private async void ProvinceComboBox_SelectionChanged(object sender, SelectionChangedEventArgs e) { EnProvince province = this.ProvinceComboBox.SelectedItem as EnProvince; this.AreaComboBox.ItemsSource = await QueryAreaFromDBAsync(province.ID); this.AreaComboBox.SelectedIndex = 0; //选择省份后给他填充所有城市的第一个 }
/// <summary> /// 通过异步方法获取所有省信息 /// </summary> /// <returns></returns> private static async Task <List <EnProvince> > QueryProvinceFromDBAsync() { List <EnProvince> provinces = new List <EnProvince>(); EnProvince province; string sql = "select * from Province"; DataSet ds = db.ReturnDataSet(sql); DataTable dt = ds.Tables[0]; for (int i = 0; i < dt.Rows.Count; i++) { province = new EnProvince(); province.ID = int.Parse(dt.Rows[i]["ID"].ToString()); province.ProvinceCode = dt.Rows[i]["ProvinceCode"].ToString(); province.ProvinceName = dt.Rows[i]["ProvinceName"].ToString(); provinces.Add(province); } return(provinces); }