using System;

using System.Text;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        var strNum = "123";

        var strAlp = "aBc";

        var strMarks ="~,@";

        var strBig5 = "測試中文";

        var strMix = "12測a試B@";

        var strDiff = "詹éʉ小壡Ｏ？abcD";//"ABCDedf";//"八旗工程";//"詹小壡";//"无竜A龟";//无竜A龟";

        var strEncode =  "UTF-8"; //"big5";//"Default";// "UTF-8"; //

        // Console.WriteLine("{0}{1}", padRightEx(s1, 10), "end");

       // Console.WriteLine("{0}{1}", padRightEx(strNum, 10), "end");

       // Console.WriteLine("{0}{1}", padRightEx(strAlp, 10), "end");

      //  Console.WriteLine("{0}{1}", padRightEx(strMarks, 10), "end");

        //  Console.WriteLine("{0}{1}", padRightEx(strBig5, 10), "end");

      //  Console.WriteLine("{0}{1}", padRightEx(strMix, 10), "end");

          Console.WriteLine("{0}{1}", padRightEx(strDiff, 10), "end");

       // Console.WriteLine("{0}{1}", padRightEx(s2, 10), "end");

        // Console.WriteLine("{0}{1}", padRightEx(s1, 10, strEncode), "end");

       // Console.WriteLine("{0}{1}", padRightEx(strNum, 10, strEncode), "end");

       // Console.WriteLine("{0}{1}", padRightEx(strAlp, 10, strEncode), "end");

      //  Console.WriteLine("{0}{1}", padRightEx(strMarks, 10, strEncode), "end");

        //  Console.WriteLine("{0}{1}", padRightEx(strBig5, 10, strEncode), "end");

      //  Console.WriteLine("{0}{1}", padRightEx(strMix, 10, strEncode), "end");

          Console.WriteLine("{0}{1}", padRightEx_bak(strDiff, 10, strEncode), "end");

       // Console.WriteLine("{0}{1}", padRightEx(s2, 10, strEncode), "end");

​

    }

    private static string padRightEx(string str, int totalByteCount )

    {

        var intBig5Cnt = 0;

        var intCurrentByte = 0;

        var replaceChar = "Ｏ";

        var currChByte = 0;

        var currChar = "";

        var big5Char = "";

        var ascii = 0;

        StringBuilder sbResult = new StringBuilder();

        Encoding coding;

        // BIG5

        coding = CodePagesEncodingProvider.Instance.GetEncoding("big5");    

​

        // 計算以Big5取值需要幾個Byte

        foreach (char ch in str.ToCharArray())

        {   

            currChByte = 0;                 // reset

            currChar = ch.ToString();       

            big5Char = coding.GetString(coding.GetBytes(currChar));

            ascii = Convert.ToInt32(ch);

            // replaceChar取代問號及空白（ascii 32 = 半形空白）

            if ( big5Char == "?" || big5Char == "？" || ascii == 32 || big5Char == "？") {

                currChar = replaceChar; 

            }

            currChByte = coding.GetByteCount(currChar);     // replace後的Byte

            // 判斷是否超出byte

            if  ( ( intCurrentByte + currChByte ) <= totalByteCount ) {

                if ( currChByte > 1 ) {

                    intBig5Cnt++;                   // 計算幾個全形字

                }

                intCurrentByte = intCurrentByte + currChByte;

                sbResult.Append(currChar);          

            }

            else {

                break;  

            }

        }

​

        Console.WriteLine("PadRight:" + sbResult.ToString().PadRight( totalByteCount - intBig5Cnt )  + "end");

        Console.WriteLine(" PadLeft:" + sbResult.ToString().PadLeft( totalByteCount - intBig5Cnt)    + "end");

        return sbResult.ToString().PadRight( totalByteCount - intBig5Cnt );

    }  

    private static string padRightEx_bak(string str, int totalByteCount, string strEncode )

    {

​

        var intBig5Cnt = 0;

        var intCurrentByte = 0;

        Encoding coding;

        Encoding codeBig5 = CodePagesEncodingProvider.Instance.GetEncoding("big5");

        if ( strEncode.ToUpper() == "BIG5" )

            coding = CodePagesEncodingProvider.Instance.GetEncoding("big5");

        else 

            coding = Encoding.Default;// Encoding.GetEncoding(strEncode);

​

        // 計算以Big5取值需要幾個Byte

        foreach (char ch in str.ToCharArray())

        {   

            var intChByte = coding.GetByteCount(ch.ToString());

​

            if ( intChByte > 1 ) {

                if ( ( intCurrentByte + intChByte - intBig5Cnt - 1  ) > totalByteCount )        // 現在統計的Byte + 目前計算的字元 - 幾個非英數（big5算法）- 新增一個非英數 

                    break;

                intBig5Cnt++;                   // 加非英數字

            }

​

            intCurrentByte = intCurrentByte + intChByte;    

        }

​

​

        var byteArray = coding.GetBytes(str).Take( intCurrentByte ).ToList();           // linq 也是UTF-8 算法

        Console.WriteLine("PadRight:" + coding.GetString(byteArray.ToArray()).PadRight( totalByteCount - intBig5Cnt )  + "end");

        Console.WriteLine(" PadLeft:"  + coding.GetString(byteArray.ToArray()).PadLeft( totalByteCount - intBig5Cnt )   + "end");

        return coding.GetString(byteArray.ToArray()).PadRight( totalByteCount - intBig5Cnt );

​

    }  

}

​

​