考虑下面的过滤器:
var builder = Builders<Product>.Filter;
var filter = builder.Gte(i => i.Price, criteria.MinPrice) &
builder.Lte(i => i.Price, criteria.MaxPrice);
if (0 != criteria.CategoryId)
//Combine the following filter with the previous filter. How??
var criteriaFilter = builder.Eq(i => i.CategoryId, criteria.CategoryId);
如何将criteriaFilter和filter结合起来?