Dynamically subscribe to events in a method?

Question

Introduction

In my current WPF project I quite regularly had to convert DataTables into Lists of model classes, like this:

public void CreateExmapleModeList()
{
    ExampleModels = new List<ExampleModel>();
    foreach (DataRow row in tbl)
    {
        ExampleModel example = new ExampleModel
        {
            Name = row["Name"].ToString(),
            Tag = row["Tag"].ToString(),
            Value = double.Parse(row["Value"].ToString()),
            // [...]

        };
        ExampleModels.Add(example);
        example.PropertyChanged += ExampleModel_PropertyChanged;
    }
}

assinging dozens of properties for dozens of lists is quite annoying, so I googled a little and found this quite handy answer on StackOverflow to assign properties dynamically, which cut down creating new lists to this:

ExampleModels = ListConverter.ConvertToList<ExampleModel>(tbl);

Problem

Now after refactoring my code I didn't know how to subscribe my custom PropertyChanged-Event to the PropertyChanged-Event of my model, so I simply iterated through the whole list again:

foreach (ExampleModel exmp in ExampleModels)
{
    example.PropertyChanged += ExampleModel_PropertyChanged;
}

PropertyChanged:

public void ExampleModel_Propertychanged(object sender, PropertyChangedEventArgs e)
{
    //do something
}

Question

I would much rather subscribe to the PropertyChanged-Event when creating the list rather then redundantly iterate a second time through the whole list.

Since there are quite a few Models, which have custom PropertyChanged-Events I need to subscribe them dynamically.

Is there a way simular to the RelayCommand for example:

public RelayCommand(Action<T> execute, Predicate<T> canExecute)
{
    m_execute = execute ?? throw new ArgumentNullException("execute");
    m_canExecute = canExecute;

}

to tell my ContVertToList-Method which event it has to subscirbe like:

ExampleModels = ListConverter.ConvertToList<ExampleModel>(tbl, ExampleModel_Propertychanged(object sender, PropertyChangedEventArgs e));

and in ConvertToList something like this:

public static List<T> ConvertToList<T>(DataTable dt, CustomPropertyChanged<S, E>) where T : TemplateModel

 // [...]
 objT.PropertyChanged = CustomPropertyChanged;
 return onjT;
 }).ToList();

score 2 · Accepted Answer · answered Jun 14 '19 at 13:22

You could pass a PropertyChangedEventHandler to your method and hook it up using the += syntax:

public static List<T> ConvertToList<T>(DataTable dt, PropertyChangedEventHandler eventHandler) where T : INotifyPropertyChanged
{
    //...
    objT.PropertyChanged += eventHandler;
}

Usage:

var list = ConvertToList<YourType>(dataTable, ExampleModel_Propertychanged);
...
private void ExampleModel_Propertychanged(object sender, PropertyChangedEventArgs e)
{
    //do something
}

holy moly. This looks so easy, but i guess I would have never figured it out on my own. Thank you very much. — Azzarrel, Jun 14 '19 at 17:44

Dynamically subscribe to events in a method?

Introduction

Problem

Question

1 Answers1