how to create irregular shape button?

[AceInfinity]

here is somethings you may need, an image shaped button:
http://www.youtube.com/watch?v=K_JzL4kzCoE

This is an old thread, but that's not a good way of doing it. What Hannes posted was GDI, and although all you really need is the OnPaint() event method, you may want others to give it a bit more 'animation'.

Here's a button I created a while ago for an example to show someone else:

//-------------------------------
// Design Author: AceInfinity
// Name: BlueButton
// Date: December 3, 2012
//-------------------------------
 
using System;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Windows.Forms;
 
namespace CustomControls
{
	class BlueButton : Button
	{
		MOUSESTATE MState;
		Rectangle ButtonRect;
 
		enum MOUSESTATE
		{
			Down, Up, Hover, Leave
		}
 
		#region Constructor
		public BlueButton()
		{
			this.DoubleBuffered = true;
			this.Size = new Size(80, 25);
 
			//Set initial size for Graphics to use
			ButtonRect = Rectangle.FromLTRB(0, 0,
				this.ClientRectangle.Right - 1, this.ClientRectangle.Bottom - 1);
			MState = MOUSESTATE.Leave;
		}
		#endregion
 
		#region Overrides
		protected override void OnPaint(PaintEventArgs pevent)
		{
			base.OnPaint(pevent);
 
			//Setup
			Graphics G = pevent.Graphics;
			G.SmoothingMode = SmoothingMode.AntiAlias;
			G.Clear(Color.FromArgb(255, 230, 230, 230));
 
			//Choose brushes and pens
			SolidBrush SB = new SolidBrush(Color.FromArgb(100, 0, 100, 200));
			Pen P = new Pen(SB, 1f);
 
			//Draw the border
			G.DrawRectangle(P, Rectangle.FromLTRB(0, 0, ClientRectangle.Right - 1, ClientRectangle.Bottom - 1));
 
			Color TopGradient;
			Color BottomGradient;
 
			TopGradient = BottomGradient = Color.Black;
 
			switch (MState)
			{
				case MOUSESTATE.Down:
					TopGradient = Color.FromArgb(100, 0, 180, 255);
					BottomGradient = Color.FromArgb(100, 0, 180, 255);
					break;
				case MOUSESTATE.Hover:
					TopGradient = Color.FromArgb(10, 0, 210, 255);
					BottomGradient = Color.FromArgb(100, 0, 210, 255);
					break;
				case MOUSESTATE.Leave:
					TopGradient = Color.FromArgb(10, 0, 180, 255);
					BottomGradient = Color.FromArgb(100, 0, 180, 255);
					break;
			}
 
			//Fill the rectangle with a linear gradient
			using (LinearGradientBrush LGB = new LinearGradientBrush(ButtonRect,
				TopGradient, BottomGradient, 90f))
			{
				G.FillRectangle(LGB, ButtonRect);
			}
 
			//Draw the text to the button
			GDrawString(G, this.Text);
 
			P.Dispose();
			SB.Dispose();
		}
 
		protected override void OnMouseDown(MouseEventArgs mevent)
		{
			base.OnMouseDown(mevent);
			MState = MOUSESTATE.Down;
			this.Invalidate();
		}
 
		protected override void OnMouseUp(MouseEventArgs mevent)
		{
			base.OnMouseUp(mevent);
			MState = MOUSESTATE.Hover;
			this.Invalidate();
		}
 
		protected override void OnMouseEnter(EventArgs e)
		{
			base.OnMouseEnter(e);
			MState = MOUSESTATE.Hover;
			this.Invalidate();
		}
 
		protected override void OnMouseLeave(EventArgs e)
		{
			base.OnMouseLeave(e);
			MState = MOUSESTATE.Leave;
			this.Invalidate();
		}
 
		protected override void OnResize(EventArgs e)
		{
			base.OnResize(e);
			//Set new size for Graphics to use
			ButtonRect = Rectangle.FromLTRB(0, 0,
				this.ClientRectangle.Right - 1, this.ClientRectangle.Bottom - 1);
		   
			//Force the control to be redrawn
			this.Invalidate();
		}
		#endregion
 
		#region Helper Methods
		protected void GDrawString(Graphics G, string text)
		{
			if (text.Length > 0)
			{
				Size size = G.MeasureString(text, Font, Width).ToSize();
				Point pos = new Point(this.Width / 2 - size.Width / 2, this.Height / 2 - size.Height / 2);
				using (SolidBrush SB = new SolidBrush(Color.FromArgb(200, 0, 150, 220)))
				{
					G.DrawString(text, this.Font, SB, pos.X, pos.Y);
				}
			}
		}
		#endregion
	}
}

Although it's a regular rectangle, you can do what you want... Here was a full theme I created: