CODEWITHSUNDEEP
c#wpfxamlwindows-8windows-phone
Daniel Little
Daniel Little

Reputation: 17263

How to pass values (parameters) between XAML pages?

Similar questions have been asked before but this question strives to explore more options and the ability to pass complex objects.

The question is how to pass parameters but it really needs to be broken up into three parts..

  1. When navigating between pages in an XAML application how do you pass parameters?
  2. What is the difference between using the Uri navigation and manual navigation?
  3. How can objects (not just strings) be passed when using Uri navigation?

Example of Uri navigation 

page.NavigationService.Navigate(new Uri("/Views/Page.xaml", UriKind.Relative));

Example of manual navigation 

page.NavigationService.Navigate(new Page());

The answer to this question applies to WP7, silverlight, WPF and Windows 8.

Note: There is a difference between Silverlight and Windows8

Upvotes: 40

Views: 80178

Answers (2)

Aaron
Aaron

Reputation: 77

For those still having issues because they don't an onNavigatedTo function to override and use a frame to navigate, this is what I used.

In the page you are navigating from: lets say this page is called "StartPoint.xaml"

NameOfFrame.Navigate(new System.Uri("Destination.xaml", UriKind.RelativeOrAbsolute), ValueToBePassed);
  • The ValueToBePassed was a simple string in my case I haven't tried with an object. (by simple string i mean string code = "hello world";)

On the Destination.xaml page : Create the page load event.

  • This can be done by going to the page's property window > events > loaded > double click the field next to loaded to auto generate the function and go to it in the code-behind.

Destinations.xaml > load

private string x;

private void Page_Loaded(object sender, RoutedEventArgs e)
{
   x = StartPoint.ValueToBePassed;
   //Call functions or do other stuff while im here
   //e.g. if (x != "") { please work you damn code }
   //     else { go to sleep and forget about the worries }
}

Upvotes: 1

Daniel Little
Daniel Little

Reputation: 17263

Methods to pass parameters

1. Using the query string

You can pass parameters through the query string, using this method means have to convert your data to strings and url encode them. You should only use this to pass simple data.

Navigating page:

page.NavigationService.Navigate(new Uri("/Views/Page.xaml?parameter=test", UriKind.Relative));

Destination page:

string parameter = string.Empty;
if (NavigationContext.QueryString.TryGetValue("parameter", out parameter)) {
    this.label.Text = parameter;
}

2. Using NavigationEventArgs

Navigating page:

page.NavigationService.Navigate(new Uri("/Views/Page.xaml?parameter=test", UriKind.Relative));

// and ..

protected override void OnNavigatedFrom(NavigationEventArgs e)
{
    // NavigationEventArgs returns destination page
    Page destinationPage = e.Content as Page;
    if (destinationPage != null) {

        // Change property of destination page
        destinationPage.PublicProperty = "String or object..";
    }
}

Destination page:

// Just use the value of "PublicProperty"..

3. Using Manual navigation

Navigating page:

page.NavigationService.Navigate(new Page("passing a string to the constructor"));

Destination page:

public Page(string value) {
    // Use the value in the constructor...
}

Difference between Uri and manual navigation

I think the main difference here is the application life cycle. Pages created manually are kept in memory for navigation reasons. Read more about it here.

Passing complex objects

You can use method one or two to pass complex objects (recommended). You can also add custom properties to the Application class or store data in Application.Current.Properties.

Upvotes: 90

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