How can I create button with solid border(3d), like picture below on C# winforms?

Panel <
If you don't care about how thick the border is, you can use the following code. (I choose my checkbox' appearance as button, and I like it raised when not checked and sunken when checked)
private void checkbox_paint(object sender, PaintEventArgs e)
{
CheckBox myCheckbox = (CheckBox)sender;
Rectangle borderRectangle = myCheckbox.ClientRectangle;
if (myCheckbox.Checked)
{
ControlPaint.DrawBorder3D(e.Graphics, borderRectangle,
Border3DStyle.Sunken);
}
else
{
ControlPaint.DrawBorder3D(e.Graphics, borderRectangle,
Border3DStyle.Raised);
}
}
Just in case you don't know how to use this code: All you need to do is choose your button/checkbox in your designer, then go to the Properties window and choose the Events tab (click the Thunderbolt). Find the event called Paint and type your event handler's name without the parenthesis in box next to it (such as checkbox_paint). In the code window that pops up afterwards fill in your code. Then you are all set.