Enable button based on TextBox value (WPF)

Things look much clearer now with the edits, thanks! This might be a stupid question (I'm somewhat tired of a long day's work), but why don't you bind to the command directly, instead of through a static resource?

<Button Command="{Binding AddObjectCommand}">Add</Button>

Since you are using the DelegateCommand, you can call it's RaiseCanExecuteChanged method when your text property changes. I'm not sure what you are trying to accomplish with your CommandReference resource, but typically you just bind the commands directly to the button element's Command property:

<TextBox Text="{Binding ObjectName, UpdateSourceTrigger=ValueChanged}" />
<Button Command="{Binding AddObjectCommand}" Content="Add" />

This would be the relevant portion of your view model:

public string ObjectName
{
    get { return objectName; }
    set
    {
        if (value == objectName) return;
        value = objectName;
        AddObjectCommand.RaiseCanExecuteChanged();
        OnPropertyChanged("ObjectName");
    }
}