Question

The code below create one circle inside the windows form.
This code compiled without any errors. But it didn’t draw the ellipse?! Why?

using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows.Forms;
using System.Drawing;

namespace WindowsFormsApplication1
{
    public class Task1 : Form1
    {
        public void FillEllipseInt(PaintEventArgs e)
        {
            SolidBrush redBrush = new SolidBrush(Color.Red);
            int x = 100;
            int y = 100;
            int width = 200;
            int height = 100;
            e.Graphics.FillEllipse(redBrush, x, y, width, height);
        }

        static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            Application.Run(new Form1());
        }
    }
}

Answer 1

You need to attach the Paint event of the form and from that call your FillEllipseInt method. Also, you need to change Application.Run(new Form1()); to Application.Run(new Task1()); as (at least in the code you’ve shown) there’s not Form1 class. This is also why I think that Task1 should inherit from Form and not Form1.