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

namespace WindowsFormsApplication15
{
 public partial class Form1 : Form
 {
  public Form1()
  {
   InitializeComponent();
  }
  const int N = 4;//按鈕的行、列數(shù)
  Button[,] buttons = new Button[N, N];//按鈕的數(shù)組

  private void Form1_Load(object sender, EventArgs e)
  {
   //產(chǎn)生所有按鈕
   GenerateAllButtons();
  }

  private void button1_Click(object sender, EventArgs e)
  {
   //點(diǎn)擊“開始”按鈕，打亂順序
   Shuffle();
  }

  //打亂順序函數(shù)
  void Shuffle()
  {
   //多次隨機(jī)交換兩個(gè)按鈕
   Random rnd = new Random();
   for(int i = 0; i < 100; i++)
   {
    int a = rnd.Next(N);
    int b = rnd.Next(N);
    int c = rnd.Next(N);
    int d = rnd.Next(N);
    Swap(buttons[a, b], buttons[c, d]);//交換兩個(gè)按鈕位置
   }
  }

  //生成所有按鈕函數(shù)
  void GenerateAllButtons()
  {
   int x0 = 100, y0 = 10, w = 45, d = 50;
   for (int r = 0; r < N; r++)
   {
    for (int c = 0; c < N; c++)
    {
     int num = r * N + c;
     Button btn = new Button();
     btn.Text = (num + 1).ToString();//設(shè)置按鈕顯示的數(shù)字
     btn.Top = y0 + r * d;//設(shè)置按鈕的左邊緣與容器的上邊緣之間的距離
     btn.Left = x0 + c * d;//設(shè)置按鈕的左邊緣與容器的左邊緣之間的距離
     btn.Width = w;//按鈕寬度
     btn.Height = w;//按鈕高度
     btn.Visible = true;//是否顯示按鈕
     btn.Tag = r * N + c;//Tag屬性是給程序員自己用的，做點(diǎn)標(biāo)記，類似于按鈕的ID，此處這個(gè)數(shù)據(jù)用來表示它所在的行列位置

     //注冊(cè)事件
     btn.Click += new EventHandler(btn_click);

     buttons[r, c] = btn;//放到數(shù)組中
     this.Controls.Add(btn);//加到界面上
    }
   }
   buttons[N - 1, N - 1].Visible = false;//定義最后一個(gè)按鈕不可見
  }

  //交換兩個(gè)按鈕函數(shù)
  void Swap(Button btna,Button btnb)
  {
   //兩個(gè)按鈕的值交換
   string t = btna.Text;
   btna.Text = btnb.Text;
   btnb.Text = t;

   //兩個(gè)按鈕的可見屬性交換
   bool v = btna.Visible;
   btna.Visible = btnb.Visible;
   btnb.Visible = v;
  }

  //按鈕點(diǎn)擊事件處理
  void btn_click(object sender,EventArgs e)
  {
   Button btn = sender as Button;//當(dāng)前點(diǎn)中的按鈕
   Button blank = FindHiddenButton();//空白按鈕

   //判斷是否與空白按鈕相鄰，如果是，則交換
   if (IsNeighbor(btn,blank))
   {
    Swap(btn, blank);
    blank.Focus();
   }

   //判斷是否完成了游戲
   if (ResultIsOk())
   {
    MessageBox.Show("OK");
   }
  }

  //查找要隱藏的按鈕函數(shù)
  Button FindHiddenButton()
  {
   for (int r = 0; r < N; r++)
   {
    for (int c = 0; c < N; c++)
    {
     if (!buttons[r,c].Visible)
     {
      return buttons[r, c];
     }
    }
   }
   return null;
  }

  //判斷是否相鄰函數(shù)
  bool IsNeighbor(Button btnA,Button btnB)
  {
   int a = (int)btnA.Tag;//獲取Tag中保存的位置信息(0-15的值)
   int b = (int)btnB.Tag;
   int r1 = a / N, c1 = a % N;//算出第幾行第幾列
   int r2 = b / N, c2 = b % N;
   
   //判斷左右相鄰或者上下相鄰
   if ( (r1 == r2 && (c1 == c2 - 1 || c1 == c2 + 1)) || (c1 == c2 && (r1 == r2 - 1 || r1 == r2 + 1)) )
   {
    return true;
   }
   return false;    
  }

  //檢查是否完成
  bool ResultIsOk()
  {
   for (int r = 0; r < N; r++)
   {
    for (int c = 0; c < N; c++)
    {
     if(buttons[r,c].Text != (r * N + c + 1).ToString())
     {
      return false;
     }
    }
   }
   return true;
  }

  private void Btn_Click(object sender, EventArgs e)
  {
   throw new NotImplementedException();
  }
 }
}