public class TreeNode
    {
        public int Data { get; set; }
        public TreeNode Left { get; set; }
        public TreeNode Right { get; set; }
    }

In-Order

public void Inorder(TreeNode node)
        {
            if (node == null)
            {
                return;
            }
            Inorder(node.Left);
            Console.Write(node.Data + " >");
            Inorder(node.Right);
        }

Pre-Order

public void Preorder(TreeNode node)
        {
            if (node == null)
            {
                return;
            }
            Console.Write(node.Data + " >");
            Preorder(node.Left);
            Preorder(node.Right);
        }

Post-Order

public void Postorder(TreeNode node)
   {
       if (node == null)
       {
           return;
       }

       Postorder(node.Left);
       Postorder(node.Right);
       Console.Write(node.Data + " >");
   }