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Delphi ShareMem在dll中使用
dll項目
library Project2;
{ Important note about DLL memory management: ShareMem must be the
first unit in your library's USES clause AND your project's (select
Project-View Source) USES clause if your DLL exports any procedures or
functions that pass strings as parameters or function results. This
applies to all strings passed to and from your DLL--even those that
are nested in records and classes. ShareMem is the interface unit to
the BORLNDMM.DLL shared memory manager, which must be deployed along
with your DLL. To avoid using BORLNDMM.DLL, pass string information
using PChar or ShortString parameters. }
uses
System.ShareMem,
System.SysUtils,
System.Classes,
Winapi.Windows;
//簡繁體裝換函數
function Cn2Big(CnStr: string): string; stdcall ;
var
Len: Integer;
begin
Len := Length(CnStr);
SetLength(Result, Len);
LCMapString(GetUserDefaultLCID, LCMAP_TRADITIONAL_CHINESE, PChar(CnStr), Len, PChar(Result), Len);
end;
function Big2Cn(bigStr: string): string; stdcall ;
var
Len: Integer;
begin
Len := Length(bigStr);
SetLength(Result, Len);
LCMapString(GetUserDefaultLCID, LCMAP_SIMPLIFIED_CHINESE, PChar(bigStr), Len, PChar(Result), Len);
end;
{$R *.res}
exports
Cn2Big,
Big2Cn;
begin
end.
在項目中第一種調用方式：
type
TForm4 = class(TForm)
Button1: TButton;
edt1: TEdit;
edt2: TEdit;
Button2: TButton;
procedure Button1Click(Sender: TObject);
procedure Button2Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Form4: TForm4;
function Cn2Big(CnStr: string): string; stdcall ; external 'Project2.dll';
implementation
{$R *.dfm}
procedure TForm4.Button1Click(Sender: TObject);
begin
edt2.Text := Cn2Big(edt1.Text);
end;
這種調用方式在dll和項目中都不用shareMem，不爆異常。
第二種調用方式（動態加載dll）：
procedure TForm4.Button2Click(Sender: TObject);
type
TAddc= function(const input: string): string; stdcall;
var
hh: THandle;
addc: TAddc;
begin
hh:= LoadLibrary('Project2.dll');
try
if hh<>0 then
@addc:= GetProcAddress(hh, PChar('Cn2Big'));
if not (@addc = nil) then
begin
edt2.Text := addc(edt1.Text);
end;
finally
FreeLibrary(hh);
end;
end;
在dll和項目中都不用shareMem，報異常。
在dll和項目中都用shareMem，不拋異常。
最後更新：2017-05-07 08:00:59