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• Context menus can provide specific commands for particular content or a selection. For example,
selected text typically provides a context menu for clipboard commands, as shown here in the
Mail app.
• Confirmations and other questions (including collecting information) that you need to display in
response to a user action should use a flyout control; see Guidelines and checklist for Flyouts.
Tapping or clicking outside the control (or pressing ESC) is the same as canceling. Here’s an
example from the SkyDrive app:
• For blocking events that are not related to a user command but that affect the whole app, use a
message dialog. A message dialog effectively disables the rest of the app until you pay attention
to it! A good example of this is a loss of network connectivity, where the user needs to be
informed that some capabilities may not be available until connectivity is restored. User consent
prompts for capabilities like geolocation, as shown below from the Maps app, is another place
you see message dialogs. Note that a message dialog is used only when the app is in the
foreground. Toast notifications, as we’ll see in Chapter 13, “Tiles, Notifications, the Lock Screen,
and Background Tasks,” apply only to background apps.
• Finally, other errors that don’t require user action can be displayed either inline (on the app
canvas) or through flyouts. See Laying out your UI: errors for full details; we’ll see some examples
later on as well.
Where the bottom app bar is concerned, it’s also important to organize your commands into sets, as
this streamlines implementation as we’ll see in the next section. For full guidance I recommend two
additional topics in the documentation: Guidelines and checklist for app bars and Commanding Design,
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