摘自Delphi5开发 unit DLLFrm;interfaceuses SysUtils, WinTypes, WinProcs, Messages, Classes, Graphics, Controls, Forms, Dialogs, Grids, Calendar;type TDLLForm = class(TForm) calDllCalendar: TCalendar; procedure calDllCalendarDblClick(Sender: TObject); end;{ Declare the export function } function ShowCalendar(AHandle: THandle; ACaption: String): TDateTime; StdCall;implementation {$R *.DFM}function ShowCalendar(AHandle: THandle; ACaption: String): TDateTime; var DLLForm: TDllForm; begin // Copy application handle to DLL's TApplication object Application.Handle := AHandle; DLLForm := TDLLForm.Create(Application); try DLLForm.Caption := ACaption; DLLForm.ShowModal; Result := DLLForm.calDLLCalendar.CalendarDate; // Pass the date back in Result finally DLLForm.Free; end; end;procedure TDLLForm.calDllCalendarDblClick(Sender: TObject); begin Close; end;end.
使用Dll: unit MainFfm;interfaceuses SysUtils, WinTypes, WinProcs, Messages, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls;type { First, define a procedural data type, this should reflect the procedure that is exported from the DLL. } TShowCalendar = function (AHandle: THandle; ACaption: String): TDateTime; StdCall; { Create a new exception class to reflect a failed DLL load } EDLLLoadError = class(Exception); TMainForm = class(TForm) lblDate: TLabel; btnGetCalendar: TButton; procedure btnGetCalendarClick(Sender: TObject); end;var MainForm: TMainForm;implementation{$R *.DFM}procedure TMainForm.btnGetCalendarClick(Sender: TObject); var LibHandle : THandle; ShowCalendar: TShowCalendar; begin { Attempt to load the DLL } LibHandle := LoadLibrary('CALENDARLIB.DLL'); try { If the load failed, LibHandle will be zero. If this occurs, raise an exception. } if LibHandle = 0 then raise EDLLLoadError.Create('Unable to Load DLL'); { If the code makes it here, the DLL loaded successfully, now obtain the link to the DLL's exported function so that it can be called. } @ShowCalendar := GetProcAddress(LibHandle, 'ShowCalendar'); { If the function is imported successfully, then set lblDate.Caption to reflect the returned date from the function. Otherwise, show the return raise an exception. } if not (@ShowCalendar = nil) then lblDate.Caption := DateToStr(ShowCalendar(Application.Handle, Caption)) else RaiseLastWin32Error; finally FreeLibrary(LibHandle); // Unload the DLL. end; end;end.
unit DLLFrm;interfaceuses
SysUtils, WinTypes, WinProcs, Messages, Classes, Graphics, Controls,
Forms, Dialogs, Grids, Calendar;type TDLLForm = class(TForm)
calDllCalendar: TCalendar;
procedure calDllCalendarDblClick(Sender: TObject);
end;{ Declare the export function }
function ShowCalendar(AHandle: THandle; ACaption: String): TDateTime; StdCall;implementation
{$R *.DFM}function ShowCalendar(AHandle: THandle; ACaption: String): TDateTime;
var
DLLForm: TDllForm;
begin
// Copy application handle to DLL's TApplication object
Application.Handle := AHandle;
DLLForm := TDLLForm.Create(Application);
try
DLLForm.Caption := ACaption;
DLLForm.ShowModal;
Result := DLLForm.calDLLCalendar.CalendarDate; // Pass the date back in Result
finally
DLLForm.Free;
end;
end;procedure TDLLForm.calDllCalendarDblClick(Sender: TObject);
begin
Close;
end;end.
SysUtils, WinTypes, WinProcs, Messages, Classes, Graphics, Controls,
Forms, Dialogs, StdCtrls;type
{ First, define a procedural data type, this should reflect the
procedure that is exported from the DLL. }
TShowCalendar = function (AHandle: THandle; ACaption: String): TDateTime; StdCall; { Create a new exception class to reflect a failed DLL load }
EDLLLoadError = class(Exception); TMainForm = class(TForm)
lblDate: TLabel;
btnGetCalendar: TButton;
procedure btnGetCalendarClick(Sender: TObject);
end;var
MainForm: TMainForm;implementation{$R *.DFM}procedure TMainForm.btnGetCalendarClick(Sender: TObject);
var
LibHandle : THandle;
ShowCalendar: TShowCalendar;
begin { Attempt to load the DLL }
LibHandle := LoadLibrary('CALENDARLIB.DLL');
try
{ If the load failed, LibHandle will be zero.
If this occurs, raise an exception. }
if LibHandle = 0 then
raise EDLLLoadError.Create('Unable to Load DLL');
{ If the code makes it here, the DLL loaded successfully, now obtain
the link to the DLL's exported function so that it can be called. }
@ShowCalendar := GetProcAddress(LibHandle, 'ShowCalendar');
{ If the function is imported successfully, then set lblDate.Caption to reflect
the returned date from the function. Otherwise, show the return raise
an exception. }
if not (@ShowCalendar = nil) then
lblDate.Caption := DateToStr(ShowCalendar(Application.Handle, Caption))
else
RaiseLastWin32Error;
finally
FreeLibrary(LibHandle); // Unload the DLL.
end;
end;end.