BorlandTalk.com Borland discussion newsgroups   Archives   FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in to check your private messages   Log in  Receive data between MDI child forms          BorlandTalk.com Forum Index -> C++ Builder (VCL Components Usage) View previous topic :: View next topic   Author Message Jan Guest Posted: Fri Apr 21, 2006 11:03 am    Post subject: Receive data between MDI child forms Hello, All the forms in my application are fsMDIChild. Now the problem I have is to receive data from another form. In form 1 I call Form 2 like this: FormRelatie = new TFormRelatie(Application); In this second form, the user do a search in a database and select a record. When the user clicks on OK I need to receive in Form1 of the user clicks OK or Cancel and also what he have selected. How can I share data between this forms ? Thanks, Jan Back to top Jan Guest Posted: Fri Apr 21, 2006 11:03 am    Post subject: Re: Receive data between MDI child forms Quote: There are many ways. Please confirm first that you do not use a modal form for the query. Hans. Hans, The main form is fsMDIForm and all the others are fsMDIChild. From the main menu on the main form I call Form1. So Form1 is fsMDIChild and calls FormRelatie for a query (when the user want to do a search), FormRelatie is also fsMDIChild. Jan Back to top Hans Galema Guest Posted: Fri Apr 21, 2006 11:03 am    Post subject: Re: Receive data between MDI child forms Jan wrote: Quote: All the forms in my application are fsMDIChild. Your mainform will be a fsMDIForm I think. Quote: Now the problem I have is to receive data from another form. In form 1 I call Form 2 like this: FormRelatie = new TFormRelatie(Application); Hehh.. You mean: In form1 you created FormRelatie like this: FormRelatie = new TFormRelatie(Application); What is form 1 ? The mainform or a child ? Quote: In this second form, the user do a search in a database and select a record. When the user clicks on OK I need to receive in Form1 of the user clicks OK or Cancel and also what he have selected. Is it correct that RelatieForm is non-modal ? Quote: How can I share data between this forms ? There are many ways. Please confirm first that you do not use a modal form for the query. Hans. Back to top Hans Galema Guest Posted: Fri Apr 21, 2006 11:03 am    Post subject: Re: Receive data between MDI child forms Jan wrote: Quote: The main form is fsMDIForm and all the others are fsMDIChild. Ok. Quote: From the main menu on the main form I call Form1. What do you consider 'calling a form' ? Create it ? Show it ? Quote: So Form1 is fsMDIChild and calls FormRelatie for a query (when the user want to do a search), FormRelatie is also fsMDIChild. Can you show in code how the child calls FormRelatie ? (We know already how RelatieForm is created.) But we also do not know at which moment that is done. Also we do not know what happens with FormRelatie when the user clicks the OK-button. Does it Close() ? If so, is FormRelatie deleted then ? Hans. Back to top Jan Guest Posted: Fri Apr 21, 2006 12:03 pm    Post subject: Re: Receive data between MDI child forms Hans, What I mean calling the form1 is: Form1 = new TForm1(Application); and the form becomes visible, on form1 under the search button I have: FormRelatie = new TFormRelatie(Application); and on FormRelatie under the OK button I set the public propertys lOK = true; iID = Query->FieldByName("ID")->AsInteger; Close(); In the close event of TFormRelatie: Action = caFree; In Form1 I want to read out the properties lOK and iID; I think this is not the good way to work with MDI forms ? Jan Back to top JD Guest Posted: Fri Apr 21, 2006 12:03 pm    Post subject: Re: Receive data between MDI child forms "Jan" <jan (AT) jlcsoft (DOT) com> wrote: Quote: [...] When the user clicks on OK I need to receive in Form1 of the user clicks OK or Cancel and also what he have selected. How can I share data between this forms ? There are many different ways to accomplish this. The problem for me is that you haven't provided enough information about your design. From my perspective, communication between child forms can be problematic - especially mdiChild forms because those forms are typically deleted when closed and frequently multiple instances of the same form are permitted. I would suggest using the win32 API PostMessage to send the main form a custom message to let it know that the user has done something in the other mdiChild (note that you can use the WParam and LParam to indicate a whole bunch of things). When the main form get's the message, the main form can allocate the second mdiChild (if needed) or restore it (if it's been minimized) and then pass in any information that it needs. ~ JD Back to top Hans Galema Guest Posted: Fri Apr 21, 2006 12:03 pm    Post subject: Re: Receive data between MDI child forms Jan wrote: Quote: What I mean calling the form1 is: Form1 = new TForm1(Application); As already said: that is creating a form. Quote: and on FormRelatie under the OK button I set the public propertys lOK = true; iID = Query->FieldByName("ID")->AsInteger; Close(); In the close event of TFormRelatie: Action = caFree; In Form1 I want to read out the properties lOK and iID; In this way that is impossible. I suppose you want to read them out after FormRelatie closed. But it is deleted then too. Otherwise you could place in Form1 code like: if ( FormRelatie->lOK ) { //FormRlatie->iID } Didnot you try such code already ? If you did not use Action = caFree; then it would work. Now what is left is 'when will Form1 execute that code?'. How does form1 know that FormRelatie has closed ? So a solution would be: Place a TTimer on Form1. Enabled false. In the timereventhandler place code like void __fastcall TForm1::Timer1Timer(TObject *Sender) { Timer1->Enabled = false; lOK = FormRelatie->lOK; //FormRelatie is private iID = FormRelatie->iID; delete FormRelatie; if ( lOK ) { // } } #include "Unit1.h" // Form1 declarations void __fastcall TFormRelatie::OKButtonClick(TObject *Sender) { lOK = true; iID = Query->FieldByName("ID")->AsInteger; Close(); } void __fastcall TFormRelatie::FormClose(TObject *Sender, TCloseAction &Action) { // remove Action = caFree; Form1->Timer1->Enabled = true; } Quote: I think this is not the good way to work with MDI forms ? It was much easier when FormRelatie was not fsMDIChild and you used ShowModal() for it. Hans. Back to top JD Guest Posted: Fri Apr 21, 2006 1:03 pm    Post subject: Re: Receive data between MDI child forms Hans Galema <notused (AT) notused (DOT) nl> wrote: Quote: [...] Place a TTimer on Form1. Oh Yuck. Just use SendMessage in OnClose (instead of PostMessage) and the OnClose will wait until SendMessage returns. This will keep the form and all of it's members valid long enough for the message handler to get what it needs. ~ JD Back to top Jan Guest Posted: Fri Apr 21, 2006 1:03 pm    Post subject: Re: Receive data between MDI child forms JD wrote: Quote: Hans Galema <notused (AT) notused (DOT) nl> wrote: [...] Place a TTimer on Form1. Oh Yuck. Just use SendMessage in OnClose (instead of PostMessage) and the OnClose will wait until SendMessage returns. This will keep the form and all of it's members valid long enough for the message handler to get what it needs. ~ JD JD, Thanks, I give this a try. Also, Hans, thanks for the info. Jan -- Back to top Jan Guest Posted: Fri Apr 21, 2006 2:03 pm    Post subject: Re: Receive data between MDI child forms JD wrote: Quote: Hans Galema <notused (AT) notused (DOT) nl> wrote: [...] Place a TTimer on Form1. Oh Yuck. Just use SendMessage in OnClose (instead of PostMessage) and the OnClose will wait until SendMessage returns. This will keep the form and all of it's members valid long enough for the message handler to get what it needs. ~ JD JD, Thanks, I give this a try. Also, Hans, thanks for the info. Jan -- Back to top Hans Galema Guest Posted: Fri Apr 21, 2006 3:03 pm    Post subject: Re: Receive data between MDI child forms JD wrote: Quote: Oh Yuck. Unfamilliar with this expression I'm wondering if that was accompnied with a slash on my forehead or on your own. :-) Hans. Back to top JD Guest Posted: Fri Apr 21, 2006 4:03 pm    Post subject: Re: Receive data between MDI child forms Hans Galema <notused (AT) notused (DOT) nl> wrote: Quote: Oh Yuck. Unfamilliar with this expression It's some what like opening an expensive bottle of red that got a little too warm at some point. It's just not what you've come to expect [Yuck] but if you've never had it before, you'll most likely enjoy it anyway. ;-) Quote: I'm wondering if that was accompnied with a slash on my forehead or on your own. Certainly not mine <g>. ~ JD Back to top Jan Guest Posted: Mon Apr 24, 2006 11:03 pm    Post subject: Re: Receive data between MDI child forms I have made a little testprogram and this works fine. The main form (TForm1 is fsMDIform) and Form2 is fsMDIChild. Here is the code. Greetings, Jan FORM1.H #include "Unit2.h" #define TEST_MESSAGE (WM_APP + 400) //---------------------------------------------------------------------- ----- class TForm1 : public TForm { __published: // IDE-managed Components TButton *Button1; void __fastcall Button1Click(TObject *Sender); private: // User declarations TForm2 *Form2; protected: void __fastcall ReadMessage( TMessage & Message ) ; BEGIN_MESSAGE_MAP VCL_MESSAGE_HANDLER ( TEST_MESSAGE , TMessage , LeesMessage ) END_MESSAGE_MAP ( TForm ) public: // User declarations __fastcall TForm1(TComponent* Owner); }; //---------------------------------------------------------------------- ----- extern PACKAGE TForm1 *Form1; //---------------------------------------------------------------------- ----- FORM1.CPP TForm1 *Form1; //---------------------------------------------------------------------- ----- __fastcall TForm1::TForm1(TComponent* Owner) : TForm(Owner) { } //---------------------------------------------------------------------- ----- void __fastcall TForm1::Button1Click(TObject *Sender) { Form2 = new TForm2(this); } //---------------------------------------------------------------------- ----- void __fastcall TForm1::ReadMessage( TMessage & Message ) { bool lOk; int iRet = -1; lOk = Form2->lOk; iRet = Form2->iRet; MessageDlg("Receive notification", mtInformation, TMsgDlgButtons() << mbOK, 0); } //---------------------------------------------------------------------- ---- FORM2.H //---------------------------------------------------------------------- ----- class TForm2 : public TForm { __published: // IDE-managed Components TButton *Button1; void __fastcall Button1Click(TObject *Sender); void __fastcall FormClose(TObject *Sender, TCloseAction &Action); private: // User declarations public: // User declarations bool lOk; int iRet; __fastcall TForm2(TComponent* Owner); }; //---------------------------------------------------------------------- ----- extern PACKAGE TForm2 *Form2; //---------------------------------------------------------------------- ----- FORM2.CPP TForm2 *Form2; //---------------------------------------------------------------------- ----- __fastcall TForm2::TForm2(TComponent* Owner) : TForm(Owner) { lOk = false; iRet = 0; } //---------------------------------------------------------------------- ----- void __fastcall TForm2::ButtonCloseClick(TObject *Sender) { lOk = true; //-- just for test iRet = 99; //-- just for test Close(); } //---------------------------------------------------------------------- ----- void __fastcall TForm2::FormClose(TObject *Sender, TCloseAction &Action) { TForm *oF = dynamic_cast<TForm*>(Owner); SendMessage(oF->Handle,TEST_MESSAGE,0,0); Action = caFree; } Back to top JD Guest Posted: Tue Apr 25, 2006 1:03 pm    Post subject: Re: Receive data between MDI child forms "Jan" <jan (AT) jlcsoft (DOT) com> wrote: Quote: [...] VCL_MESSAGE_HANDLER ( TEST_MESSAGE , TMessage , LeesMessage ) <cough> You missed something in the translation ;-) You also don't have it declared correctly: private: MESSAGE void __fastcall ReadMessage( TMessage & Message ) ; public: BEGIN_MESSAGE_MAP VCL_MESSAGE_HANDLER( TEST_MESSAGE, TMessage, ReadMessage ) END_MESSAGE_MAP( TForm ) Quote: void __fastcall TForm1::ReadMessage( TMessage & Message ) Then just preface that: MESSAGE void __fastcall TForm1::ReadMessage(...) Quote: void __fastcall TForm2::FormClose(TObject *Sender, TCloseAction &Action) { TForm *oF = dynamic_cast<TForm*>(Owner); SendMessage(oF->Handle,TEST_MESSAGE,0,0); You can eliminate the #include and the casting if you send the message to Application->MainForm->Handle instead. ~ JD Back to top Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First         BorlandTalk.com Forum Index -> C++ Builder (VCL Components Usage) All times are GMT Page 1 of 1   Jump to: Select a forum C++ Builder Newsgroups----------------C++ BuilderC++ Builder (ActiveX)C++ Builder (Announcements)C++ Builder (Command Line Tools)C++ Builder DatabasesC++ Builder Databases (ADO)C++ Builder Databases (Desktop)C++ Builder Databases (InterBase Express)C++ Builder Databases (Multi-Tier)C++ Builder Databases (SQL Servers)C++ Builder (Graphics)C++ Builder (IDE)C++ Builder (Internet)C++ Builder (Internet Socket)C++ Builder (Internet Web)C++ Builder (Jobs)C++ Builder (Language)C++ Builder (Language C++)C++ Builder (Compatibility with MFC)C++ Builder (Native API)C++ Builder (Non-Technical)C++ Builder (Students)C++ Builder (Third Party Tools)C++ Builder (Upgrade)C++ Builder (VCL)C++ Builder (VCL Components Usage)C++ Builder (VCL Components Development)C++ Builder (VCL Usage)C++ Builder (WinAPI)C++ Builder Installation Delphi Newsgroups----------------Delphi (General)Delphi ActiveX Controls UsageDelphi ActiveX Controls DevelopmentDelphi As400Delphi DatabasesDelphi Databases (ADO)Delphi Databases (dbExpress)Delphi Databases (Desktop)Delphi Databases (InterBase Express)Delphi Databases (Multi-Tier)Delphi Databases (SQL Servers)Delphi DeploymentDelphi GraphicsDelphi IDEDelphi InternationalizationDelphi InternetDelphi Internet Isapi-WebBrokerDelphi Internet WebSnapDelphi Internet WinsockDelphi JobsDelphi Language BASMDelphi Language ObjectPascalDelphi Model Driven Architecture (General)Delphi Model Driven Architecture (Third Party)Delphi MultimediaDelphi Native APIDelphi Non-TechnicalDelphi ObjectPascalDelphi OLE AutomationDelphi OO designDelphi OpenToolsAPIDelphi Reporting-ChartingDelphi RTLDelphi StudentsDelphi TeamSourceDelphi Thirdparty ToolsDelphi Thirdparty Tools (General)Delphi Thirdparty Tools (IntraWeb)Delphi Thirdparty Tools (RaveReports)Delphi UpgradeDelphi VCLDelphi VCL ComponentsDelphi VCL Components UsingDelphi VCL Components WritingDelphi WebServices SOAPDelphi WinAPIDelphi XMLDelphi Installationcomp.lang.pascal.delphi.components.misccomp.lang.pascal.delphi.components.usagecomp.lang.pascal.delphi.components.writingcomp.lang.pascal.delphi.databasescomp.lang.pascal.delphi.misccomp.sources.delphi JBuilder Newsgroups----------------JBuilderJBuilder AnnouncementsJBuilder Applet IssuesJBuilder As400JBuilder CompilerJBuilder CORBA/RMIJBuilder DatabasesJBuilder DB SwingJBuilder DebuggerJBuilder DeploymentJBuilder DocumentationJBuilder EnterpriseJBuilder HandheldJBuilder IDEJBuilder JavaJBuilder JavaAPIJBuilder Java LanguageJBuilder Java SwingJBuilder Java BeansJBuilder Java Beans UsageJBuilder Java Beans DevelopmentJBuilder JBCLJBuilder JDataStoreJBuilder JobsJBuilder LinuxJBuilder MacintoshJBuilder & MobileSetJBuilder MultiLingual AppsJBuilder Non-TechnicalJBuilder OpenToolsJBuilder Servlets (JSP)JBuilder StudentsJBuilder Team DevelopmentJBuilder Thirdparty ToolsJBuilder UpgradeJBuilder Installation InterBase Newsgroups----------------InterBaseInterBase Bug DiscussionInterBase GeneralInterBase IBConsoleInterBase OpenSourceInterBase ReplicationInterBase SQLInterBase ThirdpartyInterBase Installation Miscellaneous Borland Newsgroups----------------AppCenterAppServerEnteraVisiBroker  You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum Powered by phpBB © 2001, 2006 phpBB Group SEO toolkit © 2004-2006 webmedic.