//版本一：吃完一个就结束了。unit Unit1;interfaceuses  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants,  System.Classes, Vcl.Graphics, Vcl.Controls, Vcl.Forms, Vcl.Dialogs,  Vcl.ExtCtrls;type  TForm1 = class(TForm)    Timer1: TTimer;    procedure FormCreate(Sender: TObject);    procedure FormKeyDown(Sender: TObject; var Key: Word; Shift: TShiftState);    procedure Timer1Timer(Sender: TObject);    procedure FormPaint(Sender: TObject);  private    { Private declarations }    Snake: array[0..499] of TPoint;    SnakeLength: Integer;    Food: TPoint;    Direction: TPoint;    procedure DrawSnake;    procedure DrawFood;    procedure MoveSnake;    procedure CheckCollision;  public    { Public declarations }  end;var  Form1: TForm1;implementation{$R *.dfm}const  BlockSize = 10;procedure TForm1.FormCreate(Sender: TObject);begin  SnakeLength := 1;  Snake[0].X := 10;  Snake[0].Y := 10;  Food.X := 30;  Food.Y := 30;  Direction.X := 1;  Direction.Y := 0;  Timer1.Enabled := True;  DoubleBuffered := True;end;procedure TForm1.FormKeyDown(Sender: TObject; var Key: Word; Shift: TShiftState);begin  case Key of    VK_UP:      begin        Direction.X := 0;        Direction.Y := -1;      end;    VK_DOWN:      begin        Direction.X := 0;        Direction.Y := 1;      end;    VK_LEFT:      begin        Direction.X := -1;        Direction.Y := 0;      end;    VK_RIGHT:      begin        Direction.X := 1;        Direction.Y := 0;      end;  end;end;procedure TForm1.FormPaint(Sender: TObject);begin  DrawSnake;  DrawFood;end;procedure TForm1.Timer1Timer(Sender: TObject);begin  MoveSnake;  CheckCollision;  Repaint;end;procedure TForm1.DrawSnake;var  i: Integer;begin  for i := 0 to SnakeLength - 1 do  begin    Canvas.Brush.Color := clGreen;    Canvas.FillRect(Rect(Snake[i].X * BlockSize, Snake[i].Y * BlockSize,    Snake[i].X * BlockSize + BlockSize, Snake[i].Y * BlockSize + BlockSize));  end;end;procedure TForm1.DrawFood;begin  Canvas.Brush.Color := clRed;  Canvas.FillRect(Rect(Food.X * BlockSize, Food.Y * BlockSize,  Food.X * BlockSize + BlockSize, Food.Y * BlockSize + BlockSize));end;procedure TForm1.MoveSnake;var  i: Integer;begin  for i := SnakeLength - 1 downto 1 do    Snake[i] := Snake[i - 1];  Snake[0].X := Snake[0].X + Direction.X;  Snake[0].Y := Snake[0].Y + Direction.Y;end;procedure TForm1.CheckCollision;var  i: Integer;begin  if (Snake[0].X = Food.X) and (Snake[0].Y = Food.Y) then  begin    Inc(SnakeLength);    Snake[SnakeLength - 1] := Snake[SnakeLength - 2];    Food.X := Random(ClientWidth div BlockSize);    Food.Y := Random(ClientHeight div BlockSize);  end;  if Snake[0].X < 0 then    Snake[0].X := ClientWidth div BlockSize - 1;  if Snake[0].X > ClientWidth div BlockSize - 1 then    Snake[0].X := 0;  if Snake[0].Y < 0 then    Snake[0].Y := ClientHeight div BlockSize - 1;  if Snake[0].Y > ClientHeight div BlockSize - 1 then    Snake[0].Y := 0;  for i := 1 to SnakeLength - 1 do    if (Snake[0].X = Snake[i].X) and (Snake[0].Y = Snake[i].Y) then      Timer1.Enabled := False;end;end.

// 吃完第一个食物就完了。哈哈。于是要求写一个完善一点的。

存在一些小问题，稍微改了一下，可以运行，还算完美。

版本二：

unit Unit1;interfaceuses  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants,  System.Classes, Vcl.Graphics, Vcl.Controls, Vcl.Forms, Vcl.Dialogs,  Vcl.ExtCtrls, Vcl.StdCtrls;type  TDirection = (dLeft, dUp, dRight, dDown);  TSnake = array[0..100] of TPoint;type  TForm1 = class(TForm)    Timer1: TTimer;    Button1: TButton;    procedure FormCreate(Sender: TObject);    procedure FormKeyDown(Sender: TObject; var Key: Word; Shift: TShiftState);    procedure Timer1Timer(Sender: TObject);    procedure Paint; override;    procedure Button1Click(Sender: TObject);  private    { Private declarations }    procedure MoveSnake;    procedure DrawSnake;    procedure CheckCollision;  public    { Public declarations }  end;var  Form1: TForm1;  Snake: TSnake;  SnakeLength: Integer;  Direction: TPoint;  Food: TPoint;  BlockSize: Integer;implementation{$R *.dfm}procedure TForm1.FormCreate(Sender: TObject);begin  Randomize;  SnakeLength := 5;  BlockSize := 10;  Snake[0].X := ClientWidth div BlockSize div 2;  Snake[0].Y := ClientHeight div BlockSize div 2;  Food.X := Random(ClientWidth div BlockSize);  Food.Y := Random(ClientHeight div BlockSize);  Direction.X := 1;  Direction.Y := 0;end;procedure TForm1.FormKeyDown(Sender: TObject; var Key: Word; Shift: TShiftState);begin  case Key of    VK_LEFT:      if Direction.X <> 1 then      begin        Direction.X := -1;        Direction.Y := 0;      end;    VK_UP:      if Direction.Y <> 1 then      begin        Direction.X := 0;        Direction.Y := -1;      end;    VK_RIGHT:      if Direction.X <> -1 then      begin        Direction.X := 1;        Direction.Y := 0;      end;    VK_DOWN:      if Direction.Y <> -1 then      begin        Direction.X := 0;        Direction.Y := 1;      end;  end;end;procedure TForm1.Timer1Timer(Sender: TObject);begin  MoveSnake;  CheckCollision;  Repaint;end;procedure TForm1.Button1Click(Sender: TObject);begin  Timer1.Enabled := True;end;procedure TForm1.DrawSnake;var  i: Integer;begin  Canvas.Pen.Color := clBlack;  Canvas.Brush.Color := clGreen;  for i := 0 to SnakeLength - 1 do    Canvas.Rectangle(Snake[i].X * BlockSize, Snake[i].Y * BlockSize, Snake[i].X * BlockSize + BlockSize, Snake[i].Y * BlockSize + BlockSize);  Canvas.Brush.Color := clRed;  Canvas.Rectangle(Food.X * BlockSize, Food.Y * BlockSize, Food.X * BlockSize + BlockSize, Food.Y * BlockSize + BlockSize);end;procedure TForm1.MoveSnake;var  i: Integer;begin  for i := SnakeLength - 1 downto 1 do    Snake[i] := Snake[i - 1];  Snake[0].X := Snake[0].X + Direction.X;  Snake[0].Y := Snake[0].Y + Direction.Y;end;procedure TForm1.CheckCollision;var  i: Integer;begin  if (Snake[0].X >= ClientWidth div BlockSize) or (Snake[0].X < 0) or (Snake[0].Y >= ClientHeight div BlockSize) or (Snake[0].Y < 0) then  begin    Timer1.Enabled := False;    ShowMessage('Game Over');  end;  for i := 1 to SnakeLength - 1 do    if Snake[0].X = Snake[i].X then      if Snake[0].Y = Snake[i].Y then      begin        Timer1.Enabled := False;        ShowMessage('Game Over');      end;  if Snake[0].X = Food.X then    if Snake[0].Y = Food.Y then    begin      Inc(SnakeLength);      Food.X := Random(ClientWidth div BlockSize);      Food.Y := Random(ClientHeight div BlockSize);    end;end;procedure TForm1.Paint;var  i: Integer;begin  inherited;  Canvas.Pen.Color := clBlack;  Canvas.Brush.Color := clGreen;  for i := 0 to SnakeLength - 1 do    Canvas.Rectangle(Snake[i].X * BlockSize, Snake[i].Y * BlockSize, Snake[i].X * BlockSize + BlockSize, Snake[i].Y * BlockSize + BlockSize);  Canvas.Brush.Color := clRed;  Canvas.Rectangle(Food.X * BlockSize, Food.Y * BlockSize, Food.X * BlockSize + BlockSize, Food.Y * BlockSize + BlockSize);end;end.

object Form1: TForm1  Left = 0  Top = 0  Caption = 'Form1'  ClientHeight = 455  ClientWidth = 656  Color = clBtnFace  Font.Charset = DEFAULT_CHARSET  Font.Color = clWindowText  Font.Height = -11  Font.Name = 'Tahoma'  Font.Style = []  KeyPreview = True  OldCreateOrder = False  OnCreate = FormCreate  OnKeyDown = FormKeyDown  PixelsPerInch = 96  TextHeight = 13  object Button1: TButton    Left = 504    Top = 24    Width = 75    Height = 25    Caption = 'Button1'    TabOrder = 0    Visible = False    OnClick = Button1Click  end  object Timer1: TTimer    Interval = 100    OnTimer = Timer1Timer    Left = 304    Top = 256  endend

第三版，让他加上了网格。没有大问题，有些小细节要自己修改。

unit Unit1;interfaceuses  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants,  System.Classes, Vcl.Graphics, Vcl.Controls, Vcl.Forms, Vcl.Dialogs,  Vcl.ExtCtrls, Vcl.StdCtrls;type  TDirection = (dLeft, dUp, dRight, dDown);  TSnake = array[0..100] of TPoint;type  TForm1 = class(TForm)    Timer1: TTimer;    Button1: TButton;    procedure FormCreate(Sender: TObject);    procedure FormKeyDown(Sender: TObject; var Key: Word; Shift: TShiftState);    procedure Timer1Timer(Sender: TObject);    procedure Paint; override;    procedure Button1Click(Sender: TObject);  private    { Private declarations }    procedure MoveSnake;    procedure DrawSnake;    procedure DrawGrid;    procedure CheckCollision;  public    { Public declarations }  end;var  Form1: TForm1;  Snake: TSnake;  SnakeLength: Integer;  Direction: TPoint;  Food: TPoint;  BlockSize: Integer = 10;  PlayFieldSize: Integer;implementation{$R *.dfm}procedure TForm1.FormCreate(Sender: TObject);begin  Randomize;  SnakeLength := 5;  self.Height := self.Width;  PlayFieldSize := self.Width div BlockSize - 1;  Snake[0].X := ClientWidth div BlockSize div 2;  Snake[0].Y := ClientHeight div BlockSize div 2;  Food.X := Random(ClientWidth div BlockSize);  Food.Y := Random(ClientHeight div BlockSize);  Direction.X := 1;  Direction.Y := 0;end;procedure TForm1.FormKeyDown(Sender: TObject; var Key: Word; Shift: TShiftState);begin  case Key of    VK_LEFT:      if Direction.X <> 1 then      begin        Direction.X := -1;        Direction.Y := 0;      end;    VK_UP:      if Direction.Y <> 1 then      begin        Direction.X := 0;        Direction.Y := -1;      end;    VK_RIGHT:      if Direction.X <> -1 then      begin        Direction.X := 1;        Direction.Y := 0;      end;    VK_DOWN:      if Direction.Y <> -1 then      begin        Direction.X := 0;        Direction.Y := 1;      end;  end;end;procedure TForm1.Timer1Timer(Sender: TObject);begin  MoveSnake;  CheckCollision;  Repaint;end;procedure TForm1.Button1Click(Sender: TObject);begin  Timer1.Enabled := True;end;procedure TForm1.DrawGrid;var  i: Integer;begin  Canvas.Pen.Color := clBlack;  for i := 0 to PlayFieldSize do  begin    Canvas.MoveTo(i * BlockSize, 0);    Canvas.LineTo(i * BlockSize, PlayFieldSize * BlockSize);    Canvas.MoveTo(0, i * BlockSize);    Canvas.LineTo(PlayFieldSize * BlockSize, i * BlockSize);  end;end;procedure TForm1.DrawSnake;var  i: Integer;begin  Canvas.Pen.Color := clBlack;  Canvas.Brush.Color := clGreen;  for i := 0 to SnakeLength - 1 do    Canvas.Rectangle(Snake[i].X * BlockSize,      Snake[i].Y * BlockSize,      Snake[i].X * BlockSize + BlockSize,      Snake[i].Y * BlockSize + BlockSize);  Canvas.Brush.Color := clRed;  Canvas.Rectangle(Food.X * BlockSize, Food.Y * BlockSize,    Food.X * BlockSize + BlockSize, Food.Y * BlockSize + BlockSize);end;procedure TForm1.MoveSnake;var  i: Integer;begin  for i := SnakeLength - 1 downto 1 do    Snake[i] := Snake[i - 1];  Snake[0].X := Snake[0].X + Direction.X;  Snake[0].Y := Snake[0].Y + Direction.Y;end;procedure TForm1.CheckCollision;var  i: Integer;begin  if (Snake[0].X >= ClientWidth div BlockSize) or (Snake[0].X < 0) or (Snake[0].Y >= ClientHeight div BlockSize) or (Snake[0].Y < 0) then  begin    Timer1.Enabled := False;    ShowMessage('Game Over');  end;  for i := 1 to SnakeLength - 1 do    if Snake[0].X = Snake[i].X then      if Snake[0].Y = Snake[i].Y then      begin        Timer1.Enabled := False;        ShowMessage('Game Over');      end;  if Snake[0].X = Food.X then    if Snake[0].Y = Food.Y then    begin      Inc(SnakeLength);      Food.X := Random(ClientWidth div BlockSize);      Food.Y := Random(ClientHeight div BlockSize);    end;end;procedure TForm1.Paint;var  i: Integer;begin  inherited;  DrawGrid;  Canvas.Pen.Color := clBlack;  Canvas.Brush.Color := clGreen;  for i := 0 to SnakeLength - 1 do    Canvas.Rectangle(Snake[i].X * BlockSize, Snake[i].Y * BlockSize, Snake[i].X * BlockSize + BlockSize, Snake[i].Y * BlockSize + BlockSize);  Canvas.Brush.Color := clRed;  Canvas.Rectangle(Food.X * BlockSize, Food.Y * BlockSize, Food.X * BlockSize + BlockSize, Food.Y * BlockSize + BlockSize);end;end.