AsyncCommand

AsyncCommand.cs

class AsyncCommand : ICommand, INotifyPropertyChanged
{
    public AsyncCommand(Func<Task> Action)
    {
        action = Action;
        canExecute = true;
    }

    public event EventHandler CanExecuteChanged;

    public event PropertyChangedEventHandler PropertyChanged;

    public bool CanExecute(object parameter)
    {
        return !IsExecuting && canExecute;
    }

    public async void Execute(object parameter)
    {
        if (IsExecuting)
            return;
        try
        {
            IsExecuting = true;
            await action();
        }
        catch
        {
            //
        }
        finally
        {
            IsExecuting = false;
        }
    }

    public bool IsExecuting
    {
        get { return isExecuting; }
        set
        {
            isExecuting = value;
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs("IsExecuting"));
            OnCanExecuteChanged();
        }
    }
    private bool isExecuting;

    public void OverrideCanExecute(bool Value)
    {
        canExecute = Value;
        OnCanExecuteChanged();
    }

    private Func<Task> action;
    private bool canExecute;

    private void OnCanExecuteChanged()
    {
        CanExecuteChanged?.Invoke(this, EventArgs.Empty);
    }
}