inotifypropertychanged | 易学教程

WPF MVVM INotifyPropertyChanged Implementation - Model or ViewModel

阅读更多关于 WPF MVVM INotifyPropertyChanged Implementation - Model or ViewModel

I have read a number of debates on where to implement INotifyPropertyChanged here on StackOverflow and other blogs but it seems that there are cases where you have to implement it on the Model. Here is my scenario - I am looking for feedback on my conclusion or is my approach wrong. I am using this implementation of an ObservableDictionary ( ObservableDictionary ) because I need performant queries using the key. In this dictionary I place the collection of Model objects. In my VM, I declare an instance (Books) of the dictionary and in the XAML bind to it. <tk:DataGrid AutoGenerateColumns=

How to raise PropertyChanged event without using string name

阅读更多关于 How to raise PropertyChanged event without using string name

It would be good to have ability to raise 'PropertyChanged' event without explicit specifying the name of changed property. I would like to do something like this: public string MyString { get { return _myString; } set { ChangePropertyAndNotify<string>(val=>_myString=val, value); } } private void ChangePropertyAndNotify<T>(Action<T> setter, T value) { setter(value); PropertyChangedEventHandler handler = PropertyChanged; if (handler != null) { handler(this, new PropertyChangedEventArgs(setter.Method.Name)); } } In this case received name is a name of lambda-method: "<set_MyString>b__0". Can I

Automatic INotifyPropertyChanged Implementation through T4 code generation?

阅读更多关于 Automatic INotifyPropertyChanged Implementation through T4 code generation?

问题 I'm currently working on setting up a new project of mine and was wondering how I could achieve that my ViewModel classes do have INotifyPropertyChanged support while not having to handcode all the properties myself. I looked into AOP frameworks but I think they would just blow up my project with another dependency. So I thought about generating the property implementations with T4. The setup would be this: I have a ViewModel class that declares just its Properties background variables and

Subscribe to INotifyPropertyChanged for nested (child) objects

阅读更多关于 Subscribe to INotifyPropertyChanged for nested (child) objects

问题 I'm looking for a clean and elegant solution to handle the INotifyPropertyChanged event of nested (child) objects. Example code: public class Person : INotifyPropertyChanged { private string _firstName; private int _age; private Person _bestFriend; public string FirstName { get { return _firstName; } set { // Short implementation for simplicity reasons _firstName = value; RaisePropertyChanged("FirstName"); } } public int Age { get { return _age; } set { // Short implementation for simplicity

How to get property change notifications with EF 4.x DbContext generator

阅读更多关于 How to get property change notifications with EF 4.x DbContext generator

I'm playing around with Entity Framework 4.3, and so I am using the DbContext Generator to create the context and entity classes. With the default EF 4 code generator template, entity classes implement INotifyPropertyChanged, and also add Changing and Changed partial methods in property setters. When I use the EF 4.x DbContext generator, as pictured below, the entity classes are much lighter, and do not include any means of tracking property changes. Here is an example: //------------------------------------------------------------------------------ // <auto-generated> // This code was

Implementing NotifyPropertyChanged without magic strings [duplicate]

阅读更多关于 Implementing NotifyPropertyChanged without magic strings [duplicate]

问题 This question already has answers here : Closed 7 years ago . Possible Duplicate: typesafe NotifyPropertyChanged using linq expressions I'm working on a large team application which is suffering from heavy use of magic strings in the form of NotifyPropertyChanged("PropertyName") , - the standard implementation when consulting Microsoft. We're also suffering from a great number of misnamed properties (working with an object model for a computation module that has hundreds of stored calculated

Simplest way to achieve automatic notification of property change

阅读更多关于 Simplest way to achieve automatic notification of property change

问题 I know that there are solutions out there for implementing INotifyPropertyChanged, but none of them are as simple as: reference this library, create/add this attribute, done (I'm thinking Aspect-Oriented Programming here). Does anyone know of a really simple way to do this? Bonus points if the solution is free. Here are some relevant links (none of which provide a simple enough answer): Aspect Examples (INotifyPropertyChanged via aspects) LinFu INotifyPropertyChanged auto wiring or how to get

In MVVM model should the model implement INotifyPropertyChanged interface?

阅读更多关于 In MVVM model should the model implement INotifyPropertyChanged interface?

I have clear idea about View and ViewModel in MVVM pattern. I am planning to implement MVVM pattern in my application. I'm facing an issue regarding the model. I have .xml file which is parsed and the information is displayed in the View. I need to be notified about the changes in the model for the first time only. From onwards on demand I need to be notified. So how to implement the model? Should I implement INotifyPropertyChanged interface in model class also? (I read that model should not implement INotifyPropertyChanged interface, since it is WPF specific) Implementing

How to implement INotifyPropertyChanged in C# 6.0?

阅读更多关于 How to implement INotifyPropertyChanged in C# 6.0?

问题 The answer to this question has been edited to say that in C# 6.0, INotifyPropertyChanged can be implemented with the following OnPropertyChanged procedure: protected void OnPropertyChanged([CallerMemberName] string propertyName = null) { PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName)); } However, it isn't clear from that answer what the corresponding property definition should be. What does a complete implementation of INotifyPropertyChanged look like in C# 6.0 when

typesafe NotifyPropertyChanged using linq expressions

阅读更多关于 typesafe NotifyPropertyChanged using linq expressions

问题 Form Build your own MVVM I have the following code that lets us have typesafe NotifyOfPropertyChange calls: public void NotifyOfPropertyChange<TProperty>(Expression<Func<TProperty>> property) { var lambda = (LambdaExpression)property; MemberExpression memberExpression; if (lambda.Body is UnaryExpression) { var unaryExpression = (UnaryExpression)lambda.Body; memberExpression = (MemberExpression)unaryExpression.Operand; } else memberExpression = (MemberExpression)lambda.Body;