== Developing Custom Controls in .NET ==

== Create RoundButton ==
Source: //Creating Custom .NET Controls in C#//, [[http://www.ondotnet.com/pub/a/dotnet/2002/03/18/customcontrols.html]]

 * Create DLL project (.NET 2.0)
 * Add necessary References.  Under Solutions Explorer, select References > Add Reference > .NET (tab), and select ''System.Windows.Forms'' and ''System.Drawing''.
 * Add ''OnPaint()'' code to new custom control:<code csharp>
using System.Windows.Forms;
using System.Drawing;

namespace MyCustomControls {

  public class RoundButton : UserControl {

    public Color backgroundColor = Color.Blue;

    protected override void OnPaint(PaintEventArgs e) 
    {
      Graphics graphics = e.Graphics;
      int penWidth = 4;
      Pen pen = new Pen(Color.Black, 4);

      int fontHeight = 10;
      Font font = new Font("Arial", fontHeight);

      SolidBrush brush = new SolidBrush(backgroundColor);
      graphics.FillEllipse(brush, 0, 0, Width, Height);
      SolidBrush textBrush = new SolidBrush(Color.Black);

      graphics.DrawEllipse(pen, (int) penWidth/2, 
        (int) penWidth/2, Width - penWidth, Height - penWidth);

      graphics.DrawString(Text, font, textBrush, penWidth, 
        Height / 2 - fontHeight);

    }
  }
}
</code>
 * Compile DLL.
 * Open Windows Form project.
 * Add custom controls to ToolBox palette.  Right-click on ToolBox, then Choose Items > .NET Framework Components > Browse (button).  Select the custom control DLL created above.
 * Go to ToolBox and select the control and place it on a form in the project.