Repair RealMedia Files

using System;
using System.Text;
using System.Collections.Generic;
using System.Text.RegularExpressions;

namespace QiHe.CodeLib
{
    /// <summary>
    /// StringHelper ��ժҪ˵����
    /// </summary>
    public class StringHelper
    {
        /// <summary>
        /// Concats two strings with a delimiter.
        /// </summary>
        /// <param name="s1">string 1</param>
        /// <param name="delim">delimiter</param>
        /// <param name="s2">string 2</param>
        /// <returns></returns>
        public static string AddWithDelim(string s1, string delim, string s2)
        {
            if (string.IsNullOrEmpty(s1)) return s2;
            else return s1 + delim + s2;
        }
        public static string ContactWithDelim(string str1, string delim, string str2)
        {
            if (string.IsNullOrEmpty(str1)) return str2;
            else if (string.IsNullOrEmpty(str2)) return str1;
            else return str1 + delim + str2;
        }

        /// <summary>
        /// Contact with delim, delim is used after the first not Empty item
        /// </summary>
        /// <param name="items"></param>
        /// <param name="delim"></param>
        /// <returns></returns>
        public static string ContactWithDelimSkipEmpty(IEnumerable<string> items, string delim)
        {
            return ContactWithDelimSkipSome(items, delim, string.Empty);
        }

        /// <summary>
        /// Contact with delim, delim is used after the first not null item
        /// </summary>
        /// <param name="items"></param>
        /// <param name="delim"></param>
        /// <returns></returns>
        public static string ContactWithDelimSkipNull(IEnumerable<string> items, string delim)
        {
            return ContactWithDelimSkipSome(items, delim, null);
        }

        public static string ContactWithDelimSkipSome(IEnumerable<string> items, string delim, string skip)
        {
            StringBuilder text = new StringBuilder();
            bool isFirst = true;
            foreach (string item in items)
            {
                if (item == skip) continue;
                if (isFirst)
                {
                    isFirst = false;
                }
                else
                {
                    text.Append(delim);
                }
                text.Append(item);
            }
            return text.ToString();
        }

        public static string ContactWithDelim(IEnumerable<string> items, string delim)
        {
            return ContactWithDelim(items, delim, null, null);
        }
        public static string ContactWithDelim(IEnumerable<string> items, string delim, string initialValue)
        {
            return ContactWithDelim(items, delim, initialValue, null);
        }
        public static string ContactWithDelim(IEnumerable<string> items, string delim, string initialValue, string endValue)
        {
            StringBuilder text = new StringBuilder(initialValue);
            bool isFirst = true;
            foreach (string item in items)
            {
                if (isFirst)
                {
                    isFirst = false;
                }
                else
                {
                    text.Append(delim);
                }
                text.Append(item);
            }
            text.Append(endValue);
            return text.ToString();
        }

        public static string[] SplitWithSpaces(string text)
        {
            string pattern = "[^ ]+";
            Regex rgx = new Regex(pattern);
            MatchCollection mc = rgx.Matches(text);
            string[] items = new string[mc.Count];
            for (int i = 0; i < items.Length; i++)
            {
                items[i] = mc[i].Value;
            }
            return items;
        }


        public static string ContactWithDelim<T>(IEnumerable<T> items, string delim)
        {
            return ContactWithDelim<T>(items, delim, null, null);
        }

        public static string ContactWithDelim<T>(IEnumerable<T> items, string delim, string initialValue, string endValue)
        {
            StringBuilder text = new StringBuilder();
            text.Append(initialValue);
            bool isFirst = true;
            foreach (T item in items)
            {
                if (isFirst)
                {
                    isFirst = false;
                }
                else
                {
                    text.Append(delim);
                }
                text.Append(item.ToString());
            }
            text.Append(endValue);
            return text.ToString();
        }

        public static string GetHeader(string text, int length)
        {
            if (text.Length <= length)
            {
                return text;
            }
            else
            {
                return text.Substring(0, length);
            }
        }
    }
}