void InitializationData() { SingleSource.Add("Asia"); SingleSource.Add("Europe"); SingleSource.Add("America"); SingleSource.Add("Africa"); SingleSource.Add("Oceania"); ObservableCollection <PropertyModel> enterprise = new ObservableCollection <PropertyModel>(); enterprise.Add(new PropertyModel { Id = 1, Name = "Alibaba" }); enterprise.Add(new PropertyModel { Id = 2, Name = "Tencent" }); enterprise.Add(new PropertyModel { Id = 3, Name = "Baidu" }); enterprise.Add(new PropertyModel { Id = 4, Name = "Huawei" }); enterprise.Add(new PropertyModel { Id = 5, Name = "Wangyi" }); ObservableCollection <PropertyModel> countries = new ObservableCollection <PropertyModel>(); countries.Add(new PropertyModel { Id = 1, Name = "China" }); countries.Add(new PropertyModel { Id = 2, Name = "USA" }); countries.Add(new PropertyModel { Id = 3, Name = "Japan" }); countries.Add(new PropertyModel { Id = 4, Name = "South Korea" }); countries.Add(new PropertyModel { Id = 5, Name = "Russia" }); countries.Add(new PropertyModel { Id = 6, Name = "French" }); countries.Add(new PropertyModel { Id = 7, Name = "Germany" }); TwoSource.Add(new GroupModel { GroupName = "enterprise", Property = enterprise }); TwoSource.Add(new GroupModel { GroupName = "countries", Property = countries }); }