Using WPF Validation rules and the disabling of a 'Save' button

Question

I have a page where a few textboxes cannot be empty before clicking a Save button.

Answer 1

just inhert your ViewModel from System.ComponentModel.IDataErrorInfo for Validate and from INotifyPropertyChanged to notify button

make property:

    public bool IsValid
    {
        get
        {
            if (this.FloorPlanName.IsEmpty())
                return false;
            return true;
        }
    }

in xaml, connect it to button

in the IDataErrorInfo overrides, notify btutton

public string this[string columnName]{
        get
        {
            switch (columnName)
            {
                case "FloorPlanName":
                    if (this.FloorPlanName.IsEmpty())
                    {
                        OnPropertyChanged("IsValid");
                        return "Floor plan name cant be empty";
                    }
                    break;
            }
        }
}