/// <summary>
/// 获得画布上下文中所有可见的图层;
/// </summary>
/// <param name="cadContext"></param>
/// <returns></returns>
public static IEnumerable <CanvasLayer> GetVisibleLayers(this ICADContext cadContext)
{
if (cadContext == null)
{
throw new ArgumentNullException(nameof(cadContext));
}
return(cadContext.Layers?.Where(p => p.IsVisible) ?? Enumerable.Empty <CanvasLayer>());
}
/// <summary>
/// 获取画布上下文中所有绘制对象;
/// </summary>
/// <param name="cadContext"></param>
/// <returns></returns>
public static IEnumerable <DrawObject> GetAllDrawObjects(this ICADContext cadContext)
{
if (cadContext == null)
{
throw new ArgumentNullException(nameof(cadContext));
}
return(cadContext.Layers?.SelectMany(p => p.DrawObjects) ?? Enumerable.Empty <DrawObject>());
}
/// <summary>
/// 获取指定类型的画布上下文中可见的绘制对象;
/// </summary>
/// <param name="cadContext"></param>
/// <returns></returns>
public static IEnumerable <TDrawObject> GetAllVisibleDrawObjects <TDrawObject>(this ICADContext cadContext) where TDrawObject : DrawObject
{
return(GetAllDrawObjects(cadContext).Select(p => p as TDrawObject).Where(p => p != null));
}
