Rounding four corners of the TextBox

Hi!
I know I'm a bit late, but for anyone who still needs it check -> this vid

Create your own class that inherits from Textbox and apply the code... something like this ->

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

class round :TextBox
    {
        [System.Runtime.InteropServices.DllImport("gdi32.dll", EntryPoint = "CreateRoundRectRgn")]
        private static extern IntPtr CreateRoundRectRgn
        (
            int nLeftRect, // X-coordinate of upper-left corner or padding at start
            int nTopRect,// Y-coordinate of upper-left corner or padding at the top of the textbox
            int nRightRect, // X-coordinate of lower-right corner or Width of the object
            int nBottomRect,// Y-coordinate of lower-right corner or Height of the object
            //RADIUS, how round do you want it to be?
            int nheightRect, //height of ellipse 
            int nweightRect //width of ellipse
        );
        protected override void OnCreateControl()
        {
            base.OnCreateControl(); 
             this.Region = System.Drawing.Region.FromHrgn(CreateRoundRectRgn(2,3,this.Width,this.Height,15,15)); //play with these values till you are happy
}

That's it!
;)

Override paint event of button and draw it yourself, you can use an image too.