C# .NET - how to set array range dynamically in windows form application

While we entering the data in textboxes dynamically like[s,a,c,h],How to set range for these in windows application forms c#.

huh?

//1st declare array with 0 size
 string[] array = new string[0];

//While adding data increase size of array
Array.Resize(ref  array, array.Length+1);
 array[array.Length - 1] ='a';