为什么javascript发送元素到我的事件处理程序，当该元素没有事件？(Why is javascript sending an element to my event handler, when that element has no event?)

 我不确定您的PlayingCard类是如何编码的，但您的问题似乎有很大一部分来自其设计。 以这个实现为例： 
 
 PlayingCard类 
 
public class PlayingCard : IComparable<PlayingCard>
{
    private int value;
    private int suit;
    private Bitmap cardImage;

    public int Value => value;
    public string ValueName => ValueToName(value);

    public int Suit => suit;
    public string SuitName => SuitToName(suit);

    public Bitmap CardImage => cardImage;

    public PlayingCard(int value, int suit, Bitmap cardImage)
    {
        this.value = value;
        this.suit = suit;
        this.cardImage = cardImage;
    }

    private string ValueToName(int n)
    {
        switch (n)
        {
            case 0:
                return "Ace";
            case 1:
            case 2:
            case 3:
            case 4:
            case 5:
            case 6:
            case 7:
            case 8:
            case 9:
                return (n+1).ToString();
            case 10:
                return "Jack";
            case 11:
                return "Queen";
            case 12:
                return "King";
            default:
                throw new ArgumentException("Unrecognized card value.");

        }
    }

    private string SuitToName(int s)
    {
        switch (s)
        {
            case 0:
                return "Clubs";
            case 1:
                return "Diamonds";
            case 2:
                return "Spades";
            case 3:
                return "Hearts";
            default:
                throw new ArgumentException("Unrecognized card suit");
        }
    }

    public int CompareTo(PlayingCard other)
    {
        int result = this.Suit.CompareTo(other.Suit);

        if (result != 0)
            return result;

        return this.Value.CompareTo(other.Value);
    }

    public override string ToString()
    {
        return String.Format("{0} of {1}", ValueName, SuitName);
    }
}
 
 它将所有的比较和价值转换编码在其中，因此您不必担心创建高度专业化的方法来进行无关转换。 你可以像这样在一个套牌中使用它： 
 
 数组实现 
 
// How to initialize deck
PlayingCard[] deck = Enumerable.Range(0, 52)
                        .Select(x => new PlayingCard(x % 13, x / 13, imageListCards[x]))
                        .ToArray();


// How to shuffle deck
Random r = new Random();
Array.Sort(deck, (a, b) => r.Next(0, 2) == 0 ? -1 : 1);

// How to reset deck
Array.Sort(deck);

// How to display top five cards
pictureBox_Card1.Image = deck[0].CardImage;
pictureBox_Card2.Image = deck[1].CardImage;
pictureBox_Card3.Image = deck[2].CardImage;
pictureBox_Card4.Image = deck[3].CardImage;
pictureBox_Card5.Image = deck[4].CardImage;
 
 清单实施 
 
// How to initialize deck
List<PlayingCard> deck = Enumerable.Range(0, 52)
                        .Select(x => new PlayingCard(x % 13, x / 13, imageListCards[x]))
                        .ToList();


// How to shuffle deck
Random r = new Random();
deck.Sort((a, b) => r.Next(0, 2) == 0 ? -1 : 1);

// How to reset deck
deck.Sort();

// How to display top five cards
pictureBox_Card1.Image = deck[0].CardImage;
pictureBox_Card2.Image = deck[1].CardImage;
pictureBox_Card3.Image = deck[2].CardImage;
pictureBox_Card4.Image = deck[3].CardImage;
pictureBox_Card5.Image = deck[4].CardImage;
 
 编辑： 
 
 手动混洗 
 
 如果你想手动进行洗牌，有一个简单的算法叫做Fisher-Yates Shuffle ，它可以做到这一点： 
 
private static Random r = new Random();
static void Shuffle<T>(T[] array)
{
    for (int i = 0; i < array.Length; i++)
    {
        int idx = r.Next(i, array.Length);
        T temp = array[idx];
        array[idx] = array[i];
        array[i] = temp;
    }
}
 
 （列表实施） 
 
private static Random r = new Random();
static void Shuffle<T>(List<T> list)
{
    for (int i = 0; i < list.Count; i++)
    {
        int idx = r.Next(i, list.Count);
        T temp = list[idx];
        list[idx] = list[i];
        list[i] = temp;
    }
}

I'm not sure how your PlayingCard class is coded, but it seems like a large portion of your problems stem from its design. Take this implementation for example:
 
PlayingCard Class
 
public class PlayingCard : IComparable<PlayingCard>
{
    private int value;
    private int suit;
    private Bitmap cardImage;

    public int Value => value;
    public string ValueName => ValueToName(value);

    public int Suit => suit;
    public string SuitName => SuitToName(suit);

    public Bitmap CardImage => cardImage;

    public PlayingCard(int value, int suit, Bitmap cardImage)
    {
        this.value = value;
        this.suit = suit;
        this.cardImage = cardImage;
    }

    private string ValueToName(int n)
    {
        switch (n)
        {
            case 0:
                return "Ace";
            case 1:
            case 2:
            case 3:
            case 4:
            case 5:
            case 6:
            case 7:
            case 8:
            case 9:
                return (n+1).ToString();
            case 10:
                return "Jack";
            case 11:
                return "Queen";
            case 12:
                return "King";
            default:
                throw new ArgumentException("Unrecognized card value.");

        }
    }

    private string SuitToName(int s)
    {
        switch (s)
        {
            case 0:
                return "Clubs";
            case 1:
                return "Diamonds";
            case 2:
                return "Spades";
            case 3:
                return "Hearts";
            default:
                throw new ArgumentException("Unrecognized card suit");
        }
    }

    public int CompareTo(PlayingCard other)
    {
        int result = this.Suit.CompareTo(other.Suit);

        if (result != 0)
            return result;

        return this.Value.CompareTo(other.Value);
    }

    public override string ToString()
    {
        return String.Format("{0} of {1}", ValueName, SuitName);
    }
}
 
It has all the comparison and value conversion coded within it, so you don't have to worry about creating highly specialized methods to do extraneous conversions. You can use it in a deck like so:
 
Array Implementation
 
// How to initialize deck
PlayingCard[] deck = Enumerable.Range(0, 52)
                        .Select(x => new PlayingCard(x % 13, x / 13, imageListCards[x]))
                        .ToArray();


// How to shuffle deck
Random r = new Random();
Array.Sort(deck, (a, b) => r.Next(0, 2) == 0 ? -1 : 1);

// How to reset deck
Array.Sort(deck);

// How to display top five cards
pictureBox_Card1.Image = deck[0].CardImage;
pictureBox_Card2.Image = deck[1].CardImage;
pictureBox_Card3.Image = deck[2].CardImage;
pictureBox_Card4.Image = deck[3].CardImage;
pictureBox_Card5.Image = deck[4].CardImage;
 
List Implementation
 
// How to initialize deck
List<PlayingCard> deck = Enumerable.Range(0, 52)
                        .Select(x => new PlayingCard(x % 13, x / 13, imageListCards[x]))
                        .ToList();


// How to shuffle deck
Random r = new Random();
deck.Sort((a, b) => r.Next(0, 2) == 0 ? -1 : 1);

// How to reset deck
deck.Sort();

// How to display top five cards
pictureBox_Card1.Image = deck[0].CardImage;
pictureBox_Card2.Image = deck[1].CardImage;
pictureBox_Card3.Image = deck[2].CardImage;
pictureBox_Card4.Image = deck[3].CardImage;
pictureBox_Card5.Image = deck[4].CardImage;
 
EDIT: 
 
Manual Shuffling
 
If you want to do a shuffle manually, there's a simple algorithm called the Fisher-Yates Shuffle that will do the trick:
 
private static Random r = new Random();
static void Shuffle<T>(T[] array)
{
    for (int i = 0; i < array.Length; i++)
    {
        int idx = r.Next(i, array.Length);
        T temp = array[idx];
        array[idx] = array[i];
        array[i] = temp;
    }
}
 
(List Implementation)
 
private static Random r = new Random();
static void Shuffle<T>(List<T> list)
{
    for (int i = 0; i < list.Count; i++)
    {
        int idx = r.Next(i, list.Count);
        T temp = list[idx];
        list[idx] = list[i];
        list[i] = temp;
    }
}