In a Windows app, command elements are interactive UI elements that let users perform actions such as sending an email, deleting an item, or submitting a form. Command interfaces are composed of common command elements, the command surfaces that host them, the interactions they support, and the experiences they provide.
Provide the best command experience
The most important aspect of a command interface is what you're trying to let a user accomplish. As you plan the functionality of your app, consider the steps required to accomplish those tasks and the user experiences you want to enable. Once you've completed an initial draft of these experiences, then you can make decisions on the tools and interactions to implement them.
Here are some common command experiences:
- Sending or submitting information
- Selecting settings and choices
- Searching and filtering content
- Opening, saving, and deleting files
- Editing or creating content
Be creative with the design of your command experiences. Choose which input devices your app supports, and how your app responds to each device. By supporting the broadest range of capabilities and preferences you make your app as usable, portable, and accessible as possible (see Commanding design for Windows apps for more detail).
Choose the right command elements
Using the right elements in a command interface can make the difference between an intuitive, easy-to-use app and a difficult, confusing app. A comprehensive set of command elements are available in the Windows app. Here's a list of some of the most common UWP command elements.
Buttons trigger an immediate action. Examples include sending an email, submitting form data, or confirming an action in a dialog.
Lists present items in an interactive list or a grid. Usually used for many options or display items. Examples include drop-down list, list box, list view and grid view.
Calendar, date and time pickers
Calendar, date and time pickers enable users to view and modify date and time info, such as when creating an event or setting an alarm. Examples include calendar date picker, calendar view, date picker, time picker.
Predictive text entry
Provides suggestions as users type, such as when entering data or performing queries. Examples include AutoSuggestBox.
For a complete list, see Controls and UI elements
Place commands on the right surface
You can place command elements on a number of surfaces in your app, including the app canvas or special command containers, such as a command bar, command bar flyout, menu bar, or dialog.
Always try to let users manipulate content directly rather than through commands that act on the content, such as dragging and dropping to rearrange list items rather than up and down command buttons.
However, this might not be possible with certain input devices, or when accommodating specific user abilities and preferences. In these cases, provide as many commanding affordances as possible, and place these command elements on a command surface in your app.
Here's a list of some of the most common command surfaces.
App canvas (content area)
If a command is constantly needed for users to complete core scenarios, put it on the canvas. Because you can put commands near (or on) the objects they affect, putting commands on the canvas makes them easy and obvious to use. However, choose the commands you put on the canvas carefully. Too many commands on the app canvas take up valuable screen space and can overwhelm the user. If the command won't be frequently used, consider putting it in another command surface.
Command bars and menu bars
Command bars help organize commands and make them easy to access. Command bars can be placed at the top of the screen, at the bottom of the screen, or at both the top and bottom of the screen (a MenuBar can also be used when the functionality in your app is too complex for a command bar).
Menus and context menus
Menus and context menus save space by organizing commands and hiding them until the user needs them. Users typically access a menu or context menu by clicking a button or right-clicking a control.
The CommandBarFlyout is a type of contextual menu that combines the benefits of a command bar and a context menu into a single control. It can provide shortcuts to commonly-used actions and provide access to secondary commands that are only relevant in certain contexts, such as clipboard or custom commands.
UWP also provides a set of traditional menus and context menus; for more info, see Menus and context menus.
Provide command feedback
Command feedback communicates to users that an interaction or command was detected, how the command was interpreted and handled, and whether the command was successful or not. This helps users understand what they've done, and what they can do next. Ideally, feedback should be integrated naturally in your UI, so users don't have to be interrupted, or take additional action unless absolutely necessary.
Provide feedback only when necessary and only if it's not available elsewhere. Keep your application UI clean and uncluttered unless you are adding value.
Here are some ways to provide feedback in your app.
The content area of the CommandBar is an intuitive place to communicate status to users if they'd like to see feedback.
Flyouts are lightweight contextual popups that can be dismissed by tapping or clicking somewhere outside the flyout.
Dialog controls are modal UI overlays that provide contextual app information. In most cases, dialogs block interactions with the app window until being explicitly dismissed, and often request some kind of action from the user. Dialogs can be disruptive and should only be used in certain situations. For more info, see the When to confirm or undo actions section.
Be careful of how much your app uses confirmation dialogs; they can be very helpful when the user makes a mistake, but they are a hindrance whenever the user is trying to perform an action intentionally.
When to confirm or undo actions
No matter how well-designed your application's UI is, all users perform an action they wish they hadn't. Your app can help in these situations by requiring confirmation of an action, or by providing a way to undo recent actions.
For actions that can't be undone and have major consequences, we recommend using a confirmation dialog. Examples of such actions include:
- Overwriting a file
- Not saving a file before closing
- Confirming permanent deletion of a file or data
- Making a purchase (unless the user opts out of requiring a confirmation)
- Submitting a form, such as signing up for something
For actions that can be undone, offering a simple undo command is usually enough. Examples of such actions include:
- Deleting a file
- Deleting an email (not permanently)
- Modifying content or editing text
- Renaming a file
Optimize for specific input types
See the Interaction primer for more detail on optimizing user experiences around a specific input type or device.