Delphi TPngImage内存泄漏

Question

我有一条记录，如下所示：

TCell = record
  Marked:     Boolean;
  ToBeMarked: Boolean;
  Image:      TPngImage;
  end;

var Cells: array of array of TCell

Cells [n] .Image在某个过程中创建，然后存储供以后使用。每次调用该过程时，都会清除此数组。 但是，在关闭程序时，我仍然会收到内存泄漏报告。

unit Unit1;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, pngimage, Vcl.StdCtrls;

type
TCell = record
  Marked:     Boolean;
  ToBeMarked: Boolean;
  Image:      TPngImage;
  end;
  TForm1 = class(TForm)
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
    procedure  TestProcedure1;
    procedure  TestProcedure2(X,Y: Integer);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;
  Cells: array of array of TCell;
  RI_LengthX: Integer;
  RI_LengthY: Integer;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
begin
TestProcedure1;
end;

procedure TForm1.TestProcedure1;
var X,Y: Integer;
begin
{ Clearing the array before the new cycle }
for X:=0 to High(Cells) do for Y:=0 to High(Cells[X]) do     Cells[X,Y].Image.Free;
SetLength(Cells,0);
{ Creating new array }
RI_LengthX:=10;
RI_LengthY:=10;
SetLength(Cells,RI_LengthX);
for X:=0 to High(Cells) do SetLength(Cells[X],RI_LengthY);
{ Calling the procedure that creates image for every cell }
for X:=0 to RI_LengthX-1 do for Y:=0 to RI_LengthY-1 do     TestProcedure2(X,Y);
end;

procedure TForm1.TestProcedure2(X,Y: Integer);
var BaseBMP: TBitmap;
begin
{ Dynamic creation of an image }
BaseBMP:=TBitmap.Create;
BaseBMP.Width:=25;
BaseBMP.Height:=25;
{ Saving image inside a record }
Cells[X,Y].Image:=TPngImage.Create; // Commenting these lines
Cells[X,Y].Image.Assign(BaseBMP);   // prevents the leak
BaseBMP.Free;
end;

initialization
ReportMemoryLeaksOnShutdown:=True;

end.`

有没有办法避免这种泄漏？

Answer 1

在使用SetLength(Cells,0);之前，您必须执行以下代码

  for i := 0 to High(Cells) do
    Cells[i].Image.Free;