WPF 区分设计状态和运行状态 代码

   var prop = System.ComponentModel.DesignerProperties.IsInDesignModeProperty;
            bool isInDesignMode = (bool)System.ComponentModel.DependencyPropertyDescriptor
                .FromProperty(prop, typeof(FrameworkElement))
                .Metadata.DefaultValue;

   摘自 Simple MVVM Toolkit