When you create your dialog-template resource with the [dialog editor](../windows/dialog-editor.md), you drag controls from a controls palette and drop them into the dialog box. This adds the specifications for that control type to the dialog-template resource. When you construct a dialog object and call its **Create** or `DoModal` member function, the framework creates a Windows control and places it in the dialog window on screen.

You might be familiar with the **public**, `protected`, and `private` C++ keywords. When looking at the MFC header files, you will find that each class may have several of each of these. For example, public member variables and functions might be under more than one **public** keyword. This is because MFC separates member variables and functions based on their use, not by the type of access allowed. MFC uses `private` sparingly; even items considered implementation details are generally protected and many times are public. Although access to the implementation details is discouraged, MFC leaves the decision to you.

To enable tooltips for a status bar control, create the `CStatusBarCtrl` object with the **SBT_TOOLTIPS** style.

- As the user interacts with the control, it will send various notification messages. You can specify a function to handle each of the messages you want to handle by adding an **ON_NOTIFY_REFLECT** macro in your control window's message map or by adding an `ON_NOTIFY` macro to your parent window's message map. See [Tree Control Notification Messages](../mfc/tree-control-notification-messages.md) later in this topic for a list of possible notifications.

A virtual list control is a list view control that has the **LVS_OWNERDATA** style. This style enables the control to support an item count up to a `DWORD` (the default item count only extends to an `int`). However, the biggest advantage provided by this style is the ability to only have a subset of data items in memory at any one time. This allows the virtual list view control to lend itself for use with large databases of information, where specific methods of accessing data are already in place.

Virtual list controls maintain very little item information. Except for the item selection and focus information, all item information is managed by the owner of the control. Information is requested by the framework via a **LVN_GETDISPINFO** notification message. To provide the requested information, the owner of the virtual list control (or the control itself) must handle this notification. This can easily be done using the Properties window (see [Mapping Messages to Functions](../mfc/reference/mapping-messages-to-functions.md)). The resultant code should look something like the following example (where `CMyDialog` owns the virtual list control object and the dialog is handling the notification):

In the handler for the **LVN_GETDISPINFO** notification message, you must check to see what type of information is being requested. The possible values are:

- `LVIF_TEXT` The `pszText` member must be filled in.

- `LVIF_IMAGE` The `iImage` member must be filled in.

- **LVIF_INDENT** The *iIndent* member must be filled in.

Because this type of list control is intended for large data sets, it is recommended that you cache requested item data to improve retrieval performance. The framework provides a cache-hinting mechanism to assist in optimizing the cache by sending an **LVN_ODCACHEHINT** notification message.

The **LVN_ODFINDITEM** notification message is sent by the virtual list control when a particular list control item needs to be found. The notification message is sent when the list view control receives quick key access or when it receives an **LVM_FINDITEM** message. Search information is sent in the form of an **LVFINDINFO** structure, which is a member of the **NMLVFINDITEM** structure. Handle this message by overriding the `OnChildNotify` function of your list control object and inside the body of the handler, check for the **LVN_ODFINDITEM** message. If found, perform the appropriate action.

1. Create a new MFC Application project with the default settings. Call it `MyProject`.

6. Insert the following code between the brackets after the `if` statement from step 5. This code creates the `CTaskDialog`.

3. Scroll to the bottom of the string table and add a new entry. Change the ID to `TEMP_LINE1`. Set the caption to **Command Line 1**.

4. Add another new entry. Change the ID to `TEMP_LINE2`. Set the caption to **Command Line 2**.

3. Insert the following code immediately before the closing bracket of the `if` statement (before the `else` block):

2. In the **New Project** dialog box, in the left pane under **Installed Templates**, expand **Visual C++** and then select **MFC**. In the middle pane, select **MFC Application**. In the **Name** box, type `MFCD2DWalkthrough`. Choose **OK**.

4. In the **Add Custom Message** dialog box, in the **Custom Windows Message** box, type `AFX_WM_DRAW2D`. In the **Message handler name** box, type `OnDraw2D`. Select the **Registered Message** option and then choose **OK**. This action adds a message handler for the `AFX_WM_DRAW2D` message to the `CMFCD2DWalkthroughView` class.