BaseClass Command class in a MVVM-like App using delegates example/explanation

namespace crud2WSearch.Commands
{
    public class PopupCommand : ICommand
    {
        public event EventHandler? CanExecuteChanged;

        private Action<object> _Execute { get; set; }
        private Predicate<object> _CanExecute { get; set; }

        public PopupCommand(Action<object> ExecuteMethod, Predicate<object> CanExecuteMethod)
        {
            _Execute = ExecuteMethod;
            _CanExecute = CanExecuteMethod;
        }

        public bool CanExecute(object? parameter)
        {
            return _CanExecute(parameter);
        }

        public void Execute(object? parameter)
        {
            _Execute(parameter);
        }
    }
}

This code defines a class named PopupCommand that implements the ICommand interface.

The ICommand interface is commonly used in WPF and other XAML-based frameworks to represent a command that can be bound to user interface elements such as buttons.

Explanation as follows:

1. ICommand Interface:

• The ICommand interface provides a standard way to handle commands in a user interface.
• It includes the CanExecute and Execute methods, along with the CanExecuteChanged event.

2. PopupCommand Class:

• The PopupCommand class implements the ICommand interface.

3. CanExecuteChanged Event:

• This is an event of type EventHandler that is part of the ICommand interface. It is raised whenever the conditions for whether the command can execute (via the CanExecute method) may have changed.
• In this implementation, the event is nullable (EventHandler?) to indicate that it might be null.

4. Private Properties:

• _Execute is a private property of type Action<object>. It represents the method to be executed when the command is invoked.
• _CanExecute is a private property of type Predicate<object>. It represents the method that determines whether the command can execute in its current state.

5. Constructor:

• The constructor takes two parameters: ExecuteMethod (an Action<object>) and CanExecuteMethod (a Predicate<object>). These parameters are used to initialize the _Execute and _CanExecute properties, respectively.

6. CanExecute Method:

• The CanExecute method is required by the ICommand interface. It checks whether the command can execute in its current state. It delegates this responsibility to the _CanExecute method provided during construction.

7. Execute Method:

• The Execute method is required by the ICommand interface. It is called when the command is invoked. It delegates the execution to the _Execute method provided during construction.

This class is designed to encapsulate the logic associated with a command, making it easy to create instances of ICommand in a concise way.

This is especially useful when defining commands for user interface elements like buttons in XAML-based frameworks.

It allows developers to specify the execution and can-execute logic in a clean and straightforward manner.