Анимация загрузки

using System;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Linq;
using System.Windows.Forms;
public class SpinningCircles : Control
{
    int increment = 1;
    int radius = 4;
    int n = 8;
    int next = 0;
    Timer timer;
    public SpinningCircles()
    {
        timer = new Timer();
        this.Size = new Size(100, 100);
        timer.Tick += (s, e) => this.Invalidate();
        if (!DesignMode)
            timer.Enabled = true;
        SetStyle(ControlStyles.AllPaintingInWmPaint |
                 ControlStyles.OptimizedDoubleBuffer |
                 ControlStyles.ResizeRedraw | ControlStyles.UserPaint |
                 ControlStyles.SupportsTransparentBackColor, true);
        BackColor = Color.Transparent;
    }
    protected override void OnPaint(PaintEventArgs e)
    {
        if (Parent != null && this.BackColor == Color.Transparent)
        {
            using (var bmp = new Bitmap(Parent.Width, Parent.Height))
            {
                Parent.Controls.Cast<Control>()
                      .Where(c => Parent.Controls.GetChildIndex(c) > Parent.Controls.GetChildIndex(this))
                      .Where(c => c.Bounds.IntersectsWith(this.Bounds))
                      .OrderByDescending(c => Parent.Controls.GetChildIndex(c))
                      .ToList()
                      .ForEach(c => c.DrawToBitmap(bmp, c.Bounds));
 
                e.Graphics.DrawImage(bmp, -Left, -Top);
            }
        }
        e.Graphics.SmoothingMode = SmoothingMode.HighQuality;
        int length = Math.Min(Width, Height);
        PointF center = new PointF(length / 2, length / 2);
        int bigRadius = length / 2 - radius - (n - 1) * increment;
        float unitAngle = 360 / n;
        if (!DesignMode)
            next++;
        next = next >= n ? 0 : next;
        int a = 0;
        for (int i = next; i < next + n; i++)
        {
            int factor = i % n;
            float c1X = center.X + (float)(bigRadius * Math.Cos(unitAngle * factor * Math.PI / 180));
            float c1Y = center.Y + (float)(bigRadius * Math.Sin(unitAngle * factor * Math.PI / 180));
            int currRad = radius + a * increment;
            PointF c1 = new PointF(c1X - currRad, c1Y - currRad);
            e.Graphics.FillEllipse(Brushes.Black, c1.X, c1.Y, 2 * currRad, 2 * currRad);
            using (Pen pen = new Pen(Color.White, 2))
                e.Graphics.DrawEllipse(pen, c1.X, c1.Y, 2 * currRad, 2 * currRad);
            a++;
        }
    }
    protected override void OnVisibleChanged(EventArgs e)
    {
        timer.Enabled = Visible;
        base.OnVisibleChanged(e);
    }
}
Sample 2 Code - TransparentPictureBox Code
 
using System;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Linq;
using System.Windows.Forms;
class TransparentPictureBox : PictureBox
{
    public TransparentPictureBox()
    {
        this.BackColor = Color.Transparent;
    }
    protected override void OnPaint(PaintEventArgs e)
    {
        if (Parent != null && this.BackColor == Color.Transparent)
        {
            using (var bmp = new Bitmap(Parent.Width, Parent.Height))
            {
                Parent.Controls.Cast<Control>()
                      .Where(c => Parent.Controls.GetChildIndex(c) > Parent.Controls.GetChildIndex(this))
                      .Where(c => c.Bounds.IntersectsWith(this.Bounds))
                      .OrderByDescending(c => Parent.Controls.GetChildIndex(c))
                      .ToList()
                      .ForEach(c => c.DrawToBitmap(bmp, c.Bounds));
 
                e.Graphics.DrawImage(bmp, -Left, -Top);
            }
        }
        base.OnPaint(e);
    }
}