Add an IDL MFC property

The Add IDL MFC Property wizard adds a property to an Interface Definition Library (IDL) interface defined in your Microsoft Framework Class (MFC) project.

To use this wizard, you must be in an MFC Project, ActiveX project, or an ATL project that supports MFC. For example, if you have a Microsoft ActiveX control project, you can use the following procedure to add a property to an IDL interface in the solution.

Add an IDL MFC property to your interface

1. On the View menu, select Class View.

2. In the Class View pane, right-click the name of the interface to which you want to add the property.

   Note

   You can also add properties to dispinterfaces, which, unless the project is attributed, are nested within the library node.

3. From the shortcut menu, choose Add > Add Property.

4. In the Add IDL MFC property wizard, provide the information to create the property.

5. Select OK to add the property.

For MFC dispinterfaces:

• If you select Member variable as the implementation type, a method and a variable are added to the class that implements it.
• If you select Get/Set methods as the implementation type, two methods are added to the class that implements it.

User interface element list

The following section describes the Add IDL MFC Property wizard:

• Property name

  Sets the name of the property.

  For MFC dispinterfaces associated with ActiveX controls, you can supply your own name or you can select a stock property name from the predefined list. If you provide your own property name, the Stock implementation type is unavailable.

  For more information about a description of the stock properties in the list, see stock properties.

  Interface type	Property name options
  ATL dual interface, custom interface, and local custom interface	Provide a property name.
  MFC dispinterface, MFC ActiveX control dispinterface	Provide a property name or select a stock property from the list. If you select a property from the list, the appropriate value appears in the Property type box. You can change this type, depending on the Implementation type selection.

• Property type

  Sets the type of property you're adding.

  For MFC dispinterfaces, provide your own type or select from the predefined list. If you provide a stock implementation of a property, Property type is the stock type and can't be changed.

• Variable name

  Sets the name of the member variable with which the property is associated.

  By default, the variable name is m_PropertyName. You can edit this name.

  This field is only visible for MFC dispinterfaces and if you specify Member variable under Implementation type.

• Notification function

  Sets the name of the notification function called if the property changes.

  By default, the name of the notification function is OnPropertyNameChanged. You can edit this name.

  This field is only visible for MFC dispinterfaces and if you specify Member variable under Implementation type.

• Get function

  Sets the name of the function to get the property.

  By default, the name of the Get function is GetPropertyName. You can edit this name.

  If you delete the name, the function GetNotSupported is inserted into the interface dispatch map.

  This field is only visible for MFC dispinterfaces and if you specify Get/Set methods under Implementation type.

• Set function

  Sets the name of the function to set the property.

  By default, the name of the Set function is SetPropertyName. You can edit this name.

  If you delete the name, the function SetNotSupported is inserted into the interface dispatch map.

  This field is only visible for MFC dispinterfaces and if you specify Get/Set methods under Implementation type.

• Implementation type

  Specifies how to implement the property you're adding.

  Only available for MFC dispinterfaces.

  Implementation type	Description
  Stock	Specifies a default implementation for the property selected in Property name. For more information, see stock properties. If you specify Stock, then Property type, Parameter type, and Parameter name are dimmed.
  Member variable	Adds the property as a member variable. You can add custom properties or most stock properties as member variables. Provides default names under Variable name and Notification function. You can edit this name. You can't specify Member variable for the Caption, hWnd, or Text properties.
  Get/Set methods	Specifies the property is added as GetPropertyName and SetPropertyName functions by default. These names appear under Get function and Set function. You can change the default Property type, which passes a value for the Get function. You can specify parameters for the Get and Set functions.

• Default property

  Sets the property as the default for the interface.

  An interface can have only one default property.

  Once you specify the default property, this checkbox is unavailable for any other properties that you add to the interface. Only available for an MFC dispinterface.

• Parameters

  Displays the method's parameters and its types.

• +

  Adds a parameter. In Parameters, type the parameter type and name and choose OK. For example, int x

• x

  Removes the selected parameter from the Parameters list.

• Pencil icon

  Edits the selected parameter.

• id

  Sets the numerical ID that identifies the property.

  This option isn't available for properties of custom interfaces. For more information, see id in the MIDL Reference.

• helpcontext

  Specifies a context ID that lets the user view information about this property in the Help file.

  For more information, see helpcontext in the MIDL Reference.

• helpstring

  Specifies a character string that's used to describe the element to which it applies. By default, it's property Property name.

  For more information, see helpstring in the MIDL Reference.

Stock properties

If you're adding a property to an MFC dispinterface, you can choose one of the following stock properties from the Property name dropdown list:

See Also

Add Property

Add IDL Property