileDouble(25, 'A') + "1");            Console.WriteLine("1231212".PadLeftWhileDouble(25) + "1");            Console.WriteLine("1231212".PadLeftWhileDouble(25, 'A') + "1");

測試