Animator Example

AnimationState.cs

using System;
using System.Collections.Generic;
using System.Linq;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Audio;

namespace MyMonoGame
{
    public class AnimationState
    {
        public string Name;
        public int Start;
        public int End;
        public bool Loop = true;
        public float Speed = 10;
        public List<AnimationEvent> Events;
        public bool Reverse;

        public AnimationState(string name, int start, int? end = null, bool loop = true, float speed = 10, List<AnimationEvent> events = null)
        {
            Name = name;
            Start = start;
            End = end ?? start;
            Loop = loop;
            Speed = speed;
            Events = events;
            if (end < start)
            {
                Reverse = true;
            }
        }
    }
}

Animator.cs

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace MyMonoGame
{
    public class Animator : Component
    {
        // Public 

        public AnimationState State;
        public int Offset = 0;
        public float Frame = 1;

        // Private

        Sprite sprite;
        int min = 1;
        int max;
        float speed = 10;

        AnimationState oldState;
        int? oldFrame;

        // Methods

        public void SetState(AnimationState state)
        {
			sprite = sprite ?? Entity.GetComponent<Sprite>();

            
            if (state?.Name != oldState?.Name)
            {
                Frame = state.Start;
                int flooredFrame = (int)Math.Floor(Frame);
                sprite.TileNumber = flooredFrame + Offset;
            }

            speed = state.Speed;
			State = state;
        }

        public override void Setup()
        {
            base.Setup();

            sprite = Entity.GetComponent<Sprite>();

            // Calculate maximum Frame based on our Sprite's spritesheet
            max = (int)MathF.Floor(
                (sprite.Texture.Width / sprite.TileSize.Value)
                * (sprite.Texture.Height / sprite.TileSize.Value)
            );
        }

        public override void Start()
        {
            base.Start();
        }

        public override void Update()
        {
            base.Update();

            if (State == null) return;

            // Check if State is different
            if (State?.Name != oldState?.Name)
            {
                Frame = State.Start;
            }

            speed = State.Speed;

            // Increment Frame
            Frame += (speed * Time.Delta) * (State.Reverse ? -1 : 1);

            // Check if we've passed the end of the spritesheet.
            if (Frame >= max + min) Frame = State.Loop ? State.Start : max;

            // Loop
            if (State.Reverse)
            {
                if (Frame <= State.End) Frame = State.Loop ? State.Start : State.End;
            }
            else
            {
                if (Frame >= State.End + 1) Frame = State.Loop ? State.Start : State.End;
            }

            // Update our Sprite component
            int flooredFrame = (int)Math.Floor(Frame);
            sprite.TileNumber = flooredFrame + Offset;

            // Process events
            if (flooredFrame != oldFrame && State.Events != null && State.Events.Count > 0)
            {
                AnimationEvent animationEvent = State.Events.Find(e => e.Frames.Contains(flooredFrame));
                if (animationEvent != null)
                {
                    animationEvent.Action();
                }
            }

            // Remember stuff
            oldFrame = flooredFrame;
            oldState = State;
        }
    }
}