SDIAppForm是否能广播消息到它的MDIChild子窗口？ (200分)

blackbeam · 2002-01-10

我写的代码里，MDIForm无法接收由SDIAppForm通过SendMessage(HWND_BROADCAST...)广播的消息。 但是非MDIForm子窗口就可以，是不是MDIForm有什么特殊的情况？请大家指教。 （我是重载WndProc方法来处理消息的。）

yhaochuan · 2002-01-10

广播应该是广播到系统中所以程序中吧， 假如你的程序接收到一个消息广播，那么是由application的winproc去接收的 然后做相应动作，比如，如果这个消息是系统要关机，那么它会通知FORM一个个关掉 （相当于运行mainform.close） 而且application它也不会将所以的消息传给所有FORM的 如果你想在自己的运行的两个以上的程序间传播消息，除了用广播外，当application的主FORM 接收到消息外，还要再把这消息再发给每个子FORM。 这样就相当于你的MDIFORM也收到了广播。

blackbeam · 2002-01-10

我的代码如下，请大家看看，我认为是MdiChild在消息处理上和其他类型的窗口有区别，但 不知道区别在哪里，着急啊！！！ mdichild子窗口dll ///////////////////////////////////////////////////////////////////// library mdi; { 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   SysUtils,   Classes,   Windows,   Forms,   Unit1 in 'Unit1.pas' {Form1}; procedure Load(ParentApplication : TApplication; ParentForm : TForm); export; stdcall; var   DllProc : Pointer; begin   Application:=ParentApplication;   Form1:=TForm1.Create(ParentForm);   Form1.MyParentForm:=ParentForm;   Form1.MyParentApplication:=ParentApplication;   Form1.Show; end; procedure DLLUnloadProc(Reason : Integer); register; begin   if Reason = DLL_PROCESS_DETACH then Application:=DllApplication; end; {$R *.RES} exports   Load; begin   DllApplication:=Application;   DllProc:=@DLLUnloadProc; end. ///////////////////////////////////////////////////////////////////// ///////////////////////////////////////////////////////////////////// unit Unit1; interface uses   Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,   StdCtrls; const   M_A_S = 'A';   M_B_S = 'B'; type   TForm1 = class(TForm)     Button1: TButton;     Button2: TButton;     Button3: TButton;     procedure FormCreate(Sender: TObject);     procedure Button1Click(Sender: TObject);     procedure Button2Click(Sender: TObject);     procedure Button3Click(Sender: TObject);   private     { Private declarations }     M_A : WPARAM;     M_B : WPARAM;     procedure Do_M_A(var msg:TMessage); message 12345;   protected     procedure WndProc(var Message : TMessage); override;   public     { Public declarations }     MyParentForm : TForm;     MyParentApplication : TApplication;       end; var   Form1: TForm1;   DllApplication : TApplication; implementation {$R *.DFM} procedure TForm1.FormCreate(Sender: TObject); begin   M_A:=RegisterWindowMessage(M_A_S);   M_B:=RegisterWindowMessage(M_B_S); end; procedure TForm1.WndProc(var Message : TMessage); begin   if Message.Msg = M_A then    ShowMessage('received : M_A from Mdi');   if Message.Msg = M_B then    ShowMessage('received : M_B from Mdi');   inherited WndProc(Message); end; procedure TForm1.Button1Click(Sender: TObject); begin   //SendMessage(HWND_BROADCAST,M_A,0,0);   PostMessage(HWND_BROADCAST,M_A,0,0);   ShowMessage('sended : M_A'); end; procedure TForm1.Button2Click(Sender: TObject); begin   SendMessage(HWND_BROADCAST,M_B,0,0);   ShowMessage('sended : M_B'); end; procedure TForm1.Do_M_A(var msg:TMessage); begin   ShowMessage('received : 12345 from Mdi'); end; procedure TForm1.Button3Click(Sender: TObject); begin   SendMessage(HWND_BROADCAST,12345,0,0); end; end. ///////////////////////////////////////////////////////////////////// SDI框架 ///////////////////////////////////////////////////////////////////// unit Sdimain; interface uses Windows, Classes, Graphics, Forms, Controls, Menus,   Dialogs, StdCtrls, Buttons, ExtCtrls, ComCtrls, ImgList, StdActns,   ActnList, ToolWin, Messages; const   M_A_S = 'A';   M_B_S = 'B'; type   TSDIAppForm = class(TForm)     OpenDialog: TOpenDialog;     SaveDialog: TSaveDialog;     ToolBar1: TToolBar;     ToolButton9: TToolButton;     ToolButton1: TToolButton;     ToolButton2: TToolButton;     ToolButton3: TToolButton;     ToolButton4: TToolButton;     ToolButton5: TToolButton;     ToolButton6: TToolButton;     ActionList1: TActionList;     FileNew1: TAction;     FileOpen1: TAction;     FileSave1: TAction;     FileSaveAs1: TAction;     FileExit1: TAction;     EditCut1: TEditCut;     EditCopy1: TEditCopy;     EditPaste1: TEditPaste;     HelpAbout1: TAction;     StatusBar: TStatusBar;     ImageList1: TImageList;     MainMenu1: TMainMenu;     File1: TMenuItem;     FileNewItem: TMenuItem;     FileOpenItem: TMenuItem;     FileSaveItem: TMenuItem;     FileSaveAsItem: TMenuItem;     N1: TMenuItem;     FileExitItem: TMenuItem;     Edit1: TMenuItem;     CutItem: TMenuItem;     CopyItem: TMenuItem;     PasteItem: TMenuItem;     Help1: TMenuItem;     HelpAboutItem: TMenuItem;     Message1: TMenuItem;     A1: TMenuItem;     B1: TMenuItem;     Dll1: TMenuItem;     LoadMdi1: TMenuItem;     procedure FileNew1Execute(Sender: TObject);     procedure FileOpen1Execute(Sender: TObject);     procedure FileSave1Execute(Sender: TObject);     procedure FileExit1Execute(Sender: TObject);     procedure HelpAbout1Execute(Sender: TObject);     procedure FormCreate(Sender: TObject);     procedure A1Click(Sender: TObject);     procedure B1Click(Sender: TObject);     procedure LoadMdi1Click(Sender: TObject);   private     { Private declarations }     M_A : WPARAM;     M_B : WPARAM;   protected     procedure WndProc(var Message : TMessage); override;       public     { Public declarations }   end;   T_ProvaChild = procedure (ParentApplication : TApplication; ParentForm : TForm); stdcall; var   SDIAppForm: TSDIAppForm; implementation uses About; {$R *.DFM} procedure TSDIAppForm.FileNew1Execute(Sender: TObject); begin   { Do nothing } end; procedure TSDIAppForm.FileOpen1Execute(Sender: TObject); begin   OpenDialog.Execute; end; procedure TSDIAppForm.FileSave1Execute(Sender: TObject); begin   SaveDialog.Execute; end; procedure TSDIAppForm.FileExit1Execute(Sender: TObject); begin   Close; end; procedure TSDIAppForm.HelpAbout1Execute(Sender: TObject); begin   AboutBox.ShowModal; end; procedure TSDIAppForm.FormCreate(Sender: TObject); begin   M_A:=RegisterWindowMessage(M_A_S);   M_B:=RegisterWindowMessage(M_B_S); end; procedure TSDIAppForm.A1Click(Sender: TObject); begin   SendMessage(HWND_BROADCAST,M_A,0,0);   ShowMessage('sended : M_A'); end; procedure TSDIAppForm.B1Click(Sender: TObject); begin   SendMessage(HWND_BROADCAST,M_B,0,0);   ShowMessage('sended : M_B');   end; procedure TSDIAppForm.WndProc(var Message : TMessage); begin   if Message.Msg = M_A then    ShowMessage('received : M_A');   if Message.Msg = M_B then    ShowMessage('received : M_B');   inherited WndProc(Message); end; procedure TSDIAppForm.LoadMdi1Click(Sender: TObject); var   DllHandle : THandle;   ProcAddr : FarProc;   ProvaChild : T_ProvaChild; begin   DllHandle:=LoadLibrary('mdi.dll');   ProcAddr:=GetProcAddress(DllHandle,'Load');   if ProcAddr <> nil then    begin      ProvaChild:=ProcAddr;      ProvaChild(Application,SDIAppForm);    end   else   ShowMessage('调用模块失败!'); end; end. /////////////////////////////////////////////////////////////////////

blackbeam · 2002-01-10

就差两秒！ 如yhaochuan老兄所说，就是不必用： SendMessage(HWND_BROADCAST,M_A,0,0); 而使用： SendMessage(hWnd,M_A,0,0); 那我的SDI框架必须得到当前打开的MdiChild子窗口列表，然后对其一一发送消息，是这样 吗？但是我不会做，还请赐教。

yhaochuan · 2002-01-10

有个疑问，DLL用‘A’在系统注册消息得到MSG_A EXE也用‘A’在系统注册消息得到MSG＿B，那么MSG_A是否等于MSG_B呢。 照帮助看，RegisterWindowMessage会得到唯一的消息。

yhaochuan · 2002-01-10

http://www.vclxx.org/DELPHIGB/DEFAULT.HTM里面有一个范例： MDIMSG.ZIP 示范 MDI 父子窗口以使用者自订窗口消息(User Define Windows Message) 沟通的范例程序，作者:钱达智。 （http://www.vclxx.org/DELPHI/D32SAMPL/MDIMSG.ZIP） 里面有如果取得子窗口列表并发送消息的。 你看看吧，我也温故知新。

yhaochuan · 2002-01-10

取得子窗口列表代码： procedure dosomething; var   I: Integer; begin   with Form1 do     for I := MDIChildCount-1 downto 0 do       MDIChildren.Close;//有了MDIChildren.Handle，就可以SEND消息了。 end;

blackbeam · 2002-01-10

我刚刚查过，可以通过下列代码访问： for i:=1 to SDIAppForm.MDIChildCount do    begin       SendMessage(SDIAppForm.MDIChildren.Handle,M_A,0,0);       ShowMessage('sended : M_A');    end; 但是倒霉的是我的MDIChild窗口是从一个dll文件中创建的，而SDIAppForm无法对这样的 窗口进行计数。（我在SDIAppForm中调用是成功的）。

yhaochuan · 2002-01-10

能不能将SDIAPPFORM做为一个参数传入DLL，MDIFORM在CREATE的时候以 传入的参数做为父FORM（一个思路）

blackbeam · 2002-01-10

算了，可能还要想一下，先把分给老兄得了。

yhaochuan · 2002-01-10

或者调用DLL产生MDIFORM的时候，顺便返回MDIFORM的handle， mainFORM把这个HANDLE保存到数组中，有消息的时候，循环这个数组，逐个传消息。

yhaochuan · 2002-01-10

别忘了问题真正解决的时候把解决方法POST上来。

blackbeam · 2002-01-11

是否能有更好的方法？ //调用DLL模块 procedure TSDIAppForm.LoadMdi1Click(Sender: TObject); var   DllHandle : THandle;   ProcAddr : FarProc;   ProvaChild : T_ProvaChild; begin   DllHandle:=LoadLibrary('mdi.dll');   ProcAddr:=GetProcAddress(DllHandle,'Load');   if ProcAddr <> nil then    begin      ProvaChild:=ProcAddr;      hMdiChild:=ProvaChild(Application,SDIAppForm);    end   else    ShowMessage('调用模块失败!'); end; //Dll模块 function Load(ParentApplication : TApplication; ParentForm : TForm) : HWND; export; stdcall; var   DllProc : Pointer; begin   Application:=ParentApplication;   Form1:=TForm1.Create(ParentForm);   Form1.MyParentForm:=ParentForm;   Form1.MyParentApplication:=ParentApplication;   Form1.ParentWindow:=ParentForm.Handle;   Form1.Show;   result:=Form1.Handle; end;

SDIAppForm是否能广播消息到它的MDIChild子窗口？ (200分)

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