在页面之间传递数据

Question

I'm sorry if this sounds like a completely stupid question but it really has me stumped!!

So application is made up of numerous pages that navigate from one to the other allowing users to manipulate data. On the first page (PivotPage) the data is loading into a List that is defined in a class (bay9). All this works well and I'm easily able to bind the data and manipulate it when its just on the one page. The issue is that i want the user to be able to manipulate or search against this 'list' from any other page.

What i have is the basic class;

class bay9
{
    public override string ToString()
    {
        return "Name: " + SetZone + "   ID: " + SetThermocouple;
    }



    public string setzone;

    public string SetZone
    {
        get { return setzone; }
        set { setzone = value; }
    }

    public string setthermocouple;

    public string SetThermocouple
    {
        get { return setthermocouple; }
        set { setthermocouple = value; }
    }


    public string setdata;

    public string SetData
    {
        get { return setdata; }
        set { setdata = value; }
    }

}

The basic page that the data is entered in;

public sealed partial class PivotPage : Page
{
    private NavigationHelper navigationHelper;
    private ObservableDictionary defaultViewModel = new ObservableDictionary();

    public PivotPage()
    {
        this.InitializeComponent();

        this.navigationHelper = new NavigationHelper(this);
        this.navigationHelper.LoadState += this.NavigationHelper_LoadState;
        this.navigationHelper.SaveState += this.NavigationHelper_SaveState;

        Bay9 = new List<bay9>();


        AddBay9();
    }

    List<bay9> Bay9;
    public void AddBay9()
    {

        Bay9.Add(new bay9 { SetZone = "ZONE1C" });
        Bay9.Add(new bay9 { SetZone = "ZONE1A" });
        Bay9.Add(new bay9 { SetZone = "ZONE1R" });


        cvs9.Source = Bay9;
    }
}

and a page where i want to access the data that was inputted in the previous page but cant seem to do it?

public sealed partial class RecorderPage : Page
{
    private NavigationHelper navigationHelper;
    private ObservableDictionary defaultViewModel = new ObservableDictionary();

    public RecorderPage()
    {
        this.InitializeComponent();

        this.navigationHelper = new NavigationHelper(this);
        this.navigationHelper.LoadState += this.NavigationHelper_LoadState;
        this.navigationHelper.SaveState += this.NavigationHelper_SaveState;

        Bay9 = new List<bay9>();

        LoadThermocouples();
    }

    List<bay9> Bay9;



    private void NextPageButton(object sender, RoutedEventArgs e)
    {

        this.Frame.Navigate(typeof(MainPage));

    }





    void LoadThermocouples()
    {

        int i = 0;

        foreach (bay9 aPart in Bay9)
        {


            var textBlock = new TextBlock { Text = "header ", FontSize = 55 };

            var textBox = new TextBox { Name = i.ToString(), };

            ThermocoupleStackPanel.Children.Add(textBlock);

            ThermocoupleStackPanel.Children.Add(textBox);

            i++;
        }
    }
}

I believe the issue is with declaring Bay9 = new List<bay9>(); again but don.t know how else i need to do it. with it how it is now the list is empty.

Please couple you help me out on how to access this List from this page :)

Many Thanks

Answer 1

I think the typical way of dealing with this is storing Bay9 in a ViewModel class that is accessible from everywhere in the app. See this Stack Overflow question and this article .

In my own apps, I've used the technique in the linked Stack Overflow question - making it a static property on the App class, and that's worked fine for me.

Answer 2

Try changing class bay9 to public static class bay9 . That way it will become accessible from everywhere in the app.

Answer 3

Your best bet is to take a look at the design pattern that Microsoft recommends for developing Windows Phone applications called MVVM (model-view-viewmodel) which will allow you to create better binding with data across your application.

Here is a link to a tutorial provided through the MSDN: Implementing the Model-View-ViewModel pattern for Windows Phone 8