System Drawing Drawing2d C# by API

using System;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
public class Form1 : System.Windows.Forms.Form{
    private System.ComponentModel.IContainer components;
  public Form1(){
    InitializeComponent();
  }
  #region Windows Form Designer generated code
  private void InitializeComponent(){
      this.components = new System.ComponentModel.Container();
      this.timer1 = new System.Windows.Forms.Timer(this.components);
      this.timer1.Enabled = true;
      this.timer1.Tick += new System.EventHandler(this.timer1_Tick);
      this.AutoScaleBaseSize = new System.Drawing.Size(6, 15);
      this.ClientSize = new System.Drawing.Size(292, 260);
      this.Name = "Form1";
      this.Text = "LinearGradientBrush Demo";
      this.Load += new System.EventHandler(this.Form1_Load);
      this.Paint += new System.Windows.Forms.PaintEventHandler(this.Form1_Paint);
    }
  #endregion
  static void Main(){
    Application.Run(new Form1());
  }
    private void Form1_Load(object sender, System.EventArgs e) {
      this.BackColor = Color.FromArgb(255, 0, 0, 255);  
    }
    private System.Windows.Forms.Timer timer1;
    private float angle = 0;
    private LinearGradientBrush GetBrush()
    {
      return new LinearGradientBrush(
        new Rectangle( 20, 20, 200, 100),
        Color.Orange,
        Color.Yellow,
        0.0F,
        true);
    }
    private void Rotate( Graphics graphics, LinearGradientBrush brush )
    {
      brush.RotateTransform(angle);
      brush.SetBlendTriangularShape(.5F);
      graphics.FillRectangle(brush, brush.Rectangle);
    }
    private void Rotate(Graphics graphics)
    {
      angle += 5 % 360;
      Rotate(graphics, GetBrush());
    }
    private void timer1_Tick(object sender, System.EventArgs e)
    {
      Rotate(CreateGraphics());
    }
    private void Form1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
    {
      Rotate(e.Graphics);
    }
}