Query Categories

Categories can be retrieved using the ICategoryService or using the Query method or Load method

var categoryService = client.CreateChannel<ICategoryService>();
var allCategoriesInATree = categoryService.GetCategories();
//or using Query
var allCategoriesInATree2 = client.Query<Category>().ToList();

If you use the Query method or Load method you can also apply filters and include statements

Filters

You can filter categories by id

var category3 = client.Query<Category>().Where(c => c.Id == 3).FirstOrDefault();
//or using Load
var category4 = client.Load<Category>(4).FirstOrDefault();

or by parent id

var childCategories = client.Query<Category>().Where(c => c.ParentId == 3).ToList();

Includes

You can opt in to populate the IsUsed property.

var categories = client.Query<Category>().Include(c => c.IsUsed).ToList();