Using Custom Controls in a Dialog Bar

• Download Visual Studio 6 demo project - 37.4 KB
• Download Visual Studio 2005 demo project - 104.7 KB

Visual Studio 2005 Update

Please note that I have added a downloadable demo project for Visual Studio 2005 users. Everything in the original article applies to Visual Studio 2005 usage as well, except for the bit about using ClassWizard to create your class/object associations. I'm assuming that if you are using Visual Studio 2005, you already know how to define associations, add event handlers, etc. So, just ignore the ClassWizard comments. The important thing is that if you derive your own class, you must make certain that the resource ID of your dialog bar matches the resource ID defined in the class header. If you use the derived classes that I have provided, then you simply need to name your dialog bar resource in the resource editor IDD_DIALOGBAR and you will be fine. Look over the demo and if you still have difficulty getting it implemented, drop me a line.

Introduction

I've seen a lot of posts lately in forums and article comments from readers wanting to know how to use owner-drawn or custom controls in a dialog bar. Even though this information is available in various articles from Microsoft, I decided to post this article as a sort of tutorial bringing all the information together into one article.... and of course, providing working examples to look at.

In order to achieve this, you have to base your dialog bar on a class derived from CDialogBar. Since AppWizard does not support this operation, you have to derive the class from CDialog and then manually convert it to a CDialogBar class. Since the Microsoft article gives you step-by-step instructions, I'm not going to duplicate their work. I'll just point you to that article:

HOWTO: How to Initialize Child Controls in a Derived CDialogBar.

There is also a companion article:

INFO: Using CBitmapButton in CDialogBar and CFormView.

The derived classes in this example were created following the instructions from this article, primarily.

Using the Sample Classes

To use the example classes in your app, simply follow these steps. I'm assuming that you are using Visual Studio, in my case, 6.

First, from the Visual Studio main menu, click INSERT/RESOURCE and then expand DIALOG. Click IDD_DIALOGBAR and click NEW. You now have a new dialog bar resource added to your project. By default, the ID of this resource is IDD_DIALOGBAR. Leave that as it is; if you change the ID, then you must change the ID in the derived class header as well. Now add the MyDlgBar.h and MyDlgBar.cpp files from the DERIVED CLASSES folder of the sample project to your project.

At this point, you will want to link your dialog bar to your derived class. Go to your project folder and delete (or rename) the *.clw file. Then select your dialog bar in the resource editor and press CTRL_W. ClassWizard will prompt to rebuild the class wizard database. Make sure the MyDlgBar.h and MyDlgBar.cpp files are in the list and let it rebuild. It will then prompt you to add a new class or select an existing class for your dialog bar resource. Choose SELECT EXISTING CLASS and then select the CMyDlgBar class. Click OK. Now at the top of your MainFrm.h file, just above the class declaration, add the line shown below:

 . . . . . . . . . . . . 
#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000


#include "MyDlgBar.h"  <--- ADD THIS LINE

class CMainFrame : public CFrameWnd
{
 . . . . . . . . . . . . . . .

Then, inside the class declaration of your MainFrm.h file, create an instance of the dialog bar like this:

 . . . . . . . . . . . . . . . 
// Implementation

public:
        virtual ~CMainFrame();
#ifdef _DEBUG
        virtual void AssertValid() const;
        virtual void Dump(CDumpContext& dc) const;
#endif

protected:  // control bar embedded members

        CMyDlgBar m_myDlgBar;   <----- ADD THIS LINE
        CStatusBar  m_wndStatusBar;
        CToolBar    m_wndToolBar;
 . . . . . . . . . . . . . . .

Finally, to the OnCreate() function of your MainFrm.cpp file, add the following code:

           if (!m_myDlgBar.Create(this, IDD_DIALOGBAR,
                        CBRS_TOP | CBRS_GRIPPER |CBRS_TOOLTIPS | 
                        CBRS_FLYBY | CBRS_HIDE_INPLACE,
                        IDD_VIEW_DIALOGBAR))
                {
                        TRACE0("Failed to create dialog bar m_wndDlgBar\n");
                        return -1;              // fail to create

                }

                m_myDlgBar.EnableDocking(CBRS_ALIGN_TOP | CBRS_ALIGN_BOTTOM);
                EnableDocking(CBRS_ALIGN_ANY);
                DockControlBar(&m_myDlgBar);

You can modify this if you like. This creates a standard dockable dialog bar with a gripper, so that it can be undocked or moved. By default, it is created docked at the top of the app. Note IDD_VIEW_DIALOGBAR in the Create function. This is used if you want to add a menu option in the View menu to toggle hide/show of the dialog bar, as is normally done with the toolbar and status bar. Adding this function is easy. Just create a new menu item on the View menu in your resource editor. Give it an ID of IDD_VIEW_DIALOGBAR and whatever caption you wish, like &Dialog Bar. Then add the following two lines of code to the AFX_MESSAGE_MAP section of your MainFrm.cpp file, like this:

BEGIN_MESSAGE_MAP(CMainFrame, CFrameWnd)
 //{{AFX_MSG_MAP(CMainFrame)

 ON_WM_CREATE()
 // AND THE LINE BELOW

 ON_COMMAND_EX(IDD_VIEW_DIALOGBAR, OnBarCheck)  
 // AND THE LINE BELOW

 ON_UPDATE_COMMAND_UI(IDD_VIEW_DIALOGBAR, OnUpdateControlBarMenu)
 //}}AFX_MSG_MAP

END_MESSAGE_MAP()

Now you can compile and run. You will have a working dialog bar, except that you have nothing on it. So let's add an owner-drawn CBitmapButton for fun.

Adding an Owner-Drawn CBitmapButton

Just add a button to the dialog bar as normal. In Properties, check caption Owner-drawn. Give it an ID of IDC_BUTTON_BITMAP and a caption of BUTTON. This is the important part here because the AutoLoad() function reads the caption to determine what bitmaps to load. Now create four bitmaps and add/import to your project one for each state: button-up, button-down, button-focus and button-disabled. Only button-up and button-down are required; the other two are optional. Once you have added/imported these, change their IDs to the following (Important: include the quotation marks): "BUTTONU", "BUTTOND", "BUTTONF" and "BUTTONX".

Now in the ClassView tab, right-click on CMyDlgBar and choose ADD MEMBER VARIABLE. Type CBitmapButton for Variable type and m_bmButton for Variable name; make it Protected. In the MyDlgBar.cpp file in the Create() function, after the call to base class, add this code:

   if(bReturn)
                m_bmButton.AutoLoad(IDC_BUTTON_BITMAP, this);

Again, if you gave your button a different ID, you will need to change the ID here. That's it... now you have an owner-drawn CBitmapButton. The only thing left is to add a message handler for the button.

Adding the Message Handler

Just like any dialog bar, the messages must be handled in either the MainFrame, Document or View class. We will handle this one in the View class. You must add your message handlers manually. In your View class header file, add a function declaration in the message map section, like this:

// Generated message map functions

protected:
        //{{AFX_MSG(CDerivedDBView)

        afx_msg void OnButtonBitmap();   <----  ADD THIS LINE
        //}}AFX_MSG

        DECLARE_MESSAGE_MAP()
};

Then in the message map of your View class *.cpp file, edit the code as follows:

BEGIN_MESSAGE_MAP(CDerivedDBView, CFormView)
        //{{AFX_MSG_MAP(CDerivedDBView)

        //ADD THE LINE BELOW

        ON_BN_CLICKED(IDC_BUTTON_BITMAP, OnButtonBitmap)  
        //}}AFX_MSG_MAP

END_MESSAGE_MAP()

Now you add your function implementation to the bottom of your View class *.cpp file:

void CDerivedDBView::OnButtonBitmap()
{
        CString msg = "You Clicked a CBitmapButton on a Dialog Bar       \n";
        msg += "in a CDialogBar derived class!                ";
        AfxMessageBox(msg);
}

One last thing: at the top of your View class *.cpp file, add the line:

#include "MyDlgBar.h"

That's all there is to it. Compile, run and voila!, you have a working CBitmapButton in your dialog bar. This will also work with any custom control. You can add an ActiveX control if you want. For any control that you add that needs to be initialized, subclassed, owner-drawn or whatever, just do the initialization from the Create() override function in MyDlgBar.cpp, after the call to the base class.

Example: The Subclassed Button Control

The demo project includes a subclassed button control in the dialog bar. Chris Maunder has an excellent article on subclassing controls. You can see his article for instructions on deriving your class. To subclass a button in the dialog bar, use his instructions for subclassing existing items. Look at the MyDlgBar.h and MyDlgBar.cpp files in the sample project to see how this is implemented. To use the sample class files, just add NewButton.h and NewButton.cpp to your project.

Now drag a button onto your dialog bar and give it an ID of IDC_DBSUB_BUTTON. Then simply add an include for NewButton.h in the MyDlgBar.h file and add a member variable of type CNewButton (i.e. CNewButton m_subButton). Then, in the Create() function of MyDlgBar.cpp (right above or below the initialization code for your CBitmapButton), add the line:

m_subButton.SubclassDlgItem(IDC_DBSUB_BUTTON, this);

Since you have more than one instruction, be sure to place brackets around your instructions under the if() statement. Also note that we do not have to specify the button as owner-drawn in the resource editor. This is because we set up our derived class (as per Chris's instructions) to force all subclassed items to be owner-drawn. That's it. Use your imagination and you can work similar customizations with any control in a dialog bar.

History

• 12/30/04 - Added subclassed button control.
• 01/07/05 - Fixed ZIP archive compatibility issue.
• 12/07/06 - DerivedDlgBar_demo.zip is an updated demo project which fixes an issue with the ClassWizard adding subclassed control variables to the DDX Data Exchange method. DDX causes a subclass call redundancy in certain situations and ASSERTs in debug compilations. If you use the class wizard to create your subclassed control variables and get WinCore.cpp ASSERTIONs, you will need to manually remove the entries from the DDX Data map in the parent *.cpp file. In this demo, the issue arises in connection with the CBitmapButton and the AutoLoad() method.
• 11/07/07 - Uploaded Visual Studio 2005 demo project