Ignore case strings

when enter the text to find the string i want to ignore the case how to implement that in a context below

Code:

 public override void Search()
        {
            
            //file = new FileStream(@"C:\username.txt", FileMode.Open, FileAccess.Read);
            
            Console.WriteLine("Input a string ");
            String data = Console.ReadLine();
            sr = File.OpenText(@"C:\username.txt");
            String st = sr.ReadToEnd();
           // How to implement ignore cases 
            
                if (st.Contains(data))
                {
                    Console.WriteLine("Found at position :" + st.IndexOf(data));
                }
                else
                {
                    Console.WriteLine("Not Found");
                }

Thanks,

 

How to put CompareNoCase in this method?

 

Any help?

 

Thanks Shabbir for this but i got one solution on my own but now as Search functionality works i have something same in switch cases

Code:

String s;
                s = Console.ReadLine();
                
                
                switch (s)
                {
                    case "g":
                        Console.Clear();
                        uname.getUserName();
                        return choices();
                       // break;

if i want to enter "G" it doesnt accept how to do that?

 

Thanks a million, Shabbir. It worked for me. Now i will continue on how to delete a line from the text file. I will do separate thread at some stage.