Dll调用问题

Question

谢谢:liang_z(千山一刀之忍者神龟)　 果然是大小写的问题,等一下给分;
不知道第二个问题如何? 在MDI环境中用调用DLL,应如何释放DLL好呢? 不然,在主程序关闭时老是出错?

Answer 1

那要看你的DLL作用范围了！
然后在onclose中FreeDll吧

Answer 2

我一般都是静态调用MDI的DLL，
所以不用Free DLL的句柄。

Answer 3

to: yuzhizhi(小志), liang_z(千山一刀之忍者神龟)
不知道你们是如何控制的能不能贴段代码出来看看.

Answer 4

unit Main;interfaceuses Windows, SysUtils, Classes, Graphics, Forms, Controls, Menus,
  StdCtrls, Dialogs, Buttons, Messages, ExtCtrls, ComCtrls, StdActns,
  ActnList, ToolWin, ImgList;type
  TMainForm = class(TForm)
    MainMenu1: TMainMenu;
    File1: TMenuItem;
    FileNewItem: TMenuItem;
    FileOpenItem: TMenuItem;
    FileCloseItem: TMenuItem;
    Window1: TMenuItem;
    Help1: TMenuItem;
    N1: TMenuItem;
    FileExitItem: TMenuItem;
    WindowCascadeItem: TMenuItem;
    WindowTileItem: TMenuItem;
    WindowArrangeItem: TMenuItem;
    HelpAboutItem: TMenuItem;
    OpenDialog: TOpenDialog;
    FileSaveItem: TMenuItem;
    FileSaveAsItem: TMenuItem;
    Edit1: TMenuItem;
    CutItem: TMenuItem;
    CopyItem: TMenuItem;
    PasteItem: TMenuItem;
    WindowMinimizeItem: TMenuItem;
    StatusBar: TStatusBar;
    ActionList1: TActionList;
    EditCut1: TEditCut;
    EditCopy1: TEditCopy;
    EditPaste1: TEditPaste;
    FileNew1: TAction;
    FileSave1: TAction;
    FileExit1: TAction;
    FileOpen1: TAction;
    FileSaveAs1: TAction;
    WindowCascade1: TWindowCascade;
    WindowTileHorizontal1: TWindowTileHorizontal;
    WindowArrangeAll1: TWindowArrange;
    WindowMinimizeAll1: TWindowMinimizeAll;
    HelpAbout1: TAction;
    FileClose1: TWindowClose;
    WindowTileVertical1: TWindowTileVertical;
    WindowTileItem2: TMenuItem;
    ToolBar2: TToolBar;
    ToolButton1: TToolButton;
    ToolButton2: TToolButton;
    ToolButton3: TToolButton;
    ToolButton4: TToolButton;
    ToolButton5: TToolButton;
    ToolButton6: TToolButton;
    ToolButton9: TToolButton;
    ToolButton7: TToolButton;
    ToolButton8: TToolButton;
    ToolButton10: TToolButton;
    ToolButton11: TToolButton;
    ImageList1: TImageList;
    procedure FileNew1Execute(Sender: TObject);
    procedure FileOpen1Execute(Sender: TObject);
    procedure HelpAbout1Execute(Sender: TObject);
    procedure FileExit1Execute(Sender: TObject);
  private
    { Private declarations }
    procedure CreateMDIChild(const Name: string);
  public
    { Public declarations }
  end;var
  MainForm: TMainForm;//在这儿定义：
procedure CreateChildForm(MainApp:THandle);stdcall; external 'ChildDll.dll';implementation{$R *.DFM}uses About;procedure TMainForm.CreateMDIChild(const Name: string);
var
  H: HWnd;
  iMy: procedure(MainApp:THandle);stdcall;
begin
  { create a new MDI child window }
  CreateChildForm(Application.Handle);
end;procedure TMainForm.FileNew1Execute(Sender: TObject);
begin
  CreateMDIChild('NONAME' + IntToStr(MDIChildCount + 1));
end;procedure TMainForm.FileOpen1Execute(Sender: TObject);
begin
  if OpenDialog.Execute then
    CreateMDIChild(OpenDialog.FileName);
end;procedure TMainForm.HelpAbout1Execute(Sender: TObject);
begin
  AboutBox.ShowModal;
end;procedure TMainForm.FileExit1Execute(Sender: TObject);
begin
  Close;
end;end.

Answer 5

library ChildDll;{ 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
  Windows,
  SysUtils,
  Classes,
  Forms,
  Child in 'Child.pas' {Form1};var
  DllApp : THandle;
{$R *.RES}procedure MyDLLProc(Reason: Integer);
begin
//  DLL is unloading. Restore the Application pointer.
  if Reason = DLL_PROCESS_DETACH then
  begin
     if DllApp<>0 then
        Application.Handle := DllApp;
  end;
end;procedure CreateChildForm(MainApp:THandle);stdcall;export;
var
  Child : TForm1;
begin
  if not DllApp<>0 then
  begin
     DllApp := Application.Handle;
     Application.Handle := MainApp;
  end;  Child := nil;
  try
    Child := TForm1.Create(Application);
    Child.Show();
  except
    Child.Free();
  end;
end;exports
  CreateChildForm;begin
  DLLProc := @MyDLLProc;
end.

Answer 6

to: liang_z(千山一刀之忍者神龟)
在关闭Dll子窗体Form1时,是不是和关闭一般的MDI子窗体一样啊?