The first time for MVVM and I got a error. So I did not know where is error

Question

App.cs {

#if DEBUG
            if (System.Diagnostics.Debugger.IsAttached)
            {
                this.DebugSettings.EnableFrameRateCounter = true;
            }
#endif

            Frame rootFrame = Window.Current.Content as Frame;

            // Do not repeat app initialization when the Window already has content,
            // just ensure that the window is active
            if (rootFrame == null)
            {
                // Create a Frame to act as the navigation context and navigate to the first page

                rootFrame = new Frame();
                var viewModel = new MainWindowModel();
                MainPage main = new MainPage();
                main.DataContext = viewModel;

                // TODO: change this value to a cache size that is appropriate for your application
                rootFrame.CacheSize = 1;

                if (e.PreviousExecutionState == ApplicationExecutionState.Terminated)
                {
                    // TODO: Load state from previously suspended application
                }

                // Place the frame in the current Window
                Window.Current.Content = rootFrame;
            }

DataAccess.cs

{
        readonly List<Menu> _menu;

        public MenuRespository()
        {
            if(_menu==null)
            {
                _menu = new List<Menu>();
            }
            _menu.Add(Menu.CreateMenu("/Photos/Gas-50.png", "t"));
            _menu.Add(Menu.CreateMenu("/Photos/Gas-50.png", "t"));
            _menu.Add(Menu.CreateMenu("/Photos/Gas-50.png", "t"));
            _menu.Add(Menu.CreateMenu("/Photos/Gas-50.png", "t"));
            _menu.Add(Menu.CreateMenu("/Photos/Gas-50.png", "t"));
            _menu.Add(Menu.CreateMenu("/Photos/Gas-50.png", "t"));
            _menu.Add(Menu.CreateMenu("/Photos/Gas-50.png", "t"));
        }
        public List<Menu> GetMenu()
        {
            return new List<Menu>(_menu);
        }
    }

Menu.cs

public class Menu
    {
        public static Menu CreateMenu(string iconthumb, string text)
        {
            return new Menu { IconThumb = iconthumb, Text = text };
        }
        public string IconThumb { get; set; }
        public string Text { get; set; }
    }

MainWindowsModel
 public class MainWindowModel :ViewModelBase
    {
        readonly MenuRespository _menuRepository;
        ObservableCollection<ViewModelBase> _viewModels;
        public MainWindowModel()
        {
            _menuRepository = new MenuRespository();
            //create an instance of our viewmodel add it to our collection
            MenuListViewModel viewModel = new MenuListViewModel(_menuRepository);
            this.ViewModels.Add(viewModel);
        }
        public ObservableCollection<ViewModelBase> ViewModels
        {
            get
            {
                if(_viewModels==null)
                {
                    _viewModels = new ObservableCollection<ViewModelBase>();

                }
                return _viewModels;
            }
        }
    }

ViewBase

 public abstract class ViewModelBase :INotifyPropertyChanged, IDisposable
    {
        protected ViewModelBase()
        {

        }
        public event PropertyChangedEventHandler PropertyChanged;

        protected virtual void OnPropertyChanged(string propertyName)
        {
            PropertyChangedEventHandler hander = this.PropertyChanged;
            if(hander!=null)
            {
                var e = new PropertyChangedEventArgs(propertyName);
                hander(this, e);
            }
        }

        public void Dispose()
        {
            this.Dispose();
        }

        protected virtual void OnDispose()
        {

        }
    }

 class MenuListViewModel :ViewModelBase
    {
        readonly MenuRespository _menuRepository;
        public ObservableCollection<Model.Menu> AllMenu
        {
            get;
            private set;
        }

        public MenuListViewModel(MenuRespository menuRepository)
        {
            if(menuRepository==null)
            {
                throw new ArgumentException("menuRepository");
            }
            _menuRepository = menuRepository;
            this.AllMenu = new ObservableCollection<Model.Menu>(_menuRepository.GetMenu());
        }

        protected override void OnDispose()
        {
            //base.OnDispose();
            this.AllMenu.Clear();
        }
    }

MenuListBox.xaml into View(show off "Severity Code Description Project File Line Error CS0263 Partial declarations of 'MenuListBox' must not specify different base classes

MixNokia.Windows

"

<UserControl
    x:Class="MixNokia.View.MenuListBox"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:MixNokia.View"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d">

    <StackPanel>
        <ListBox ItemsSource="{Binding AllMenu}">
            <ListBox.ItemTemplate>
                <DataTemplate>
                    <StackPanel Orientation="Horizontal">
                        <Image Source="{Binding IconThumb}"  Width="40" Height="40" VerticalAlignment="Center" HorizontalAlignment="Left"></Image>
                        <TextBlock Text="{Binding Text}" FontSize="15" Foreground="#CCCCCC" VerticalAlignment="Center" HorizontalAlignment="Center"></TextBlock>
                    </StackPanel>
                </DataTemplate>
            </ListBox.ItemTemplate>
        </ListBox>
    </StackPanel>
</UserControl>

The final

<Page
    x:Class="MixNokia.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:MixNokia"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:vm="clr-namespace:MixNokia.ViewModel"
    xmlns:v="clr-namespace:MixNokia.View"
    mc:Ignorable="d">
    <Page.Resources>

        <DataTemplateSelector x:Key="vm:MainWindowViewModel"></DataTemplateSelector>
    </Page.Resources>

<ListBox x:Name="lstMainMenu"
 SelectionChanged="lstMainMenu_SelectionChanged"
 Background="Transparent"
 ItemsSource="{Binding ViewModel}">
I'm developing on universal.

possible duplicate of [Partial declarations must not specify different base classes](http://stackoverflow.com/questions/8800872/partial-declarations-must-not-specify-different-base-classes) — Sheepy, Apr 09 '15 at 02:26
What a mess. We don't want a dump of your entire poorly formatted codebase. We want the full details of the error message. Sheepy's link is your answer. You probably changed something in xaml and forgot to make the equivalent change in your codebehind file. — , Apr 09 '15 at 14:13
https://social.msdn.microsoft.com/Forums/getfile/643604. I don't have enough to upload photo. — nogaku nogaku1987, Apr 09 '15 at 14:15

score 1 · Answer 1 · answered Apr 09 '15 at 05:21

1

What I see, first on "The Final" I don't see where is defined the datacontext of the Page because the datacontext should be:

<Page.DataContext>
  <vm:MainWindowViewModel />
</Page.DataContext/>

Or if you prefer

<Page ... DataContext="{Binding StaticResource=ViewModel}"...>
 <Page.Resources>
  <vm:MainWindowViewModel x:Key="ViewModel"/>
 </Page.Resources>
</Page>

Then there is no 'ViewModel' property inside MainViewModel you defined ViewModels, so it should be

<ListBox x:Name="lstMainMenu" SelectionChanged="lstMainMenu_SelectionChanged" Background="Transparent"
ItemsSource="{Binding ViewModels}">

DataTemplateSelector is empty and is used for other logic.

answered Apr 09 '15 at 05:21

Juan Pablo Garcia Coello

3,192
1
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33

Inside app.cs is true??var viewModel = new MainWindowModel(); MainPage main = new MainPage(); main.DataContext = viewModel; – nogaku nogaku1987 Apr 09 '15 at 05:46
Listbox is getting "mixnokia.viewmodel.menulistviewmodel – nogaku nogaku1987 Apr 09 '15 at 05:48
Ok it is not the best place but you can do it there for the purpose, but did you changed the 'Viewmodel' to 'ViewModels' in the binding of itemssource? – Juan Pablo Garcia Coello Apr 09 '15 at 06:10
Your idea is put var viewmodel through mainpage.cs over. – nogaku nogaku1987 Apr 09 '15 at 07:45
But what is that to datacontext? Listbox.itemsource or page.itemsource – nogaku nogaku1987 Apr 09 '15 at 07:47
It does not really matter, the matter is if you hace tested changing the xaml to binding vuewmodels in plural like your property – Juan Pablo Garcia Coello Apr 09 '15 at 07:48
I dont understand. Listbox is just getting "mixnokia.viewmodel.menulistviewmodel ". Where is wrong? – nogaku nogaku1987 Apr 09 '15 at 08:01
In Page you have here change to ViewModels to make the ListBox set the ViewModels instance of the MainViewModel – Juan Pablo Garcia Coello Apr 09 '15 at 08:44
. It also look like old code – nogaku nogaku1987 Apr 09 '15 at 09:11
"mixnokia.viewmodel.menulistviewmodel ". – nogaku nogaku1987 Apr 09 '15 at 09:11
What does this have to do with the error? "Partial declarations of 'MenuListBox' must not specify different base classes" His code is a horrible mess, yes, but this isn't about all the other fail he's managed to cram into this question. – Apr 09 '15 at 14:14

The first time for MVVM and I got a error. So I did not know where is error

1 Answers1