Delphi动态数组释放问题
<p>动态数组为什么要释放？</p><p>---------</p>
<p><img src="https://img2020.cnblogs.com/blog/811422/202109/811422-20210909141131765-581951224.png"></p>
<p> </p>
<p> </p>
<p>数组释放的三种方法：</p>
<p>Delphi属性参数和数组释放 https://www.cnblogs.com/dmqhjp/p/15078520.html</p>
<p> </p>
<p>--------------</p>
<p>Unit开始</p>
<div class="cnblogs_code">
<pre class="language-none"><code>1 unit Unit1;
2
3 interface
4
5 uses
6 Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
7 Dialogs, StdCtrls;
8
9 type
10 TForm1 = class(TForm)
11 Button1: TButton;
12 Button2: TButton;
13 Memo1: TMemo;
14 Button3: TButton;
15 Button4: TButton;
16 procedure Button1Click(Sender: TObject);
17 procedure Button2Click(Sender: TObject);
18 procedure Button3Click(Sender: TObject);
19 procedure Button4Click(Sender: TObject);
20 private
21 { Private declarations }
22 public
23 { Public declarations }
24 end;
25
26 var
27 Form1: TForm1;
28
29 implementation
30
31 var
32 GlobalArray:array of array of string;
33 {$R *.dfm}
34
35 procedure TForm1.Button1Click(Sender: TObject);
36 var
37 i,j,vCount:Integer;
38 begin
39 //初始化GlobalArray
40 SetLength(GlobalArray,5);
41 for i:=Low(GlobalArray) to High(GlobalArray) do
42 begin
43 SetLength(GlobalArray,5);
44 end;
45 //为这个GlobalArray赋值
46 vCount:=0;
47 Memo1.Lines.Add('------GlobalArray--赋值开始-------Button1-------');
48 for i:=Low(GlobalArray) to High(GlobalArray)do
49 begin
50 for j:=Low(GlobalArray) to High(GlobalArray)do
51 begin
52 Inc(vCount);
53 GlobalArray:='GlobalArray_'+inttostr(vCount);
54 Memo1.Lines.Add(GlobalArray);
55 end;
56 end;
57 Memo1.Lines.Add('------GlobalArray--赋值结束-------Button1-------');
58 end;
59
60 procedure TForm1.Button2Click(Sender: TObject);
61 var
62 i,j,vCount:Integer;
63 begin
64 //初始化GlobalArray
65 SetLength(GlobalArray,3);
66 for i:=Low(GlobalArray) to High(GlobalArray) do
67 begin
68 SetLength(GlobalArray,3);
69 end;
70
71 vCount:=0;
72 Memo1.Lines.Add('------GlobalArray--不赋值显示 开始------Button2--------');
73 for i:=Low(GlobalArray) to High(GlobalArray)do
74 begin
75 for j:=Low(GlobalArray) to High(GlobalArray)do
76 begin
77 Memo1.Lines.Add(GlobalArray);
78 end;
79 end;
80 Memo1.Lines.Add('------GlobalArray--不赋值显示 结束------Button2--------');
81
82 //为这个GlobalArray赋值
83 vCount:=0;
84 Memo1.Lines.Add('------GlobalArray--赋值开始------Button2--------');
85 for i:=Low(GlobalArray) to High(GlobalArray)do
86 begin
87 for j:=Low(GlobalArray) to High(GlobalArray)do
88 begin
89 Inc(vCount);
90 GlobalArray:='GlobalArray_Button2_'+inttostr(vCount);
91 Memo1.Lines.Add(GlobalArray);
92 end;
93 end;
94 Memo1.Lines.Add('------GlobalArray--赋值结束------Button2--------');
95 end;
96
97 procedure TForm1.Button3Click(Sender: TObject);
98 var
99 i:Integer;
100 begin
101 for i:=Low(GlobalArray) to High(GlobalArray) do
102 begin
103 GlobalArray:=nil;
104 end;
105 GlobalArray:=nil;
106 end;
107
108 procedure TForm1.Button4Click(Sender: TObject);
109 var
110 i,j,vCount:Integer;
111 begin
112 //初始化GlobalArray
113 SetLength(GlobalArray,5);
114 for i:=Low(GlobalArray) to High(GlobalArray) do
115 begin
116 SetLength(GlobalArray,5);
117 end;
118
119 vCount:=0;
120 Memo1.Lines.Add('------GlobalArray--不赋值显示 开始------Button4--------');
121 for i:=Low(GlobalArray) to High(GlobalArray)do
122 begin
123 for j:=Low(GlobalArray) to High(GlobalArray)do
124 begin
125 Memo1.Lines.Add(GlobalArray);
126 end;
127 end;
128 Memo1.Lines.Add('------GlobalArray--不赋值显示 结束------Button4--------');
129
130 //为这个GlobalArray赋值
131 vCount:=0;
132 Memo1.Lines.Add('------GlobalArray--赋值开始------Button4--------');
133 for i:=Low(GlobalArray) to High(GlobalArray)do
134 begin
135 for j:=Low(GlobalArray) to High(GlobalArray)do
136 begin
137 Inc(vCount);
138 GlobalArray:='GlobalArray_Button4_'+inttostr(vCount);
139 Memo1.Lines.Add(GlobalArray);
140 end;
141 end;
142 Memo1.Lines.Add('------GlobalArray--赋值结束------Button4--------');
143 end;
144
145 end.</code></pre>
</div>
<p> </p>
<p>Unit结束</p>
<p> </p>
<p>--Form开始</p>
<div class="cnblogs_code">
<pre class="language-none"><code> 1 object Form1: TForm1
2 Left = 626
3 Top = 279
4 Width = 594
5 Height = 675
6 Caption = 'Form1'
7 Color = clBtnFace
8 Font.Charset = DEFAULT_CHARSET
9 Font.Color = clWindowText
10 Font.Height = -11
11 Font.Name = 'MS Sans Serif'
12 Font.Style = []
13 OldCreateOrder = False
14 PixelsPerInch = 96
15 TextHeight = 13
16 object Button1: TButton
17 Left = 288
18 Top = 24
19 Width = 225
20 Height = 25
21 Caption = 'Button1_GlobalArray初始化并赋值'
22 TabOrder = 0
23 OnClick = Button1Click
24 end
25 object Button2: TButton
26 Left = 264
27 Top = 192
28 Width = 281
29 Height = 25
30 Caption = 'Button2_GlobalArray之再使用'
31 TabOrder = 1
32 OnClick = Button2Click
33 end
34 object Memo1: TMemo
35 Left = 0
36 Top = 0
37 Width = 257
38 Height = 637
39 Align = alLeft
40 ImeName = '中文(简体) - 搜狗拼音输入法'
41 ScrollBars = ssBoth
42 TabOrder = 2
43 end
44 object Button3: TButton
45 Left = 312
46 Top = 104
47 Width = 75
48 Height = 25
49 Caption = 'Button3'
50 TabOrder = 3
51 OnClick = Button3Click
52 end
53 object Button4: TButton
54 Left = 280
55 Top = 304
56 Width = 257
57 Height = 25
58 Caption = 'Button4_GlobalArray之再使用'
59 TabOrder = 4
60 OnClick = Button4Click
61 end
62 end</code></pre>
</div>
<p> </p>
<p>--Form结束</p>
<p> </p><br><br>
来源：https://www.cnblogs.com/dmqhjp/p/15246757.html
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