I Want to access Interfaces of Selected Project When Right Click to project after add in new item to vs 2010

I Want to access Interfaces of Selected Project When Right Click to
project after add in new item to vs 2010

I do this Code:
`public void OnConnection(object application, ext_ConnectMode
connectMode, object addInInst, ref Array custom)
{
_applicationObject = (DTE2)application;
_addInInstance = (AddIn)addInInst;
if(connectMode == ext_ConnectMode.ext_cm_UISetup)
{
object[] contextGUIDS = new object[] { };
Commands2 commands =
(Commands2)_applicationObject.Commands;
CommandBar SECommandBar =
((CommandBars)_applicationObject.CommandBars)["Context
Menus"];
CommandBarPopup SEPopUps =
(CommandBarPopup)SECommandBar.Controls["Project and
Solution Context Menus"];
CommandBarPopup oCommandBar =
(CommandBarPopup)SEPopUps.Controls["Project"];
CommandBarControl oControl = (CommandBarControl)
oCommandBar.Controls.Add(MsoControlType.msoControlButton,
System.Reflection.Missing.Value,
System.Reflection.Missing.Value, 1, true);
// Set the caption of the menuitem
oControl.Caption = "Create Documentation";
oSubMenuItemHandler =
_applicationObject.Events.get_CommandBarEvents(oControl)
as CommandBarEventsClass;
oSubMenuItemHandler.Click+=new
_dispCommandBarControlEvents_ClickEventHandler(oSubMenuItemHandler_Click);
}
protected void oSubMenuItemHandler_Click(object CommandaBarControl,ref
bool handled, ref bool cancelDefault)
{
// I Want to access object of selected project ot get its interfaces
MessageBox.Show("Test");
}`
Please I want to access selected project to get all Classes and Interfaces
or access selected class or Interface