为什么这个最普通的动态链接库调用程序在D6中运行出错?(100分)

m_y_h · 2002-11-20

程序是从一张光盘上拷下来的. 在动态链接库调用结束时有出错信息: "0x00000000"指令引用的"0x00000000"内存.该内存不能为"read". dll中的代码: 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; exe程序代码: 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;       RaiseLastOSError;   finally     FreeLibrary(LibHandle); // Unload the DLL.   end; end;

kgafly · 2002-11-20

我也遇到过同样的问题，解法如下： 不要用LoadLibrary函数来动态的加载DLL文件，而是使用直接申明调用的方法。 在implementation后直接申明： function ShowCalendar(AHandle: THandle; ACaption: String): TDateTime;external 'DLL文件名称.dll'; 在程序里就可以自己使用函数ShowCalendar了。

m_y_h · 2002-11-20

我想在D6中动态加载dll,不知该怎么做?

jsxjd · 2002-11-20

将     FreeLibrary(LibHandle); // Unload the DLL. 放在 form 的 OnDestroy 中。 声明 LibHandle 为全局变量  if not(libhandle=null) then free........;

m_y_h · 2002-11-20

jsxjd: 我刚试了一下,现在错误出现在form的ondestroy时 好像FreeLibrary(LibHandle)执行不正常.

为什么这个最普通的动态链接库调用程序在D6中运行出错?(100分)

m_y_h

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kgafly

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m_y_h

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jsxjd

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m_y_h

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