How to bind to property with only get accessor

c#, mvvm, viewmodel, wpf

Solution

The proper way to deal with buttons is to implement ICommand interface. Here is an example from my solution:

public class RelayCommand : ICommand
{
    readonly Action<object> _execute;
    readonly Predicate<object> _canExecute;

    public RelayCommand(Action<object> execute) : this(execute, null)
    {
    }

    public RelayCommand(Action<object> execute, Predicate<object> canExecute)
    {
        if (execute == null)
            throw new ArgumentNullException("execute");

        _execute = execute;
        _canExecute = canExecute;           
    }

    #region ICommand Members

    public bool CanExecute(object parameter)
    {
        return _canExecute == null ? true : _canExecute(parameter);
    }

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

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

    #endregion
}

You can then databind to button like this:

<Button Command="{Binding MyCommand}" .../>

Whats left is to declare an `ICommand` property on your viewmodel:

public ICommand MyCommand { get; private set; }

//in constructor:
MyCommand = new RelayCommand(_ => SomeActionOnButtonClick(), _ => HasChanges);

The state of the button will then automatically update on most changes. If it doesnt for some reason - you can force the update by calling `CommandManager.InvalidateRequerySuggested`

Problem

Original source