I am following the tutorial here on Master-Detail Page
One question I am having:
Part of the solution calls for an item class as follows:
public class MasterPageItem { public string Title { get; set; } public string IconSource { get; set; } public Type TargetType { get; set; } } And in the Xaml file, you call it as this:
<ListView.ItemsSource> <x:Array Type="{x:Type local:MasterPageItem}"> <local:MasterPageItem Title="Radio" IconSource="hamburger.png" TargetType="{x:Type local:RadioPage}" /> <local:MasterPageItem Title="Item 1" TargetType="{x:Type temp:ContactsPage}" /> <local:MasterPageItem Title="Item 2" TargetType="{x:Type temp:TodoListPage}" /> <local:MasterPageItem Title="Item 3" TargetType="{x:Type temp:ReminderPage}" /> <local:MasterPageItem Title="File 4" TargetType="{}Foodaddy" /> </x:Array> </ListView.ItemsSource> What I want to do is for "File 4", rather than creating a view, I would rather send in a string, (or better an Enum), so I can call different functions. Example: Open a webpage, log out, etc. How do I modify TargetType?
1 Answers
Answers 1
If you notice in this piece of code you will see that the OnItemSelected method is handling the event and expecting for a MasterPageItem:
void OnItemSelected (object sender, SelectedItemChangedEventArgs e) { var item = e.SelectedItem as MasterPageItem; if (item != null) { Detail = new NavigationPage ((Page)Activator.CreateInstance (item.TargetType)); masterPage.ListView.SelectedItem = null; IsPresented = false; } } It is doing the navigation directly through the event handler (it's not the MVVM way to do that).
I guess @Jason's advice fits for you. Here's a way to achieve that:
You can create your own model to replace the MasterPageItem and handle its properties in a MasterDetailMenuViewModel, for example, and modify the handling to something more accurate for your need.
See the example below:
Create an amazing model to your menu items
public class AmazingMenuItem { public string ItemName { get; set; } public string ItemIconSource { get; set; } public EnumAction ActionType { get; set; } public object ActionParameter { get; set; } } public enum EnumAction { OpenPage = 0, ShowMessage = 1, PopToRoot = 2 /* ... and so on */ } Handle it in the view model*
public class MenuViewModel : SomeINotifyPropertyChangedImplementation { public Command ItemSelectedCommand { get; } /* Other properties */ public MenuViewModel() { ItemSelectedCommand = new Command<AmazingMenuItem>(ExecuteItemSelected); } private void ExecuteItemSelected(AmazingMenuItem item) { if(item != null) { switch(item.ActionType) { case EnumAction.OpenPage: var detail = (App.Current.MainPage as MasterDetailPage).Detail; if(detail is NavigationPage) detail.PushAsync((Page)Activator.CreateInstance(item.ActionParameter.GetType())); else (App.Current.MainPage as MasterDetailPage).Detail = new NavigationPage((Page)Activator.CreateInstance(item.ActionParameter.GetType())); break; case EnumAction.ShowMessage: App.Current.MainPage.DisplayAlert(item.ActionParameter.ToString(), "Ok", "Cancel"); break; case EnumAction.PopToRoot: (App.Current.MainPage as MasterDetailPage)?.Detail.PopToRootAsync(); break; } } } } * - Supposing you have made the bindings correctly
It's not a complete implementation, but I hope you've figured out a general idea of it.
Let me know if I can help you to get thru this (and sorry for any English mistake, it's not a native here).
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