Command Model

Wizard is designed to use the WPF command model for all wizard functions, which separates the action implementation from the user interface control that executes it. This allows for multiple and disparate sources to invoke the same centralized command logic.

All of the wizard buttons are hooked up to the appropriate command. For instance, the Next button uses the NextPage.

Command List

All of these commands are available via static properties on the WizardCommands class:

NextPage and PreviousPage

These commands are used by the wizard's Next and Back buttons.

The NextPage command follows these execution steps:

• If a WizardPage.NextPage value is set on the selected page, that page is navigated to using forward progress and the command logic quits.

• Otherwise, the next enabled sequential page, if any, will be navigated to using forward progress.

The NextPage command examines the page-specific WizardPage.NextButtonEnabled property to determine whether it is enabled. If that property is null, the WizardPage.NextPage property of the selected page will be examined to see if a specified next page is available. If that property is null, a check will be made to see if there is another enabled wizard page in sequential order after the selected page.

The PreviousPage command follows these execution steps:

• If a WizardPage.PreviousPage value is set on the selected page, that page is navigated to using backward progress and the command logic quits.

• Otherwise, the previous enabled sequential page, if any, will be navigated to using backward progress.

The PreviousPage command examines the page-specific WizardPage.BackButtonEnabled property to determine whether it is enabled. If that property is null, the WizardPage.PreviousPage property of the selected page will be examined to see if a specified previous page is available. If that property is null, a check will be made to see if there is another enabled wizard page in sequential order before the selected page.

Both commands raise the appropriate selection changed events when a page change occurs.

This XAML code shows how to use the NextPage command on a Button:

<Button Command="wizard:WizardCommands.Next">Next</Button>

Finish and Cancel

These commands are used by the wizard's Finish and Cancel buttons.

The Finish command follows these execution steps:

• Raises the Wizard.PreviewFinish event.

• Raises the WizardPage.Finish event on the selected page.

• Raises the Wizard.Finish event.

• If the event was not cancelled, the DialogResult of the containing Window will attempt to be set to true, and the Window will attempt to close.

The Finish command resolves between the page-specific WizardPage.FinishButtonEnabled property and the wizard-default Wizard.FinishButtonEnabled property to determine whether it is enabled.

The Cancel command follows these execution steps:

• Raises the Wizard.PreviewCancel event.

• Raises the WizardPage.Cancel event on the selected page.

• Raises the Wizard.Cancel event.

• If the event was not cancelled, the DialogResult of the containing Window will attempt to be set to false, and the Window will attempt to close.

The Cancel command resolves between the page-specific WizardPage.CancelButtonEnabled property and the wizard-default Wizard.CancelButtonEnabled property to determine whether it is enabled.

This XAML code shows how to use the Finish command on a Button:

<Button Command="wizard:WizardCommands.Finish">Finish</Button>

Help

This command is used by the wizard's Help button.

The Help command follows these execution steps:

• Raises the Wizard.PreviewHelp event.

• Raises the WizardPage.Help event on the selected page.

• Raises the Wizard.Help event.

The Help command resolves between the page-specific WizardPage.HelpButtonEnabled property and the wizard-default Wizard.HelpButtonEnabled property to determine whether it is enabled.

This XAML code shows how to use the Help command on a Button:

<Button Command="wizard:WizardCommands.Help">Help</Button>

GoToPage and BacktrackToPage

These commands make it extremely easy to navigate directly to a specific page by using forward or backward progress.

The GoToPage and BacktrackToPage commands both use a command parameter. The command's parameter may be set to three different types of data:

• A reference to a WizardPage within the parent Wizard.

• The name of another WizardPage within the parent Wizard.

• An integer indicating the index of a WizardPage within the parent Wizard.

The GoToPage command follows these execution steps:

• If a valid command parameter has been passed that indicates a page (see above), that page is navigated to using forward progress.

The go to page command examines the supplied command parameter to determine whether it is enabled. See above for a description of the allowed command parameter values.

The BacktrackToPage command follows these execution steps:

• If a valid command parameter has been passed that indicates a page (see above), that page is navigated to using backward progress.

The BacktrackToPage command examines the supplied command parameter to determine whether it is enabled. See above for a description of the allowed command parameter values.

Both commands raise the appropriate selection changed events when a page change occurs.

This XAML code shows how to use the GoToPage command on a Hyperlink to automatically jump to a page with a Name of targetPage:

<TextBlock><Hyperlink Command="wizard:WizardCommands.GoToPage" CommandParameter="targetPage">Go to the target page</Hyperlink></TextBlock>

This XAML code shows how to use the BacktrackToPage command on a Hyperlink to automatically jump back to the first page in the wizard:

<TextBlock><Hyperlink Command="wizard:WizardCommands.BacktrackToPage" CommandParameter="0">Go to the first page</Hyperlink></TextBlock>