C#•2y ago

❔ OnpropertyChanged WPF

Hi everyone, i have _stepStore_PropertyChanged which is subscribe to _stepStore.PropertyChanged and i do not understand why my method is trigger twice ? if i put a breakpoint on the on both side one on the propertychanged in _stepStore and the other one in the method it not match like there is only one trigger inside _stepstore against 2 for the method.

3 Replies

Klarth•2y ago

Looks like a bit of a mess. It's unusual (IMO) for a VM to subscribe to PropertyChanged, though not unheard of. I would try ruling out subscribing to the event twice, somehow, as that's the most likely culprit. Besides that, use the call stack when inside _stepStore_PropertyChanged to see exactly where each call is coming from.

ElioOP•2y ago

if i do not subscribe to _stepStore.propertychanged how i'm am supposed to trigger the propertyChanged() in ListingStepViewModel when _steps change ?

public class ListingStepViewModel : ViewModelBase
    {
        private readonly StepStore _stepStore;
        public IEnumerable<StepViewModel>? Steps => _stepStore.Steps;

        public StepViewModel? CurrentStep
        {
            get
            {
                return _stepStore.CurrentStep;
            }
            set
            {
                _stepStore.CurrentStep = value;
                OnPropertyChanged();
            }
        }
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public class ListingStepViewModel : ViewModelBase
    {
        private readonly StepStore _stepStore;
        public IEnumerable<StepViewModel>? Steps => _stepStore.Steps;

        public StepViewModel? CurrentStep
        {
            get
            {
                return _stepStore.CurrentStep;
            }
            set
            {
                _stepStore.CurrentStep = value;
                OnPropertyChanged();
            }
        }
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  .
  .

Accord•2y ago

Was this issue resolved? If so, run /close - otherwise I will mark this as stale and this post will be archived until there is new activity.

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❔ OnpropertyChanged WPF