public static DesignPropertyCollection GetProperties(DependencyObject obj)
{
if (obj == null)
{
throw new ArgumentNullException(nameof(obj));
}
if (obj.GetValue(PropertiesProperty) is DesignPropertyCollection col)
{
return(col);
}
col = new DesignPropertyCollection(obj);
SetProperties(obj, col);
return(col);
}
private static void SetProperties(DependencyObject obj, DesignPropertyCollection value)
{
obj.SetValue(PropertiesPropertyKey, value);
}
