vue-java-tutorials/CSharp/WPFTutorial/WPF-23-MVVMRelayCommand/MVVM/RelayCommand.cs

using System.Windows.Input;

namespace WPF_23_MVVMRelayCommand.MVVM;

public class RelayCommand : ICommand
{
    private readonly Action<object> _execute;
    private readonly Func<object, bool>? _canExecute;

    public RelayCommand(Action<object> execute, Func<object, bool>? canExecute = null)
    {
        _execute = execute;
        _canExecute = canExecute;
    }

    public event EventHandler? CanExecuteChanged
    {
        add => CommandManager.RequerySuggested += value;
        remove => CommandManager.RequerySuggested -= value;
    }

    public bool CanExecute(object? parameter)
    {
        return _canExecute == null || _canExecute(parameter!);
    }

    public void Execute(object? parameter)
    {
        _execute(parameter!);
    }
}