从类传递值以不同的形式显示以编程方式处理单击事件？

Question

我目前创建了一个国际象棋棋盘，其中填充了棋子的图像，并对棋盘进行了着色等，我在点击事件方法方面有两个问题，希望您能帮助我解决？当单击一个方块时，我当前的方法会更改方块颜色并显示一个消息框，其中显示 xy 坐标和块类型，或者如果它没有被块占据，则仅显示坐标：

问题 1：如何更改颜色如果我再次单击同一个正方形或不同的正方形，回到原来的状态？

问题 2：如何在文本框或标签中显示 Form1.cs 上的信息，而不是显示消息框？

以下是我的 GridSqaure.cs 类中的代码：

namespace Chess
{
    public class GridSquare : PictureBox
    {
        private int x;
        private int y;

        private ChessPiece piece;

        public int X { get { return x; } }
        public int Y { get { return y; } }

        public ChessPiece Piece 
        {
            get { return piece; }
            set 
            {
                piece = value;
                if (value == null)
                    this.BackgroundImage = null;
                else
                    this.BackgroundImage = piece.GetImage();
            }
        }

        public GridSquare(int x, int y)
        {
            int ButtonWidth = 64;
            int ButtonHeight = 64;
            int Distance = 20;
            int start_x = 10;
            int start_y = 10;

            this.x = x;
            this.y = y;

            this.Top = start_x + (x * ButtonHeight + Distance + x);
            this.Left = start_y + (y * ButtonWidth + Distance + y);
            this.Width = ButtonWidth;
            this.Height = ButtonHeight;
            this.Text = "X: " + x.ToString() + " Y: " + y.ToString();

            this.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle;

            this.Click += new System.EventHandler(gridSquare_Click);
        }

        private void gridSquare_Click(object sender, EventArgs e)
        {
            GridSquare gs = (GridSquare)sender;
            if (gs.Piece != null)
                {
                    //Change: need to show xy of sqaure clicked on a label or textbox on the main window.
                MessageBox.Show("You clicked a " + gs.Piece.GetName() + " at (" + gs.X + ", " + gs.Y + ")");

                //Change: need to click for change in colour, then second click to revert back
                this.BackColor = Color.LightBlue;
                } 
            else
                {
                    //Change: need to show xy of clicked square but including meesage stating the sqaure needs to be occupied by a piece.
                    MessageBox.Show("You clicked (" + gs.X + ", " + gs.Y + ")");
                }
        }
    }
}

Answer 1

我会避免让一个类处理它自己的事件之一。这不是一个好的做法。

相反，我会使用回调策略。

首先，像这样重新编码 GridSquare：

public class GridSquare : PictureBox
{
    /* As before */

    public GridSquare(int x, int y, Action<GridSquare> clicked)
    {
        /* As before */
        this.Click += (s, e) => clicked(this);
    }

    /* NO private void gridSquare_Click(object sender, EventArgs e) */
}

现在由调用代码来完成艰苦的工作。

我假设您正在使用类似嵌套 for 循环之类的东西来创建板，该循环将每个创建的 GridSquare 添加到表单的 Controls 集合中。如果是这种情况，您需要像这样编写代码：

for (var x = 0; x < 8; x++)
{
    for (var y = 0; y < 8; y++)
    {
        this.Controls.Add(new GridSquare(x, y, clicked));
    }
}

现在您只需要定义 clicked - 单击每个 GridSquare 时的回调 - 该代码如下所示：

GridSquare lastClicked = null;
Color lastBackColor = Color.Transparent;

Action<GridSquare> clicked = gs =>
{
    lastClicked.BackColor = lastBackColor;
    if (!lastClicked.Equals(gs))
    {
        lastClicked = gs;
        lastBackColor = gs.BackColor;
        gs.BackColor = Color.LightBlue;
        var inner = gs.Piece != null
            ? String.Format("a {0} at ", gs.Piece.GetName())
            : "";
        var msg = String.Format("You clicked {0}({1}, {2})", inner, gs.X, gs.Y);
        MessageBox.Show(msg);
    }
};

显然，这段代码是在创建网格方块之前执行的。

这应该相对容易理解，但如果不是，请询问，我会详细说明。

让我知道这是否适合您。

Answer 2

首先将盒子的实际颜色存储在 Color 类的对象中，假设对象名称为“BoxColor”，现在看下面的代码。

if (gs.Piece != null) 
{      
    //Change: need to show xy of sqaure clicked on a label or textbox on the main window.       
    label1.Text = "You clicked a " + gs.Piece.GetName() + " at (" + gs.X + ", " + gs.Y + ")";       
   //Change: need to click for change in colour, then second click to revert back           
  this.BackColor = Color.LightBlue;  
}        
else         
{             
    //Change: need to show xy of clicked square but including meesage stating the sqaure needs to be occupied by a piece.   
     this.BackColor = BoxColor //setting back the original color if the box is clicked again.
     label1.Text = "You clicked (" + gs.X + ", " + gs.Y + ")";     
} 

并且还放置一个布尔变量，仅当框的颜色从其实际颜色更改时才启用它，现在如果用户单击任何其他框，请检查这些标志，如果其为 true，则重置颜色。

Answer 3

1. 您可以在类 GridSquare 的范围内创建一个 boolean 变量。然后在 gridSquare_Click 事件处理程序上使用此变量，如下所示：

   公共类 GridSquare : PictureBox
   {
      布尔 isFirstClick = true;
      ……
      ……
      ……
      私人无效gridSquare_Click（对象发送者，EventArgs e）
       {
              if(是第一次点击)
              {
                  isFirstClick = false; 
                  //设置一种颜色
               }
              别的
              {
                  isFirstClick = true;
                  //设置其他颜色
              } 
        } 
   }
   

2. 只需使用 Label 或 TextBox 的 Text 属性.

Answer 4

这就是我将原始代码修改为：

namespace Chess
{
public class GridSquare : PictureBox
{
    private int x;
    private int y;

    private static GridSquare lastClicked;
    private static ChessBoard board;

    private ChessPiece piece;

    public int X { get { return x; } }
    public int Y { get { return y; } }
    public static ChessBoard Board { set { board = value; } }

    Color LightTile = Color.Beige;
    Color DarkTile = Color.SandyBrown;

    public ChessPiece Piece 
    {
        get { return piece; }
        set 
        {
            piece = value;
            if (value == null)
                this.BackgroundImage = null;
            else
                this.BackgroundImage = piece.GetImage();
        }
    }

    public GridSquare(int x, int y)
    {
        int ButtonWidth = 64;
        int ButtonHeight = 64;
        int Distance = 20;
        int start_x = 10;
        int start_y = 10;

        this.x = x;
        this.y = y;

        this.Top = start_x + (x * ButtonHeight + Distance + x);
        this.Left = start_y + (y * ButtonWidth + Distance + y);
        this.Width = ButtonWidth;
        this.Height = ButtonHeight;
        this.Text = "X: " + x.ToString() + " Y: " + y.ToString();

        this.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle;

        this.Click += new System.EventHandler(gridSquare_Click);
    }

    private void gridSquare_Click(object sender, EventArgs e)
    {
        GridSquare gs = (GridSquare)sender;

        if (lastClicked != null)
            lastClicked.ResetColour();

        //Change: need to click for change in colour, then second click to revert back
        this.BackColor = Color.LightBlue;
        lastClicked = this;

        if (gs.Piece != null)
        {
            board.StatusLabel.Text = "You clicked a " + gs.Piece.GetName() + " at (" + gs.X + ", " + gs.Y + ")";
        }
        else
        {
            board.StatusLabel.Text = "You clicked (" + gs.X + ", " + gs.Y + ")";
        }
    }

    public void ResetColour()
    {
        if (x % 2 == 0)
            if (y % 2 == 0)
                // If x=Even y=Even
                this.BackColor = LightTile;
            else
                // If x=Even y=Odd
                this.BackColor = DarkTile;
        else
            if (y % 2 == 0)
                // If x=Odd y=Even
                this.BackColor = DarkTile;
            else
                // If x=Odd y=Odd
                this.BackColor = LightTile;
    }
}

}