Replace strings between specified tags

[bullet_1]

In the following code, the pattern is reading text between specified tags and I want to replace text in between those specified tags. I tried but replacing in whole file.

string input = File.ReadAllText(@"D:\text\div.txt");
            string pattern = @"<body.*?>(.|\n)*?</body>";//reads text between specified tags
            MatchCollection matches = Regex.Matches(input, pattern);
            // Console.WriteLine("Matches found: {0}", matches.Count);
            input = input.Replace("oldvalue", "newvalue");
            File.WriteAllText(@"D:\text\div.txt", input);
            if (matches.Count > 0)
                foreach (Match m in matches)
                Console.WriteLine(m.Groups[0]);
                Console.ReadLine();

plz help me
thanks in advance

[castajiz_2]

do you really have to use regex for this?

[castajiz_2]

i really don t know where all the people have gone so i must do something
here you go try this, it s not using regex, actually linq with lamda is powerfull with this but this is a simple solution to it

 static void Main(string[] args)
        {
            string html_tag = "";
            int position1 = 0;
            int position2 = 0;
            string insert = "";
            string text_to_put="Have a nice day";// whatever you want to replace the first string with

            string document_path=@"D:\text\div.txt";
            string input = "";
            string concatenate="";
            string pattern = @"<body.*?>(.|\n)*?</body>";//regex code, but not needed


            using (StreamReader str=new StreamReader(document_path))
            {

                while (!str.EndOfStream) 
                {
                    input = str.ReadLine();
                    concatenate=concatenate+input; //instead of regex
                    position1 = input.IndexOf('<');
                    position2 = input.IndexOf('>');


                    if (input.Contains("body")) 
                    {
                        for (int i = position1; i<=position2 ; i++)
                        {
                             html_tag = html_tag + input[i];
                        }
                    }
                    str.Close();
              }

            }
            concatenate=concatenate.Replace(concatenate,text_to_put);

            insert = html_tag.Insert(html_tag.IndexOf('>')+1,concatenate);

            Console.WriteLine(insert);

                  using (StreamWriter sw = new StreamWriter(document_path)) 
                  {
                      sw.Write(insert);
                      sw.Close();
                  }
            Console.ReadLine();

            //// we don t need this at the moment 
            //if (matches.Count > 0)
            //    foreach (Match m in matches)
            //        Console.WriteLine(m.Groups[0]);
            //Console.ReadLine();
        }

[bullet_1]

while (!str.EndOfStream)//getting error cannot read from a closed textreader

[castajiz_2]

 static void Main(string[] args)
        {
            string html_tag = "";
            int position1 = 0;
            int position2 = 0;
            string insert = "";
            string text_to_put="Have a nice day";// whatever you want to replace the first string with
            string document_path=@"D:\text\div.txt";
            string input = "";
            string concatenate="";
            string pattern = @"<body.*?>(.|\n)*?</body>";//regex code, but not needed
            using (StreamReader str=new StreamReader(document_path))
            {
                while (!str.EndOfStream) 
                {
                    input = str.ReadLine();
                    concatenate=concatenate+input; //instead of regex
                    position1 = input.IndexOf('<');
                    position2 = input.IndexOf('>');
                    if (input.Contains("body")) 
                    {
                        for (int i = position1; i<=position2 ; i++)
                        {
                             html_tag = html_tag + input[i];
                        }
                    }

                 }
              str.Close();
            }
            concatenate=concatenate.Replace(concatenate,text_to_put);
            insert = html_tag.Insert(html_tag.IndexOf('>')+1,concatenate);
            Console.WriteLine(insert);
                  using (StreamWriter sw = new StreamWriter(document_path)) 
                  {
                      sw.Write(insert);
                      sw.Close();
                  }
            Console.ReadLine();
            //// we don t need this at the moment 
            //if (matches.Count > 0)
            //    foreach (Match m in matches)
            //        Console.WriteLine(m.Groups[0]);
            //Console.ReadLine();
        }

i m sorry, but you could have seen that i put the .close() inside the while loop which gives an error, just put it outside the while loop

[castajiz_2]

The previous code will work but everything will be in the same line. If that bothers you then use this but still if retrieving a html i think that it shouldn t be problem but neverthless.

static void Main(string[] args)
        {
            string html_tag="";
            int position1 = 0;
            int position2 = 0;
            string insert = "";
            string text_to_put="Have a nice day";// whatever you want to replace the first string with

            string document_path=@"D:\text\div.txt";
            string input = "";
            string concatenate="";
            string pattern = @"<body.*?>(.|\n)*?</body>";//regex code, but not needed


            using (StreamReader str=new StreamReader(document_path))
            {

                while (!str.EndOfStream) 
                {
                    input = str.ReadLine();
                    concatenate=concatenate+input; //instead of regex
                    position1 = input.IndexOf('<');
                    position2 = input.IndexOf('>');


                    if (input.Contains("body")) 
                    {
                        for (int i = position1; i<=position2 ; i++)
                        {
                             html_tag = html_tag + input[i];
                        }
                        html_tag = html_tag + " ";
                    }

              }
                str.Close();

            }

            string [] array=new string[2];
            array = html_tag.Split(' ');
           concatenate=concatenate.Replace(concatenate,text_to_put);


            Console.WriteLine(insert);

                  using (StreamWriter sw = new StreamWriter(document_path)) 
                  {
                      sw.WriteLine(array[0]);
                      sw.WriteLine(concatenate);
                      sw.Write(array[1]);
                      sw.Close();
                  }
            Console.ReadLine();

            //// we don t need this at the moment 
            //if (matches.Count > 0)
            //    foreach (Match m in matches)
            //        Console.WriteLine(m.Groups[0]);
            //Console.ReadLine();
        }