CODEWITHSUNDEEP
silverlightwindows-phone-7
user609886
user609886

Reputation: 1669

WP7 - Determine where the app will go when the "back" button is pressed

I'm working on a WP7 appliation with Silverlight. When a user clicks the back button, I want to determine where they will go to. Is there a way to determine where a user will go without managing my own nav stack?

thanks!

Upvotes: 2

Views: 1119

Answers (4)

AnthonyWJones
AnthonyWJones

Reputation: 189447

To respond to the question that has actually been asked "Is there a way to determine where a user will go without managing my own nav stack?"

You could use the OnNavigatingFrom override the eventargs of which carries the Uri of the page being navigated to. I suspect this is only useful when the navigation is back to page within your app.

Upvotes: 1

Steve Wortham
Steve Wortham

Reputation: 22220

In general you'll want to build your app composed of pages (similar to a website). For example a HyperlinkButton might be used like this:

<HyperlinkButton NavigateUri="/Page2.xaml" Content="Click here to enter page 2"/>

After clicking that then pressing the back button will automatically return to the previous page. There's no extra programming involved to make this happen... it just works.

But there are some circumstances where you'll want to override the back button. The one I ran into was the dialog box. If your app creates a dialog box, then the back button should close it instead of returning to the previous page. I wrote a brief article about how to accomplish this.

And here's a complete list of rules from Microsoft's certification requirements concerning the back button:

To maintain a consistent user experience, the Back button must only be used for backwards navigation in the application.

a. Pressing the Back button from the first screen of an application must exit the application.

b. Pressing the Back button must return the application to the previous page.

c. If the current page displays a context menu or a dialog, the pressing of the Back button must close the menu or dialog and cancel the backward navigation to the previous page.

d. For games, when the Back button is pressed during gameplay, the game can choose to present a pause context menu or dialog or navigate the user to the prior menu screen. Pressing the Back button again while in a paused context menu or dialog closes the menu or dialog.

As I found out, if you don't follow those rules they won't approve your app.

Upvotes: 0

Den
Den

Reputation: 16826

You cannot override what the back button does - the rule Derek mentioned is enforced by the system and the previous page/app will always be called.

You can, however, add an action to be executed on back key press:

this.BackKeyPress += new EventHandler<System.ComponentModel.CancelEventArgs>(MainPage_BackKeyPress);

Then just use the handler:

void MainPage_BackKeyPress(object sender, System.ComponentModel.CancelEventArgs e)
{
   // Your activity goes here
}

Upvotes: 1

Derek Lakin
Derek Lakin

Reputation: 16319

The application will go back to the previous page when the user presses the Back button. If the user is at the last page in the application, then the application will exit and the user will be navigated to the previous application. To perform anything else would be inconsistent, confusing to the user, and almost certainly would fail certification.

Upvotes: 0

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