C#函数库

//读取文本文件并返回内容不同的那一行
        public static String different(String sOldFile, String sNewFile)
        {
            StreamReader srOld = new StreamReader(sOldFile);
            StreamReader srNew = new StreamReader(sNewFile);
            String sOldLine;
            String sNewLine;
            while(true)
            {
                sOldLine = srOld.ReadLine();
                sNewLine = srNew.ReadLine();
                if( (sOldLine==null) || (sNewLine==null))
                {
                    return null;
                }
                if( sOldLine == sNewLine)
                {
                    continue;
                    
                }
                else
                {
                    return sNewLine;
                }
                
            }
        }