C#•5d ago

Binding doesn't update for some reason

Hey, i'm having some wierd issues with binding not updating in wpf, here's the relevant code: (the issue is that the item count in the player inventory doesn't update on display) TradeView.xaml (lines 23-48) TradeViewViewModel (lines 49-59) PlayerViewModel InventoryViewModel ItemViewModel ViewModelBase

21 Replies

Nasdack•5d ago

You are updating the collection by the indexer which I don't believe is tracked by the binding engine so call OnPropertyChanged explicitly after performing your update

Mąż Zuzanny Harmider SzczęścieOP•5d ago

        private void Trade(TradeViewModel trade)
        {
            if (trade == null) return;
            if (Player.Inventory.Items.ContainsKey(trade.TradeOut.Key))
                Player.Inventory.Items[trade.TradeOut.Key].Count = Player.Inventory.Items[trade.TradeOut.Key].Count - trade.TradeOut.Value;
            OnPropertyChanged(nameof(Player.Inventory.Items));
            if (Player.Inventory.Items.ContainsKey(trade.TradeIn.Key))
                Player.Inventory.Items[trade.TradeIn.Key].Count = Player.Inventory.Items[trade.TradeIn.Key].Count - trade.TradeIn.Value;
            OnPropertyChanged(nameof(Player.Inventory.Items));
            Debug.WriteLine($"{trade.TradeOut.Key}: {Player.Inventory.Items[trade.TradeOut.Key].Count}");
            Debug.WriteLine($"{trade.TradeIn.Key}: {Player.Inventory.Items[trade.TradeIn.Key].Count}");
            TradeCommand.RaiseCanExecuteChanged();
        }

        private void Trade(TradeViewModel trade)
        {
            if (trade == null) return;
            if (Player.Inventory.Items.ContainsKey(trade.TradeOut.Key))
                Player.Inventory.Items[trade.TradeOut.Key].Count = Player.Inventory.Items[trade.TradeOut.Key].Count - trade.TradeOut.Value;
            OnPropertyChanged(nameof(Player.Inventory.Items));
            if (Player.Inventory.Items.ContainsKey(trade.TradeIn.Key))
                Player.Inventory.Items[trade.TradeIn.Key].Count = Player.Inventory.Items[trade.TradeIn.Key].Count - trade.TradeIn.Value;
            OnPropertyChanged(nameof(Player.Inventory.Items));
            Debug.WriteLine($"{trade.TradeOut.Key}: {Player.Inventory.Items[trade.TradeOut.Key].Count}");
            Debug.WriteLine($"{trade.TradeIn.Key}: {Player.Inventory.Items[trade.TradeIn.Key].Count}");
            TradeCommand.RaiseCanExecuteChanged();
        }

still nothing @Nasdack i did this the same in GameViewModel and it works fine...

Nasdack•5d ago

Can I see your GameView.xaml?

Mąż Zuzanny Harmider SzczęścieOP•5d ago

https://github.com/JuanNotTheHuman/TileGame/blob/master/Views/GameView.xaml

Qwerz•5d ago

From what I can tell you're not calling OnPropertyChanged when the value updates

Mąż Zuzanny Harmider SzczęścieOP•5d ago

it does update tho, and im calling it

Qwerz•5d ago

Your model does not implement INotifyPropertyChanged

Mąż Zuzanny Harmider SzczęścieOP•5d ago

code:

        private void Trade(TradeViewModel trade)
        {
            if (trade == null) return;

            var items = PlayerViewModel.Inventory.Items;

            if (items.TryGetValue(trade.TradeOut.Key, out var tradeOutItem))
            {
                tradeOutItem.Count -= trade.TradeOut.Value;
            }

            if (items.TryGetValue(trade.TradeIn.Key, out var tradeInItem))
            {
                tradeInItem.Count += trade.TradeIn.Value;
            }
            Debug.WriteLine($"{trade.TradeOut.Key}: {tradeOutItem?.Count}");
            Debug.WriteLine($"{trade.TradeIn.Key}: {tradeInItem?.Count}");
//viewmodelbase
              public class ViewModelBase : INotifyPropertyChanged
    {
        public event PropertyChangedEventHandler PropertyChanged;
        protected void OnPropertyChanged([CallerMemberName]string propertyName=null)
        {
            Debug.WriteLine($"Property changed: {propertyName}");
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
        }
    }

        private void Trade(TradeViewModel trade)
        {
            if (trade == null) return;

            var items = PlayerViewModel.Inventory.Items;

            if (items.TryGetValue(trade.TradeOut.Key, out var tradeOutItem))
            {
                tradeOutItem.Count -= trade.TradeOut.Value;
            }

            if (items.TryGetValue(trade.TradeIn.Key, out var tradeInItem))
            {
                tradeInItem.Count += trade.TradeIn.Value;
            }
            Debug.WriteLine($"{trade.TradeOut.Key}: {tradeOutItem?.Count}");
            Debug.WriteLine($"{trade.TradeIn.Key}: {tradeInItem?.Count}");
//viewmodelbase
              public class ViewModelBase : INotifyPropertyChanged
    {
        public event PropertyChangedEventHandler PropertyChanged;
        protected void OnPropertyChanged([CallerMemberName]string propertyName=null)
        {
            Debug.WriteLine($"Property changed: {propertyName}");
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
        }
    }

output:

Property changed: Count
Property changed: Count
Mushroom: -2
Honey: 3

Property changed: Count
Property changed: Count
Mushroom: -2
Honey: 3

it does

Qwerz•5d ago

Looking at it, can't see that it does.

Mąż Zuzanny Harmider SzczęścieOP•5d ago

TradeViewViewModel ViewModelBase

Qwerz•5d ago

model

Mąż Zuzanny Harmider SzczęścieOP•5d ago

Qwerz•5d ago

not viewmodel

Mąż Zuzanny Harmider SzczęścieOP•5d ago

the model shouldn't integrate inotify, it's against mvvm this is all the relevant code

Qwerz•5d ago

Now why would that be

Mąż Zuzanny Harmider SzczęścieOP•5d ago

coz a model is for static stuff i have both model and viewmodel couterparts for everything

Qwerz•5d ago

Implementing INPC in a model that holds states is absolutely not against MVVM

Mąż Zuzanny Harmider SzczęścieOP•5d ago

what model do you want tho, i dont understand like what doesnt that have to do with the binding

Qwerz•5d ago

You're trying to update a property of Player

FusedQyou•5d ago

I think you'd do yourself a massive favour if you get rid of all the manual INPC invokation and download a package like CommunityToolkit that does it for you

Mąż Zuzanny Harmider SzczęścieOP•5d ago

ill try it ig did it, still doesnt work viewmodels @FusedQyou ? i tried even coding it from scratch with the toolkit in mind, still nothing

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Binding doesn't update for some reason

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