Message Bar items are messages with an accompanying hyperlink that, when clicked, navigates the user to a location in the navigation tree.

Adding Message Bar items

Add a message bar item with NavInsertItem.

void AddMessageBarItem(LPCWSTR text, LPCWSTR link)
{
	// First get the root of the MESSAGEBAR domain
	NAVSETITEM messageBarRootData;
	memset(&messageBarRootData, 0, sizeof(NAVSETITEM));
	if( !NavGetItem(_T("MESSAGEBAR"), &messageBarRootData) )
	{
		return;														// Failed to find MESSAGEBAR root
	}
	NavHandle messageBarRoot = messageBarRootData.hItem;
 
	// Now add a simple message bar item
	NAVSETITEM newItem;
	memset(&newItem, 0, sizeof(newItem));
	newItem.flags = NI_FLAG_MESSAGEBAR_ICONWARNING;						// The icon we want to show. NI_FLAG_MESSAGEBAR_ICONINFO, NI_FLAG_MESSAGEBAR_ICONWARNING and NI_FLAG_MESSAGEBAR_ICONSHIELD
	newItem.EventMask = NI_EVENT_MOUSE_LCLICK;							// Need click events to navigate somewhere when the link is clicked
	newItem.strLabel = L"This is a message bar message";
	newItem.strDescription = L"NAVIGATIONTREE\\ControlPanel\\Events";	// Override description field as the FQN or alias to navigate to when the link is clicked
	newItem.lParam = 0;													// Custom context data
	newItem.pInterface = &notificationInterface;						// Interface to handle messages from the message bar
	NavInsertItem(messageBarRoot, _T("MyComponentWarningEvents"), &newItem);
}

Items added in the manner shown above display the strLabel text as the message, followed by a link that says "Go There". If you click the link, the WMC navigates to the location specified in strDescription. You can provide customised hyperlink text by providing your own XAML content.

 

FlagDescription
NI_FLAG_MESSAGEBAR_ICONWARNING
NI_FLAG_MESSAGEBAR_ICONINFO
NI_FLAG_MESSAGEBAR_ICONSHIELD
The type of icon to show. Mutually exclusive.
NI_FLAG_MESSAGEBAR_NOTIFYNotify the item of the click. Without this flag the default behaviour is to go to a navigation location. Calls the NavItemNotify handler of the notification interface supplied in NavInsertItem
NI_FLAG_MESSAGEBAR_USERXAMLYou wish to supply the full XAML for the item. See below for details.

 

NI_FLAG_MESSAGEBAR_NOTIFY means call NavNotifyItem, else calls NavGotoItem. If NI_FLAG_MESSAGEBAR_NOTIFY then we notify the tag, otherwise we goto the description

 

Custom link text

The default link text is Go There but it can be customised by providing your own XAML when inserting the element. To use custom XAML you need to set the flag NI_FLAG_MESSAGEBAR_USERXAML in the NAVSETITEM structure. strLabel then becomes the custom XAML and the Hyperlink node's Tag attribute in the XAML specifies the location to navigate to. e.g.

void AddMessageBarItem(LPCWSTR text, LPCWSTR link)
{
	// First get the root of the MESSAGEBAR domain
	NAVSETITEM messageBarRootData;
	memset(&messageBarRootData, 0, sizeof(NAVSETITEM));
	if( !NavGetItem(_T("MESSAGEBAR"), &messageBarRootData) )
	{
		return;														// Failed to find MESSAGEBAR root
	}
	NavHandle messageBarRoot = messageBarRootData.hItem;
 
	NAVSETITEM newItem;
	memset(&newItem, 0, sizeof(newItem));
	newItem.flags = NI_FLAG_MESSAGEBAR_USERXAML;
	newItem.EventMask = NI_EVENT_MOUSE_LCLICK;

	std::wstring strLabel;
	FormatString(strLabel, L"<Image Source='2400'/><TextBlock Padding='3, 0, 20, 0' VerticalAlignment='Center'>This is the message: <Hyperlink Tag='MESSAGEBAR\\MyComponent'>%s</Hyperlink></TextBlock>", CResString(IDS_LABEL_THEREISANOTIFICATION).GetBuffer(0), CResString(IDS_LABEL_GOTONOTIFICATIONS).GetBuffer(0));

	ItemNew.strLabel = strLabel.c_str();
	ItemNew.strDescription = _T("{Notifications}");	   // where to go to
	ItemNew.lParam = (LPARAM)this;
	ItemNew.pInterface = &gTaskInterface;
	NavInsertItem(hMessageBar, _T("NotificationWarning"), &ItemNew);
	hWarning = ItemNew.hItem;
}