I need to replace a line with particular string with contents of another file using c#

Question

I have two files , File1.txt and File2.txt , I need to replace a particular string in file1 with contents of file2 using C# console application.

file 1 :

This is a sample file

..

code-block ..

some text

end of file

File 2 :

// some c# code //

i need to replace the string "code-block" with the contents of File 2.

Edit 1:

I had tried to read the file as Array and also as a list

var fileContent = File.ReadAllLines(file_path);
            List<string> allLinesText = File.ReadAllLines(file_path).ToList();
            string parentdirectory = Directory.GetParent(Path.GetDirectoryName(file_path)).FullName.ToString(); 

            foreach( var line in fileContent)
            {

                if ( line.Contains("{% code-block %}"))
                {
                    string code_path = line.Replace("{%", string.Empty).Replace("%}", string.Empty).Trim();
                    string code_fullpath = Path.Combine(parentdirectory, code_path);
                    if(File.Exists(code_fullpath))
                    {
                        var code_content = File.ReadAllLines(code_fullpath);
                       // int insert_code_at = 

                     // allLinesText.Insert( allLinesText.IndexOf(line)
                    }
                    
                }

Answer 1

You can use String.Replace. Sample code:

string text = File.ReadAllText("file1.txt");
text = text.Replace("text needs to be replaced", "new text");
File.WriteAllText("file1.txt", text);