C#

private void Action(int ust_id) 
{ 
     MySqlCommand cmd = new MySqlCommand("Select * From kategoriler_tablo Where UstKategoriId=" + ust_id.ToString(), c); 
     c.Open(); 
     MySqlDataReader r = cmd.ExecuteReader(); 
     while (r.Read()) { 

          if (ust_id != 0) { 
               treeView1.Nodes.Find(ust_id.ToString(), true)(0).Nodes.Add(r("id").ToString(), r("KategoriAdi").ToString()); 

          } else { 
               treeView1.Nodes.Add(r("id").ToString(), r("KategoriAdi").ToString()); 
          } 
          Action(Convert.ToInt32(r("id"))); 
     } 
     r.Close(); 
     c.Close() 
} 

private void Button1_Click(System.Object sender, System.EventArgs e) 
{ 
    if (c.State != ConnectionState.Open) { 
     } 
     TreeView1.Nodes.Clear(); 
     TreeView1.Update(); 
     c.close(); 
     Action(0); 
}

private static void ApplyBehaviour(IEnumerator items, Behaviour behaviour = null)  
        {
	        while(items.MoveNext())
		        {
			        ItemModel item = (ItemModel)items.Current;
		
			        if(item.type = parent)
			        {
				        parentModel parentModel = (parentModel)item;
				
				        if(parentModel.HasBehaviour)
				        {
					        behaviour = parentModel.Behaviour;
				        }
				
				        ApplyBehaviour(parentModel.Children.GetEnumerator(), behaviour);
	                                 
                                         if(parentModel.HasBehaviour)
				        {
					        behaviour = null;
				        }
			        }			
			
			        item.Behaviour = behaviour;
		        }
	        }
        }

DrawRoi()
{
RectangleF roi = Roi;                               

RectangleF rect = new RectangleF()
{
        X = (float)Frame.Width * roi.X,
        Y = (float)Frame.Height * roi.Y,
        Width = (float)Frame.Width * roi.Width,
        Height = (float)Frame.Height * roi.Height
};

// draw roi if it is smaller than the whole image
if (rect.Left > 0 || rect.Right < (float)FrameWithRoi.Width ||
    rect.Top > 0 || rect.Bottom < (float)FrameWithRoi.Height)
{
        Graphics g = Graphics.FromImage(FrameWithRoi);
        g.DrawImage(Frame, 0, 0);
        using (Bitmap region = new Bitmap(FrameWithRoi.Width, FrameWithRoi.Height, FrameWithRoi.PixelFormat))
        {
                Graphics roi_g = Graphics.FromImage(region);
                roi_g.FillRectangle(new SolidBrush(Color.FromArgb(64, 0, 0, 0)), new Rectangle(0, 0, FrameWithRoi.Width, FrameWithRoi.Height));
                roi_g.FillRectangle(new SolidBrush(Color.Red), rect);
                region.MakeTransparent(Color.Red);
                g.DrawImage(region, 0, 0);
        }
}                

this.framePictureBox.Image = FrameWithRoi;
}