如果您必须保留静态方法，我会将静态调用包装在存储库中

If you must keep the static method, I would wrap the static calls in a Repository object.

就像这样：

interface IOrderRepository {
   IEnumerable<IOrder> GetAll(customerId, ..);
}

class OrderRepository : IOrderRepository {
   IEnumerable<IOrder> GetAll(customerId, ...)
   {
     Order.GetAll(customerId,...); // The original static call.
   }
}

现在您将此存储库注入到 Customer 类。

Now you inject this repository into your Customer class.

（我假设您正在这样做，因此可以在运行时注入伪造的IOrder进行测试。应该说总体上来说，静态方法是测试的严重障碍。）

(I'm assuming you're doing this so you can inject fake IOrders at runtime for testing purposes. I should say that in general, static methods are a serious obstacle to testing.)