为什么不能释放内存，而且很有可能蓝屏、死机呢？

Question

请求：
我想利用这个程序实现双缓冲移动图片的功能，而且想在当图片运行到Form外的时候就把图片给释放掉，可是好像我运行的时候电脑总是迟疑了一段时间哦，也就是说这段时间相当于死机了。而且我竟然还有那么几次蓝屏哦，麻烦大家帮我看看，多谢了！
unit Unit1;interfaceuses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, ExtCtrls;type
  TForm1 = class(TForm)
    Timer1: TTimer;
    Button2: TButton;
    Button3: TButton;
    Button1: TButton;
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
    procedure Timer1Timer(Sender: TObject);
    procedure Button1Click(Sender: TObject);  private    procedure MoveImage;
    { Private declarations }
  public
    { Public declarations }
    FBitMap:TBitMap;//保存图形
    FBitMapBuff:TBitMap;//缓冲区
    FActivePoint:TPoint;//当前移动到的位置
    FMoveXSpace:integer;//X方向要移动的距离
    FMoveYSpace:integer;//Y方向要移动的距离
    FStop:Boolean;
    a:integer;
  end;var
  Form1: TForm1;implementation{$R *.dfm}
function GetRandomSpace:integer;
begin
//返回一个随机的移动距离
Randomize;
Result:=Random(2);
end;procedure TForm1.MoveImage;
begin
  FBitMapBuff:=TBitMap.Create;
  FBitMap:=TBitMap.Create;
//缓冲区图大小和Form1大小相同  就是说在整个Form中画图
  FBitMapBuff.Width:=Form1.Width;
  FBitMapBuff.Height:=Form1.Height;
  FBitMap.LoadFromFile('Car1.bmp');
//先绘制缓冲区的图形
with FBitMapBuff do
  begin
    FreeImage;
    CleanupInstance;
    Canvas.FillRect(Rect(0,0,FBitMapBuff.Width,FBitMapBuff.Height));
    Canvas.Draw(a,0,FBitMap);            
    a:=a+5;
  end;
//然后直接给Image绘制
  Form1.Canvas.Draw(0,0,FBitMapBuff);
  if a>=500 then
    begin
      timer1.Enabled:=not timer1.Enabled;
    end;
  FBitMap.Free;
  FBitMapBuff.Free;
end;procedure TForm1.Button2Click(Sender: TObject);
begin
  FStop:=not FStop;
while FStop do 
  begin
    MoveImage;
    Application.ProcessMessages; 
  end;
end;procedure TForm1.Button3Click(Sender: TObject);
begin
  Timer1.Enabled:=Not Timer1.Enabled;
end;procedure TForm1.Timer1Timer(Sender: TObject);
begin
  MoveImage;
end;procedure TForm1.Button1Click(Sender: TObject);
begin
  Close;
  Application.terminate;
end;
end.
人家告诉我去使用设置断点，可是我用了还是不能发现错误到底出现在哪里哦！悬赏你50分

Answer 1

最起码有2点:
1\为什么要用CleanupInstance;
{Do not call CleanupInstance directly. CleanupInstance is called automatically when the object instance is destroyed.CleanupInstance releases all long strings and variants. It sets long strings to empty and variants to Unassigned.}2\你这种情况根本就不需要用内存缓冲图,因为只有一次绘制动作:Canvas.Draw(...); 

Answer 2

procedure TForm1.MoveImage; 
begin 
  FBitMapBuff:=TBitMap.Create; 
  FBitMap:=TBitMap.Create; 
//缓冲区图大小和Form1大小相同  就是说在整个Form中画图 
  FBitMapBuff.Width:=Form1.Width; 
  FBitMapBuff.Height:=Form1.Height; 
  FBitMap.LoadFromFile('Car1.bmp'); 
//先绘制缓冲区的图形 
with FBitMapBuff do 
  begin 
    FreeImage; 
    CleanupInstance; 
    Canvas.FillRect(Rect(0,0,FBitMapBuff.Width,FBitMapBuff.Height)); 
    Canvas.Draw(a,0,FBitMap);
刚创建的FBitMapBuff你干嘛又FreeImage又CleanupInstance，而且你都CleanupInstance后面使用程序运行时不产生错误吗？

Answer 3

http://blog.csdn.net/ZyxIp/archive/2007/03/30/1546379.aspx
用双缓冲实现图形的移动

Answer 4

unit Unit1;interfaceuses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, ExtCtrls;type
  TForm1 = class(TForm)
    Image1: TImage;
    Timer1: TTimer;
    Button2: TButton; 
    Button3: TButton;
    procedure FormCreate(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
    procedure Timer1Timer(Sender: TObject);
  private
    procedure RefreshActivePoint;
    procedure MoveImage;
    { Private declarations }
  public
    { Public declarations }
    FBitMap:TBitMap; //保存图形
    FBitMapBuff:TBitMap; //缓冲区
    FActivePoint:TPoint; //当前移动到的位置
    FMoveXSpace:Integer; //X方向要移动的距离
    FMoveYSpace:Integer; //Y方向要移动的距离
    FStop:Boolean;
  end;
var
  Form1: TForm1;implementation{$R *.dfm}procedure TForm1.FormCreate(Sender: TObject);
begin
  FBitMapBuff:=TBitmap.Create;
  FBitMap:=TBitmap.Create;
  //缓冲区图大小和Image1大小相同
  FBitMapBuff.Width:=Image1.Width;
  FBitMapBuff.Height:=Image1.Height;
  FBitMap.LoadFromFile('D:\Winnt\Greenstone.bmp');
  FActivePoint:=Point(0,0);
  FMoveXSpace:=10;
  FMoveYSpace:=10;
end;function  GetRandomSpace:Integer;
begin
//返回一个随机的移动距离
  Randomize;
  Result:=Random(30);
end;procedure TForm1.RefreshActivePoint;
begin
   //检查移动边界,确定下一个要移动到的位置
  if (FActivePoint.X+FBitMap.Width>=Image1.Width) then
    FMoveXSpace:=0-GetRandomSpace
  else if FActivePoint.X<=0 then
    FMoveXSpace:=GetRandomSpace;  if FActivePoint.Y+FBitMap.Height>=Image1.Height then
    FMoveYSpace:=0-GetRandomSpace
  else if FActivePoint.Y<=0 then
    FMoveYSpace:=GetRandomSpace;
  FActivePoint:=Point(FActivePoint.X+FMoveXSpace,FActivePoint.Y+FMoveYSpace);  if FActivePoint.X+FBitMap.Width>Image1.Width then
    FActivePoint.X:=FActivePoint.X-(FActivePoint.X+FBitMap.Width-Image1.Width)
  else if FActivePoint.X<0 then
    FActivePoint.X:=0;  if FActivePoint.Y+FBitMap.Height>Image1.Height then
    FActivePoint.Y:=FActivePoint.Y-(FActivePoint.Y+FBitMap.Height-Image1.Height)
  else if FActivePoint.Y<0 then
    FActivePoint.Y:=0;
end;procedure  TForm1.MoveImage;
begin
  //先绘制缓冲区中的图形
  With FBitMapBuff do
  begin
    FreeImage;
    CleanupInstance;
    Canvas.FillRect(Rect(0,0,FBitMapBuff.Width,FBitMapBuff.Height));
    Canvas.Draw(FActivePoint.X,FActivePoint.Y,FBitMap);
  end;
  //然后直接给Image 绘制
  Image1.Canvas.Draw(0,0,FBitMapBuff);
  RefreshActivePoint;
end;procedure TForm1.Button2Click(Sender: TObject);
begin
//循环移动
  FStop:=Not FStop;
  while FStop do
  begin
    MoveImage;
    Application.ProcessMessages;
  end;
end;procedure TForm1.Button3Click(Sender: TObject);
begin
//定时器移动
  Timer1.Enabled:=Not Timer1.Enabled;
end;procedure TForm1.Timer1Timer(Sender: TObject);
begin
  MoveImage;
end;end. 
本文来自CSDN博客，转载请标明出处：http://blog.csdn.net/ZyxIp/archive/2007/03/30/1546379.aspx
借用一下你的程序哦
procedure  TForm1.MoveImage;
begin
  //先绘制缓冲区中的图形
  With FBitMapBuff do
  begin
    FreeImage;
    CleanupInstance;
很多人都属这个什么FreeImage,与CleanupInstance哦，都说不用，可是就是这个程序中就是有哦！你说呢？