本文整理自网络，侵删。
内存管理[4]
一个使用私有堆的例子:
unit Unit1;interfaceuses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls;type TForm1 = class(TForm) Button1: TButton; procedure Button1Click(Sender: TObject); end;var Form1: TForm1;implementation{$R *.dfm}var MyHeap: THandle; {堆句柄} p: Pointer;procedure TForm1.Button1Click(Sender: TObject);var i,num: Integer; p2: Pointer; str: string;begin {建立堆} MyHeap := HeapCreate(HEAP_ZERO_MEMORY, 1024*1024*2, 0); {建立个 2M 的堆} if Myheap = 0 then Exit; {如果创建失败则退出} {从堆中分配内存} p := HeapAlloc(MyHeap, 0, 7); if p = nil then Exit; {出错退出} {获取内存块大小} num := HeapSize(MyHeap, 0, p); {给内存块的每个字节赋值} p2 := p; for i := 0 to num - 1 do begin Byte(p2^) := i + 65; p2 := Ptr(Integer(p2) + 1); end; {取值} p2 := p; str := ''; for i := 0 to num - 1 do begin str := str + Chr(Byte(p2^)); p2 := Ptr(Integer(p2) + 1); end; {显示内存块的内容与大小} ShowMessageFmt('%s,%d',[str,num]); {ABCDEFG,7} ///////////////////////////////////////////////////// {扩充内存, 只此一句不同, 下面都是重复上面的代码} p := HeapReAlloc(MyHeap, 0, p, 26); if p = nil then Exit; {出错退出} {获取内存块大小} num := HeapSize(MyHeap, 0, p); {给内存块的每个字节赋值} p2 := p; for i := 0 to num - 1 do begin Byte(p2^) := i + 65; p2 := Ptr(Integer(p2) + 1); end; {取值} p2 := p; str := ''; for i := 0 to num - 1 do begin str := str + Chr(Byte(p2^)); p2 := Ptr(Integer(p2) + 1); end; {显示内存块的内容与大小} ShowMessageFmt('%s,%d',[str,num]); {ABCDEFGHIJKLMNOPQRSTUVWXYZ,26} ///////////////////////////////////////////////////// {释放内存} HeapFree(MyHeap, 0, p); {销毁堆} HeapDestroy(MyHeap);end;end.
相关阅读 >>
更多相关阅读请进入《Delphi》频道 >>
