How to make a button that don't be RECTANGULAR and be s.t like circle

0) Winforms - You have to create a custom control that at least overrides the Paint event.

1) WPF or Silverlight - you have to come up with your own style/data template and draw the desired shape. (You could also just create an image and use that in your custom style.

2) ASP.Net - just come up with a button image with the desired shape, and use that as the button on your web page.

In the end, Google is your friend.

A few days ago,I wrote one. Here,I will give you.

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Drawing.Drawing2D ;

namespace myTrackBar
{
    public partial class button : Button
    {
        private Color color1 =Color.White  ;
        private Color color2 = Color.FromArgb(81, 198, 255);
        public button()
        {
            InitializeComponent();
            this.SetStyle(ControlStyles.UserPaint, true);//自动重绘
        }
        /// <summary>
        /// 画圆形按钮
        /// </summary>
        /// <param name="pe"></param>
        protected override void OnPaint(PaintEventArgs pe)
        {
            base.OnPaint(pe);
            pe.Graphics.SmoothingMode = SmoothingMode.AntiAlias;//使边框平滑
            GraphicsPath path = new GraphicsPath();
            path.AddEllipse (this.ClientRectangle);//画椭圆
            PathGradientBrush pbr = new PathGradientBrush(path);
            pbr.CenterColor = color1;
            Color[] colors = { color2  };
            pbr.SurroundColors = colors;
            pe.Graphics.FillPath(pbr, path);//填充椭圆
            DrawText(pe);//椭圆上写字
            this.Region = new Region(path);

        }
        /// <summary>
        /// 在按钮上写字
        /// </summary>
        /// <param name="e"></param>
        private void DrawText(PaintEventArgs e)
        {
            float x = this.Width  / 2-4;
            float y = this.Height / 2-4;
            e.Graphics.DrawString(this.Text , this.Font, new SolidBrush(Color.Red),x,y);//指定位置写字
        }
        /// <summary>
        /// 鼠标指定后改变颜色
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button_MouseEnter(object sender, EventArgs e)
        {
            color2 = Color.Pink;
        }
        /// <summary>
        /// 鼠标离开颜色复原
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button_MouseLeave(object sender, EventArgs e)
        {
            color2 = Color.FromArgb(81, 198, 255);

        }
    }
}