理论上，数组的容器就是进程，关闭程序，数组的那块才会释放掉。不像类（如窗体上的的按钮设置了容器即parent，它放在谁的上面，谁在释放之前就会把按钮先释放掉），类的对象有parent、owner这两个的一个就会跟着parent或者owner释放而释放。
直接释放一维会造成内存泄露。setlength了几次就要释放几次！第一个setlength是一维给了一次，二维又setlength给了一次，释放就反过来，先把二维释放，再释放一维。怎么给的空间，就怎么把空间释放掉，不要给程序留下隐患。
但是，测试发现，先释放二维再释放一维与直接释放一维，这二者的效果是一样的（看下面代码的最后2个button的过程代码即可）！！以后对于多维数组的释放问题，直接释放一维数组即可！
释放动态数组可使用下面这3种方式，都可以实现：
SetLength(Myarray,0);
Finalize(Myarray);
Myarray:=nil;
unit Unit1;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls;
type
TForm1 = class(TForm)
Array_01_static: TButton;
Array_01_dynamic: TButton;
Array_02_static: TButton;
Array_02_dynamic: TButton;
Memo1: TMemo;
Button1: TButton;
procedure Array_01_staticClick(Sender: TObject);
procedure Array_01_dynamicClick(Sender: TObject);
procedure Array_02_staticClick(Sender: TObject);
procedure Array_02_dynamicClick(Sender: TObject);
procedure Button1Click(Sender: TObject);
private
myarray02_02:array of array of string;//定義動態二維數組
{ Private declarations }
public
{ Public declarations }
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
procedure TForm1.Array_01_staticClick(Sender: TObject);
var
myarray01_01:array[0..2] of string;
i:Integer;
begin
//myarray01_01[0]:='0_A';
//myarray01_01[1]:='1_A';
//myarray01_01[2]:='2_A';
for i:=Low(myarray01_01) to High(myarray01_01) do
begin
myarray01_01[i]:=IntToStr(i)+'_A';
end;
Memo1.Clear;
for i:=Low(myarray01_01) to High(myarray01_01) do
begin
Memo1.Lines.Add('i= '+IntToStr(i)+' Value: '+myarray01_01[i]);
end;
end;
procedure TForm1.Array_01_dynamicClick(Sender: TObject);
var
myarray01_02:array of string;
i:Integer;
begin
SetLength(myarray01_02,3);
for i:=Low(myarray01_02) to High(myarray01_02) do
begin
myarray01_02[i]:=IntToStr(i)+'_B';
end;
Memo1.Clear;
for i:=Low(myarray01_02) to High(myarray01_02) do
begin
Memo1.Lines.Add('i= '+IntToStr(i)+' Value: '+myarray01_02[i]);
end;
SetLength(myarray01_02,0); //釋放數組空間
end;
procedure TForm1.Array_02_staticClick(Sender: TObject);
var
myarray02_01:array [0..2]of array [0..3]of string;//定義靜態二維數組
i,j,n:Integer;
begin
n:=0;
for i:=Low(myarray02_01) to High(myarray02_01) do
begin
for j:=Low(myarray02_01[i]) to High(myarray02_01[i]) do
begin
Inc(n);
myarray02_01[i][j]:=IntToStr(n)+'_C'
end;
end;
Memo1.Clear;
for i:=Low(myarray02_01) to High(myarray02_01) do
begin
for j:=Low(myarray02_01[i]) to High(myarray02_01[i]) do//注意，這裡是針對每個第一維元素里面包含的第二維元素的循環！
begin
Memo1.Lines.Add('i= '+IntToStr(i)+ ' j= '+IntToStr(j)+' Value: '+myarray02_01[i][j]);
end;
end;
end;
procedure TForm1.Array_02_dynamicClick(Sender: TObject);
var
//myarray02_02:array of array of string;//定義動態二維數組
i,j,n:Integer;
begin
n:=0;
SetLength(myarray02_02,100);
for i:=Low(myarray02_02) to High(myarray02_02) do
begin
SetLength(myarray02_02[i],100);//給每個一維元素分配5個二維空間（即每個一維元素裡面都有5個元素）
end;
for i:=Low(myarray02_02) to High(myarray02_02) do
begin
for j:=Low(myarray02_02[i]) to High(myarray02_02[i]) do//針對每個第一維元素里面包含的第二維元素的循環
begin
Inc(n);
myarray02_02[i][j]:=IntToStr(n)+'_D'
end;
end;
Memo1.Clear;
for i:=Low(myarray02_02) to High(myarray02_02) do
begin
for j:=Low(myarray02_02[i]) to High(myarray02_02[i]) do
begin
Memo1.Lines.Add('i= '+IntToStr(i)+ ' j= '+IntToStr(j)+' Value: '+myarray02_02[i][j]);
end;
end;
{
for i:=Low(myarray02_02) to High(myarray02_02) do
begin
SetLength(myarray02_02[i],0);//先釋放二維裡的空間
end;
SetLength(myarray02_02,0);//再釋放一維的空間
} //這裡真的有必要釋放2次嗎？把這2句代碼拿出來放到按鈕里對比測試一下看下效果~~
end;
procedure TForm1.Button1Click(Sender: TObject);
var
i:Integer;
begin
//這裡為了說明有無必要釋放2次，先2次釋放一起運行一遍，然後再注釋掉第1次釋放的之後
//再運行，同時打開工作管理員，選擇‘處理程序’頁，找到當前運行的exe，對比看看
//該exe的‘記憶體(私人工作集)’的2次運行有啥差別。
{for i:=Low(myarray02_02) to High(myarray02_02) do
begin
SetLength(myarray02_02[i],0);//先釋放二維裡的空間
end;
}
SetLength(myarray02_02,0);//再釋放一維的空間
//事實證明，先釋放二維再釋放一維和直接釋放一維的效果一樣！調試時也能看到2種釋放
//方式之後數組里的值都會被清空！
end;
end.
form窗体代码：
object Form1: TForm1
Left = 417
Top = 394
Width = 511
Height = 234
Caption = 'Form1'
Color = clBtnFace
Font.Charset = DEFAULT_CHARSET
Font.Color = clWindowText
Font.Height = -11
Font.Name = 'MS Sans Serif'
Font.Style = []
OldCreateOrder = False
PixelsPerInch = 96
TextHeight = 13
object Array_01_static: TButton
Left = 3
Top = 38
Width = 117
Height = 25
Caption = 'Array_01_static'
TabOrder = 0
OnClick = Array_01_staticClick
end
object Array_01_dynamic: TButton
Left = 4
Top = 96
Width = 118
Height = 25
Caption = 'Array_01_dynamic'
TabOrder = 1
OnClick = Array_01_dynamicClick
end
object Array_02_static: TButton
Left = 376
Top = 38
Width = 103
Height = 25
Caption = 'Array_02_static'
TabOrder = 2
OnClick = Array_02_staticClick
end
object Array_02_dynamic: TButton
Left = 376
Top = 98
Width = 106
Height = 25
Caption = 'Array_02_dynamic'
TabOrder = 3
OnClick = Array_02_dynamicClick
end
object Memo1: TMemo
Left = 132
Top = 4
Width = 231
Height = 144
ImeName = '中文(?体) - 搜狗拼音?入法'
Lines.Strings = (
'Memo1')
ScrollBars = ssBoth
TabOrder = 4
end
object Button1: TButton
Left = 393
Top = 141
Width = 75
Height = 25
Caption = '釋放'
TabOrder = 5
OnClick = Button1Click
end
end