拖放拼图游戏

Question

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
public partial class Jigsaw : Form
{
    public Jigsaw()
    {
        InitializeComponent();

        PBoxJigsaw1.MouseDown += PBoxJigsaw1_MouseDown;
        pnlJigsaw1.AllowDrop = true;
        pnlJigsaw1.DragEnter += pnlJigsaw1_DragEnter;

    }

    private void timer1_Tick(object sender, EventArgs e)
    {
        Random rnd = new Random();
        JigsawLabel.ForeColor = Color.FromArgb(rnd.Next(255), rnd.Next(255), rnd.Next(255));
    }

    private void HomeButton_Click(object sender, EventArgs e)
    {
        MainScreen main = new MainScreen();
        main.Show();
        this.Hide();
    }

    private int xPos;
    private int yPos;

    private void PBoxJigsaw1_MouseDown(object sender, MouseEventArgs e)
    {
        var img = PBoxJigsaw1.Image;
        if (img == null) return;
        if (DoDragDrop(img, DragDropEffects.Move) == DragDropEffects.Move)
        {
            PBoxJigsaw1.Image = null;
        }
    }

    private void PBoxJigsaw1_MouseMove(object sender, MouseEventArgs e)
    {
        if (sender != null && sender.GetType() == typeof(PictureBox))
        {
            if (e.Button == System.Windows.Forms.MouseButtons.Left)
            {
                ((PictureBox)sender).Top += (e.Y - yPos);
                ((PictureBox)sender).Left += (e.X - xPos);
                this.Refresh();
            }
        }
    }

    private void PBoxJigsaw1_MouseUp(object sender, MouseEventArgs e)
    {
        if (sender != null && sender.GetType() == typeof(PictureBox))
        {
            if (e.Button == System.Windows.Forms.MouseButtons.Left)
            {
                PictureBox answer = (PictureBox)sender;

                if (answer.Location.X < pnlJigsaw1.Location.X)
                {
                    if (answer.Location.X + answer.Width > pnlJigsaw1.Location.X)
                    {
                        if ((answer.Location.X + answer.Width) < pnlJigsaw1.Location.X + pnlJigsaw1.Width)
                        {
                            answer.Location = pnlJigsaw1.Location;
                        }
                    }
                }
                else if (answer.Location.X < pnlJigsaw2.Location.X)
                {
                    if (answer.Location.X + answer.Width > pnlJigsaw2.Location.X)
                    {
                        if ((answer.Location.X + answer.Width) < pnlJigsaw2.Location.X + pnlJigsaw2.Width)
                        {
                            answer.Location = pnlJigsaw2.Location;
                        }
                    }
                }
                else if (answer.Location.X < pnlJigsaw3.Location.X)
                {
                    if (answer.Location.X + answer.Width > pnlJigsaw3.Location.X)
                    {
                        if ((answer.Location.X + answer.Width) < pnlJigsaw3.Location.X + pnlJigsaw3.Width)
                        {
                            answer.Location = pnlJigsaw3.Location;
                        }
                    }
                }
                else if (answer.Location.X < pnlJigsaw4.Location.X)
                {
                    if (answer.Location.X + answer.Width > pnlJigsaw4.Location.X)
                    {
                        if ((answer.Location.X + answer.Width) < pnlJigsaw4.Location.X + pnlJigsaw4.Width)
                        {
                            answer.Location = pnlJigsaw4.Location;
                        }
                    }
                }
                else if (answer.Location.X < pnlJigsaw5.Location.X)
                {
                    if (answer.Location.X + answer.Width > pnlJigsaw5.Location.X)
                    {
                        if ((answer.Location.X + answer.Width) < pnlJigsaw5.Location.X + pnlJigsaw5.Width)
                        {
                            answer.Location = pnlJigsaw5.Location;
                        }
                    }
                }
                else if (answer.Location.X < pnlJigsaw6.Location.X)
                {
                    if (answer.Location.X + answer.Width > pnlJigsaw6.Location.X)
                    {
                        if ((answer.Location.X + answer.Width) < pnlJigsaw6.Location.X + pnlJigsaw6.Width)
                        {
                            answer.Location = pnlJigsaw6.Location;
                        }
                    }
                }
                else if (answer.Location.X < pnlJigsaw7.Location.X)
                {
                    if (answer.Location.X + answer.Width > pnlJigsaw7.Location.X)
                    {
                        if ((answer.Location.X + answer.Width) < pnlJigsaw7.Location.X + pnlJigsaw7.Width)
                        {
                            answer.Location = pnlJigsaw7.Location;
                        }
                    }
                }
                else if (answer.Location.X < pnlJigsaw8.Location.X)
                {
                    if (answer.Location.X + answer.Width > pnlJigsaw8.Location.X)
                    {
                        if ((answer.Location.X + answer.Width) < pnlJigsaw8.Location.X + pnlJigsaw8.Width)
                        {
                            answer.Location = pnlJigsaw8.Location;
                        }
                    }
                }

            }
        }
    }

    private void pnlJigsaw1_DragEnter(object sender, DragEventArgs e)
    {
        e.Effect = DragDropEffects.All;
        if (e.Data.GetDataPresent(DataFormats.Bitmap))
            e.Effect = DragDropEffects.Move;
    }

    private void pnlJigsaw2_DragEnter(object sender, DragEventArgs e)
    {
        e.Effect = DragDropEffects.All;
    }

    private void pnlJigsaw3_DragEnter(object sender, DragEventArgs e)
    {
        e.Effect = DragDropEffects.All;
    }

    private void pnlJigsaw4_DragEnter(object sender, DragEventArgs e)
    {
        e.Effect = DragDropEffects.All;
    }

    private void pnlJigsaw5_DragEnter(object sender, DragEventArgs e)
    {
        e.Effect = DragDropEffects.All;
    }

    private void pnlJigsaw6_DragEnter(object sender, DragEventArgs e)
    {
        e.Effect = DragDropEffects.All;
    }

    private void pnlJigsaw7_DragEnter(object sender, DragEventArgs e)
    {
        e.Effect = DragDropEffects.All;
    }

    private void pnlJigsaw8_DragEnter(object sender, DragEventArgs e)
    {
        e.Effect = DragDropEffects.All;
    }
}

}

我正在尝试使用拖放操作在应用程序的窗口上制作拼图游戏。我有8个pictureBox和8个面板供picBox使用。上面附带的代码允许我将picBox拖动到前4个面板中，然后它们会卡入到位，但代码无法让piBox卡入底部的4个面板。如果我把面板5的代码，例如，面板1的代码上面，picBox thens卡入面板5而不是面板1.当mouseUp发生时，我是否需要确定pictureBox的位置（可能是y co-纵坐标）？或者我该如何解决这个问题？

提前致谢