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RehanSaeed
[Comment] Model-View-ViewModel (MVVM) - Part 3 - INotifyPropertyChanged
https://rehansaeed.com/model-view-viewmodel-mvvm-part3-inotifypropertychanged/
Thanks, your wrapped property really helped me.
I think you missed out the equals check in the two SetProperty functions though
if (equal()) return false;
Thanks, your wrapped property really helped me.
I think you missed out the equals check in the two
SetPropertyfunctions thoughif (equal()) return false;
Thanks for the comment Mahgnilloc. I've updated the code to reflect your comment.
Thanks for the comment Mahgnilloc. I've updated the code to reflect your comment.
Your blog series on mvvm is helping me a lot, thanks.. the SetProperty should be bool instead of void.
Your blog series on mvvm is helping me a lot, thanks.. the
SetPropertyshould be bool instead of void.
Well spotted, thanks. Fixed.
Disposable cannot be inherited anymore ...do you see any other alternatives?
Disposablecannot be inherited anymore ...do you see any other alternatives?
Not sure what you mean. Have you set the class to sealed?
Hello Rehan,
Great implementation.
Just a minor finding:
I guess there's a typo in your 'Dealing with Wrapped Objects' example. The == and = should be flipped.
Have a great weekend Dieter
Hello Rehan,
Great implementation.
Just a minor finding: I guess there's a typo in your 'Dealing with Wrapped Objects' example. The
==and=should be flipped.Have a great weekend Dieter
Actually no, the second delegate is passed to determine whether the two objects are equal. Only if they are equal, do we raise a property changed event.
Actually no, the second delegate is passed to determine whether the two objects are equal. Only if they are equal, do we raise a property changed event.
Hello Rehan,
Are you sure? The procedure is
protected Boolean SetProperty(Func equal, Action action, [CallerMemberName] String propertyName = null)
So the first delegate seems to be the equality check.
Testing your example only works if I'm using
set { this.SetProperty(() => this.catCount.Count == value, () => this.catCount.Count = value); }
Instead of
set { this.SetProperty(() => this.catCount.Count = value, () => this.catCount.Count == value); }
Hello Rehan,
are you sure? The procedure is
protected Boolean SetProperty(Func equal, Action action, [CallerMemberName] String propertyName = null)So the first delegate seems to be the equality check.
Testing your example only works if I'm using
set { this.SetProperty(() => this.catCount.Count == value, () => this.catCount.Count = value); }Instead of
set { this.SetProperty(() => this.catCount.Count = value, () => this.catCount.Count == value); }
Scratch that, you are absolutely correct sir! It's been some time since I've looked at this code.
Scratch that, you are absolutely correct sir! It's been some time since I've looked at this code.
Maybe update the example to reflect this change?
Maybe update the example to reflect this change?
Thanks, have done so!
I want to ask you if I could have the permission to use your code freely.
I want to ask you if I could have the permission to use your code freely.
The code in this post is MIT licensed.
This INotifyPropertyChanged base implementation seems very useful to me - thank you!
I'm confused about the Debug.Assert condition shown:
string.IsNullOrEmpty(propertyName) || (this.GetType().GetRuntimeProperty(propertyName) != null)
Shouldn't that be like this instead?
(!string.IsNullOrEmpty(propertyName)) && (this.GetType().GetRuntimeProperty(propertyName) != null)
But I'm unfamiliar with the actual meaning of this.GetType().GetRuntimeProperty(propertyName), so I'm just confused.
This
INotifyPropertyChangedbase implementation seems very useful to me - thank you!I'm confused about the
Debug.Assertcondition shown:string.IsNullOrEmpty(propertyName) || (this.GetType().GetRuntimeProperty(propertyName) != null)Shouldn't that be like this instead?
(!string.IsNullOrEmpty(propertyName)) && (this.GetType().GetRuntimeProperty(propertyName) != null)But I'm unfamiliar with the actual meaning of
this.GetType().GetRuntimeProperty(propertyName), so I'm just confused.
A null or empty property name is actually valid. It signals that all of the properties on the view model have changed and that they should be refreshed in the XAML bindings.