CBrowseCtrl - Adding File/Folder-Browse Features to Your Projects Easily

Introduction

Usually, when we need to add file/folder-browse features to our projects, we have to do quite some trivia: first we must create a CEdit which will display the path name, then we need to create a CButton and handle its ON_BN_CLICKED event to launch the CFileDialog and copy the path name to the CEdit. Furthermore, if we want to make it look nice, we will have to include some icon or bitmap resources to decorate the CButton. It could cause some headache if we have multiple dialogs which all need the file/folder-browse feature on them.

I have been thinking that it would be nice if there was such a control in MFC, which integrates a CEdit and a CButton on it, handles the control events, pops up the CFileDialog and updates CEdit text automatically. And it'd be even nicer if that control has some built-in images, that is, it has its own drawing capability without requiring us to provide any image resource to it. And of course, some tooltips wouldn't hurt... Unfortunately, there's no such control in MFC, but fortunately we can always make our own.

CBrowseCtrl is made for meeting the exact needs I described in the above paragraphs. It derives from CButton, has an editbox, a browse button and a tooltip on it. It can draw some built-in images on the browse button as well, so you don't need to include any icon or bitmap resources for this control. It handles button events by itself so whenever the user clicks on the browse button, a file/folder dialog pops up.

How to Use

You need to add source files BrowseCtrl.h and BrowseCtrl.cpp to your workspace first, and include BrowseCtrl.h wherever needed. To create the control, you can either use CBrowseCtrl::Create to create one at runtime, or draw a CButton on the dialog template and bind it with a CBrowseCtrl variable.

Code Samples

Specifying Control Styles

You may access the control styles anytime to change its appearance and behavior. Multiple style flags may be combined using the "|" operator. The valid style flags are:

Flag	Effects
BC_CTL_ALLOWEDIT	Allows user to type in the editbox
BC_CTL_FOLDERSONLY	Browse for folders instead of files
BC_BTN_LEFT	Display the browse button on the left-side of the editbox
BC_BTN_FLAT	Use flat button style
BC_BTN_ICON	Use icon, no text will be displayed
BC_ICO_ARROWFOLDER	The arrow-folder icon, must be combined with BC_BTN_ICON
BC_ICO_FOLDER	The folder icon, must be combined with BC_BTN_ICON
BC_ICO_EXPLORER	The Windows Explorer icon, must be combined with BC_BTN_ICON

To set the "Windows Explorer" icon on the browse button, make the button flat, and finally, make the control "Browse for Folders" only:

DWORD dwStyle = m_wndBrowseCtrl.GetButtonStyle();

dwStyle |= BC_BTN_ICON; // Make sure to display icon instead of text

dwStyle |= BC_BTN_FLAT; // Flat button

dwStyle &= ~BC_ICO_ARROWFOLDER; // Remove other icons

dwStyle &= ~BC_ICO_FOLDER;

dwStyle |= BC_ICO_EXPLORER; // Set the explorer icon

dwStyle |= BC_CTL_FOLDERSONLY; // Browse for folders only

m_wndBrowseCtrl.SetButtonStyle(dwStyle); // Apply

I've got tired of images and want the browse button to display text, say, "Click Me!", also make it display tooltip "Click to browse your files.":

m_wndBrowseCtrl.SetButtonStyle(m_wndBrowseCtrl.GetButtonStyle() & ~BC_BTN_ICON);

m_wndBrowseCtrl.SetButtonText(_T("Click Me!"));

m_wndBrowseCtrl.SetTooltipText(_T("Click to browse your files."));

Browsing for Files and Folders

CBrowseCtrl handles the button events by itself so whenever the user clicks on the browse button, a file or folder dialog is popped up automatically. You can, of course, programmatically handle it in your code also, usually you may want to initialize the file dialog using whatever you would pass into the CFileDialog constructor. CBrowseCtrl provides a set of functions to allow doing the same initialization, you basically can just treat the control as a dialog:

m_wndBrowseCtrl.SetOpenSave(TRUE); // TRUE-"open", FALSE-"save as"

m_wndBrowseCtrl.SetDefExt(NULL); // Do not use any default extension

m_wndBrowseCtrl.SetFilter(_T("Text Files (*.txt)|*.txt|All Files (*.*)|*.*||"));

m_wndBrowseCtrl.SetFileFlags(OFN_FILEMUSTEXIST | OFN_HIDEREADONLY);

m_wndBrowseCtrl.SetPathName(_T("c:\\MyApp\\readme.txt")); // default path



if (m_wndBrowseCtrl.DoModal() == IDOK)

MessageBox(m_wndBrowseCtrl.GetPathName());

To browse for folders:

m_wndBrowseCtrl.SetButtonStyle(m_wndBrowseCtrl.GetButtonStyle()

| BC_CTL_FOLDERSONLY);

// Display an editbox on the dialog

m_wndBrowseCtrl.SetFolderFlags(BIF_EDITBOX);

m_wndBrowseCtrl.SetFolderDialogTitle(_T("Please select a folder"));

if (m_wndBrowseCtrl.DoModal() == IDOK)

MessageBox(m_wndBrowseCtrl.GetPathName());

And if the user has selected multiple files from the file dialog, you can iterate through all path names by the following code:

if (m_wndBrowseCtrl.GetSelectedCount() > 1)// Multiple files selected

{

POSITION pos = m_wndBrowseCtrl.GetStartPosition();

while (pos != NULL)

{

CString sPathName = m_wndBrowseCtrl.GetNextPathName(pos);

// Process the path name...

    }

}

Notifying the Parent Window

After the file/folder dialog is closed by the user, a notifying message is sent to the parent window. The wParam is either IDOK or IDCANCEL, the lParam is a pointer to this CBrowseCtrl object.

To make the control notify the parent window, you need to provide CBrowseCtrl a custom window message which is greater than 0. If the message you provide is 0, the message will not be sent. If you do not provide any message, no message will be sent either.

#define WM_BROWSE_NOTIFY WM_APP + 100

m_wndBrowseCtrl.SetNotifyMessageID(WM_BROWSE_NOTIFY);

// Now ready to receive the notification!

Conclusion

So that's about it. It is a nice little control to have around, I hope it could help you in some cases. Any suggestions are welcome, thanks for your time.

History

Jan 08, 2004

• Initial release.

Jan 09, 2004

• Improved drawing functions to properly handle the case in which the control client area is too small to be drawn. In debug mode, it will provide a message box to inform the developer about that issue.
• Improved the edit box so it acts better upon receiving and losing the input focus.
• Updated the source code and demo project.

Jan 10, 2004

• Fixed a problem where the edit box is not properly redrawn upon certain events. Thanks to JOHN11.
• Added method CBrowseCtrl::GetSelectedCount which returns the number of items the user has selected in the most recent file/folder dialog that was terminated by IDOK.
• Improved the mouse/focus events monitoring functions.
• Fixed a drawing glitch which could occur when the user clicks on the edges of the edit box.
• Changed the drawing-area calculating methods for performance improvement.
• Updated the source code and demo project.

Jan 14, 2004

• Updated SetPathName and GetPathName member functions.
• Altered the message sending method so the lParam is now a pointer to this CBrowseCtrl object.
• Updated the source code and demo project.

Jan 22, 2004

• Added methods to monitor whether the user has manually changed the contents of the edit box when BC_CTL_ALLOWEDIT is set. The return value of GetPathName will also be properly affected.
• The window titles of file/folder dialogs can now be accessed by calling SetDialogTitle and GetDialogTitle.
• The banner text of folder dialogs can now be accessed by calling SetDialogBanner and GetDialogBanner.
• Added method ModifyButtonStyle to allow convenient style changing.

Feb 07, 2004

• Improved drawing functions so that images/text on the browse button are partially drawn if there is not enough space.

May 22, 2004

• Updated drawing functions.
• Added functions: GetDriveLetter, GetDirectory, GetFileName, GetFileTitle, GetFileExt.

License

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