Loops - Spiral Matrix

using System;

class MatrixSpiral
{
    static void Main(string[] args)
    {
        int size = 0;
        bool successParse;
        do
        {
            Console.Write("Enter the rows/cols of the matrix: ");
            successParse = int.TryParse(Console.ReadLine(), out size);
        } while (!successParse);

        int[,] matrix = new int[size, size];
        int count = 1;
        int startRow = 0;
        int startCol = 0;
        int endRow = size - 1;
        int endCol = size - 1;

        do
        {
            //move right
            for (int cols = startCol; cols <= endCol; cols++)
            {
                matrix[startRow, cols] = count;
                count++;
            }

            startRow = startRow + 1;


            //move down
            for (int i = startRow; i <= endRow; i++)
            {
                matrix[i, endCol] = count;
                count++;
            }

            endCol = endCol - 1;


            //move left
            for (int i = endCol; i >= startCol; i--)
            {
                matrix[endRow, i] = count;
                count++;
            }

            endRow = endRow - 1;
            //move up
            for (int i = endRow; i >= startRow; i--)
            {
                matrix[i, startCol] = count;
                count++;
            }

            startCol = startCol + 1;
        } while (size * size >= count);

        //print matrix
        for (int i = 0; i < size; i++)
        {
            for (int j = 0; j < size; j++)
            {
                Console.Write("{0,4}", matrix[i, j]);
            }

            Console.WriteLine();
        }
    }
}