resizing arrays

[jonnydexter]

im looking for a way to resize an array e.g. from myarray[10,10] to myarray[20,20] while preserving the contents , by all accounts the best way is to use the array.copy. i found a snippet of code on a answer elsewhere which says :-

public static void ResizeArray<T>(ref T[,] original, int cols, int rows)
        {
            T[,] newArray = new T[rows, cols];
            //copy the contents of the old array to the new one
            Array.Copy(original, newArray, original.Length);
            //set the original to the new array
            original = newArray;
        }

how do i pass my array into it ?

Resize_array<int>( [,] myarray , new rows, newcols)
??

i can see how the swap works but what happens to the old array, does garbage collection dispose of it or should i be handling that.

Does anyone have a better more efficient way ?

tia