I have 3 files to use spine animation.

.png, .skel, .atlas

And i write code on visual studio 2017 like this

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

namespace WindowsFormsApp1
{
    public partial class Form1 : Form
    {
        private Timer timer;

    private Atlas atlas;
    private SkeletonBinary skBinary;
    private SkeletonData skData;
    private Skeleton sk;
    private Animation ani;

    private AnimationState aniState;
    private AnimationStateData aniStateData;

    public Form1()
    {
        InitializeComponent();

        Size = new Size(800, 480);

        timer = new Timer();
        timer.Interval = 500;
        timer.Tick += new EventHandler(timer_Tick);
        timer.Start();
    }

    private void timer_Tick(object sender, EventArgs e)
    {
        timer.Stop();

        aniState.Update(timer.Interval);
        aniState.Apply(sk);
        sk.UpdateWorldTransform();

        Invalidate();

        timer.Start();
    }

    protected override void OnLoad(EventArgs e)
    {
        try
        {
            base.OnLoad(e);

            atlas = new Atlas("Alchemist.atlas", new MyTextureLoader());
            skBinary = new SkeletonBinary(atlas);
            skData = skBinary.ReadSkeletonData("Alchemist.skel");
            sk = new Skeleton(skData);
            ani = skData.FindAnimation("walk");

            aniStateData = new AnimationStateData(skData);
            aniState = new AnimationState(aniStateData);
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.ToString());
        }
    }

    private void DrawSkin(Graphics g)
    {
        foreach (Slot slot in sk.Slots)
        {
            if (slot.Attachment == null || slot.Attachment.GetType() != typeof(RegionAttachment))
                continue;

            RegionAttachment attach = (RegionAttachment)slot.Attachment;
            AtlasRegion region = (AtlasRegion)attach.RendererObject;

            g.ResetTransform();
            g.TranslateTransform(400, 100);

            g.TranslateTransform(attach.X, attach.Y);
            g.RotateTransform(attach.Rotation);

            g.TranslateTransform(slot.Bone.WorldX, -slot.Bone.WorldY);
            g.RotateTransform(slot.Bone.Rotation);
            g.ScaleTransform(slot.Bone.ScaleX, slot.Bone.ScaleY);

            Rectangle dstRC = new Rectangle(0, 0, region.width, region.height);
            Rectangle srcRC = new Rectangle(region.x, region.y, region.width, region.height);
            g.DrawImage((Image)region.page.rendererObject, dstRC, srcRC, GraphicsUnit.Pixel);

            g.ResetTransform();
        }
    }

    private void DrawBones(Graphics g)
    {
        g.ResetTransform();
        g.TranslateTransform(400, 100);

        Color Color = Color.FromArgb(255, 0, 0, 255);
        foreach (Bone bone in sk.Bones)
        {
            float x = bone.Data.Length + bone.WorldX;
            float y = bone.Data.Length + bone.WorldY;
            g.DrawLine(Pens.Red, new PointF(bone.WorldX, bone.WorldY), new PointF(x, y));
        }

        foreach (Bone bone in sk.Bones)
        {
            g.DrawEllipse(Pens.Blue, bone.WorldX - 2, bone.WorldY - 2, 4, 4);
        }

        g.ResetTransform();
    }

    protected override void OnPaint(PaintEventArgs e)
    {
        base.OnPaint(e);

        Graphics g = e.Graphics;

        DrawSkin(g);
        DrawBones(g);
    }

    public class MyTextureLoader : TextureLoader
    {

        public void Load(AtlasPage page, string path)
        {
            Bitmap img = new Bitmap(path);
            page.width = img.Width;
            page.height = img.Height;
            page.rendererObject = img;
        }

        public void Unload(object texture)
        {
            ((Bitmap)texture).Dispose();
        }
    }
}
}

And i run this program, i can't see any animation and picture.

please help me...