String扩展 让你在PadLeft和PadRight时不再受单双字节问题困扰

标签：扩展   string   

因为在NET中，string的Length并不区分当前字符串包含的字符为单字节还是双字节字符，这样导致我们在通过字符串的PadLeft和PadRight方法处理一些需要排版显示的字符串时，会使得相关显示参差不齐，所以这里就有了这么一个扩展，让双字节显示占用的两个单字节宽度“吐”出来，下面是具体代码

    using System.Text.RegularExpressions;
    public static class StringExtensions
    {
        /// <summary>
        /// 按单字节字符串向左填充长度
        /// </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;//计算得到该字符串对应单字节字符串的长度
        }
        /// <summary>
        /// 按单字节字符串向右填充长度
        /// </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);
        }
    }

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

String扩展 让你在PadLeft和PadRight时不再受单双字节问题困扰

标签：扩展   string   

原文地址：http://blog.csdn.net/starfd/article/details/45895241