Question

How do i dynamically removing/adding(cancel the removal) form area using region and graphics path class

Answer 1

To change the shape of your Form dynamically, just set the Region property of the form to a new Region object created from a GraphicsPath. For example, a form with a single button on it could change it’s shape like this: (working example)

using System;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Windows.Forms;

namespace Sample
{
    public class ShapedForm : Form
    {
        Button testbutton;

        public ShapedForm()
        {
            // Create a button.
            testbutton = new Button();
            testbutton.Location = new Point(10, 10);
            testbutton.Size = new Size(50, 50);
            testbutton.Text = "Click me!";
            testbutton.Click += new EventHandler(this.testbutton_Click);
            this.Controls.Add(testbutton);

            // Remove the border around the form.
            this.FormBorderStyle = FormBorderStyle.None;

            // Set the initial shape of the form to an ellipse.
            GraphicsPath path = new GraphicsPath();
            path.AddEllipse(0, 0, 200, 100);

            this.Region = new Region(path);
        }

        private void testbutton_Click(object sender, EventArgs e)
        {
            // Change the shape of the form to some other ellipse.
            GraphicsPath path = new GraphicsPath();
            path.AddEllipse(0, 0, 100, 100);
            path.AddEllipse(120, 40, 50, 50);

            this.Region = new Region(path);
        }
    }
}