Draw Canvas line problem

Question

Hi folks,

I have a created a Canvas line. here is my source code:

 

using System;

namespace DemoCanvas
{
    public class Canvas
    {
        //char[][] canvasArray;
        char[,] canvasArray;
        int w, h;
        public Canvas(int w, int h)
        {
            h += 2;
            w += 2;
            this.w = w;
            this.h = h;
            canvasArray = new char[h,w];
            drawLine(0, 0, this.w - 1, 0, '-');
            drawLine(0, this.h - 1, this.w - 1, this.h - 1, '-');
            drawLine(0, 1, 0, this.h - 2, '|');
            drawLine(this.w - 1, 1, this.w - 1, this.h - 2, '|');
        }

        public void bucketFill(int x, int y, char mchar)
        {
            if ((int)canvasArray[y, x] != 0)
            {
                return;
            }

            if (x > 0 || x < this.h || y > 0 || y < this.w)
            {
                if ((int)canvasArray[y, x] == 0)
                    canvasArray[y, x] = mchar;
                bucketFill(x + 1, y, mchar);
                bucketFill(x - 1, y, mchar);
                bucketFill(x, y - 1, mchar);
                bucketFill(x, y + 1, mchar);
            }
        }
        public void drawLine(int x1, int y1, int x2, int y2, char mchar)
        {
            for (int i = y1; i <= y2; i++)
            {
                for (int j = x1; j <= x2; j++)
                {
                    canvasArray[i, j] = mchar;
                }
            }
        }

        public void drawRectangle(int x1, int y1, int x2, int y2, char mchar)
        {
            drawLine(x1, y1, x2, y1, mchar);
            drawLine(x1, y1, x1, y2, mchar);
            drawLine(x2, y1, x2, y2, mchar);
            drawLine(x1, y2, x2, y2, mchar);
        }

        public void render()
        {
            for (int i = 0; i < this.h; i++)
            {
                for (int j = 0; j < this.w; j++)
                {
                    Console.WriteLine(canvasArray[i, j]);
                }
                //Console.WriteLine();
            }
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            string command = "";
            while (command != "Q")
            {
                Console.WriteLine("Enter Your Command:(E.g C 4 2) ");
                command = Console.ReadLine();
                draw(command);
            }
            Console.WriteLine("Program Exited!");
        }

        static Canvas canvas;
        private static void draw(String command)
        {
            char ch = command[0];
            String[] cmd;

            switch (ch)
            {
                case 'C':
                    cmd = command.Split(' ');
                    canvas = new Canvas(int.Parse(cmd[1]), int.Parse(cmd[2]));
                    canvas.render();
                    break;
                case 'L':
                    cmd = command.Split(' ');
                    if (canvas == null)
                    {
                        Console.Error.WriteLine("Please draw a canvas first");
                        return;
                    }
                    canvas.drawLine(int.Parse(cmd[1]), int.Parse(cmd[2]), int.Parse(cmd[3]), int.Parse(cmd[4]), 'X');
                    canvas.render();
                    break;
                case 'R':
                    cmd = command.Split(' ');
                    if (canvas == null)
                    {
                        Console.Error.WriteLine("Please draw a canvas first");
                        return;
                    }
                    canvas.drawRectangle(int.Parse(cmd[1]), int.Parse(cmd[2]), int.Parse(cmd[3]), int.Parse(cmd[4]), 'X');
                    canvas.render();
                    break;
                case 'B':
                    cmd = command.Split(' ');
                    if (canvas == null)
                    {
                        Console.Error.WriteLine("Please draw a canvas first");
                        return;
                    }
                    canvas.bucketFill(int.Parse(cmd[1]), int.Parse(cmd[2]), cmd[3][0]);
                    canvas.render();
                    break;
            }
        }
    }
}

Please copy/paste and run it.

Where 4 is for Width and 2 is for height

I want to display output:
 _ _
|     |
|     |
|     |
|_ _ |

I am waiting for your response.
Thanks in Advance