WPF advanced development and wpf advanced development

WPF advanced development and wpf advanced development
INotifyPropertyChanged

In the development of the wpf mvvm mode, the ViewModel that implements INotifyPropertyChanged is very important and common class:

public class MainViewModel : INotifyPropertyChanged{    public event PropertyChangedEventHandler PropertyChanged;    private void OnPropertyChanged(string propertyName)    {        if (this.PropertyChanged != null)            this.PropertyChanged(this, new PropertyChangedEventArgs(propertyName));    }}

In the class, all attributes that need to respond to changes must call the property change method in Setter:

private string _appName;public string AppName{    get    {        return _appName;    }    set    {        if (_appName == value)            return;        _appName = value;        OnPropertyChanged(nameof(AppName));    }}

In this way, one or two attributes are okay. When there are many attributes, they seem complicated. Today, we want to introduce an open-source tool to solve this problem.

Fody/PropertyChanged

Open Source Address: https://github.com/Fody/PropertyChanged/

INotifyPropertyChanged code in the property during compilation

Usage

<?xml version="1.0" encoding="utf-8"?><Weavers>  <PropertyChanged /></Weavers>

Description

All the classes marked with the [ImplementPropertyChanged] feature or INotifyPropertyChanged feature in the project automatically implement notification-related code in their properties, unless the property is marked as not notified

• Code in the program:

[ImplementPropertyChanged]public class Person {            public string GivenNames { get; set; }    public string FamilyName { get; set; }    public string FullName    {        get        {            return string.Format("{0} {1}", GivenNames, FamilyName);        }    }}

Or

public class MainViewModel : INotifyPropertyChanged{   public string GivenNames { get; set; }   public string FamilyName { get; set; }   public string FullName   {       get       {           return string.Format("{0} {1}", GivenNames, FamilyName);       }   }      public event PropertyChangedEventHandler PropertyChanged;   private void OnPropertyChanged(string propertyName)   {       if (this.PropertyChanged != null)           this.PropertyChanged(this, new PropertyChangedEventArgs(propertyName));   }}

• After compilation

public class Person : INotifyPropertyChanged{   public event PropertyChangedEventHandler PropertyChanged;   string givenNames;   public string GivenNames   {       get { return givenNames; }       set       {           if (value != givenNames)           {               givenNames = value;               OnPropertyChanged("GivenNames");               OnPropertyChanged("FullName");           }       }   }   string familyName;   public string FamilyName   {       get { return familyName; }       set        {           if (value != familyName)           {               familyName = value;               OnPropertyChanged("FamilyName");               OnPropertyChanged("FullName");           }       }   }   public string FullName   {       get       {           return string.Format("{0} {1}", GivenNames, FamilyName);       }   }   public virtual void OnPropertyChanged(string propertyName)   {       var propertyChanged = PropertyChanged;       if (propertyChanged != null)       {           propertyChanged(this, new PropertyChangedEventArgs(propertyName));       }   }}