Published: Jul 23, 2019 by Jenno Vink
PropertyChanged.Fody
When using the MVVM pattern in C# I think it’s very useful to use PropertyChanged.Fody. It injects code at compile time and as a result, the code becomes cleaner and better readable.
Before code:
public class Person : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
public string GivenNames { get; set; }
public string FamilyName { get; set; }
public string FullName => $"{GivenNames} {FamilyName}";
}
What gets compiled:
public class Person : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
string givenNames;
public string GivenNames
{
get => givenNames;
set
{
if (value != givenNames)
{
givenNames = value;
OnPropertyChanged(InternalEventArgsCache.GivenNames);
OnPropertyChanged(InternalEventArgsCache.FullName);
}
}
}
string familyName;
public string FamilyName
{
get => familyName;
set
{
if (value != familyName)
{
familyName = value;
OnPropertyChanged(InternalEventArgsCache.FamilyName);
OnPropertyChanged(InternalEventArgsCache.FullName);
}
}
}
public string FullName => $"{GivenNames} {FamilyName}";
protected void OnPropertyChanged(PropertyChangedEventArgs eventArgs)
{
PropertyChanged?.Invoke(this, eventArgs);
}
}
internal static class InternalEventArgsCache
{
internal static PropertyChangedEventArgs FamilyName = new PropertyChangedEventArgs("FamilyName");
internal static PropertyChangedEventArgs FullName = new PropertyChangedEventArgs("FullName");
internal static PropertyChangedEventArgs GivenNames = new PropertyChangedEventArgs("GivenNames");
}
What a tremendous improvement!
