private void cbxProvince_SelectedIndexChanged(object sender, EventArgs e)
{
AreaInfo provinceAreaInfo = this.cbxProvince.SelectedItem as AreaInfo;
//判断是否 拿到的城市为空
if (provinceAreaInfo == null)
{
return;
}
//根据省的Id获取所有的城市信息
//加载数据库中的所有的省的数据
string connStr = ConfigurationManager.ConnectionStrings["sqlConn"].ConnectionString;
//创建链接对象
using (SqlConnection conn = new SqlConnection(connStr))
{
using (SqlCommand cmd = conn.CreateCommand())
{
conn.Open();//***********8
cmd.CommandText = @"select AreaId, AreaName, AreaPid from [dbo].[AreaFull] where AreaPId=" + provinceAreaInfo.AreaId;
using (SqlDataReader reader = cmd.ExecuteReader())
{
this.cbxCity.Items.Clear();
while (reader.Read())
{
//int AreadId = int.Parse(reader["AreaId"].ToString());
//把表格的数据转换成 对象数据
AreaInfo areaInfo = new AreaInfo();
areaInfo.AreaId = int.Parse(reader["AreaId"].ToString());
areaInfo.AreaName = reader["AreaName"].ToString();
areaInfo.AreaPId = int.Parse(reader["AreaPId"].ToString());
//把省的信息放到 ComboBox中。ComboBox显示信息是 Item对象的ToString（）
this.cbxCity.Items.Add(areaInfo);
}
} //end useing reader
} //end useing cmd
} //en
this.cbxCity.SelectedIndex = 0;
}