private void LoadProvince()
{
/*throw new NotImplementedException();*/
//1.查询所有父ID为0的那些数据
string sql = "select Areaid,AreaName from TblArea where AreaPid=@pid";
SqlParameter pl = new SqlParameter("@pid", SqlDbType.Int)
{
Value = 0
};
using (SqlDataReader reader = SqlHelper.ExecuteReader(sql, pl))
{
if (reader.HasRows)
{
while (reader.Read())
{
TblArea model = new TblArea();
model.AreaID = reader.GetInt32(0);
model.AreaName = reader.GetString(1);
comboBox1.Items.Add(model);//会调用TblArea类的ToString方法，所有需要重载此方法
}
}
}
}
private void button1_Click(object sender, EventArgs e)
{
if (comboBox1.SelectedItem != null)
{
TblArea model = comboBox1.SelectedItem as TblArea;//因为上文中添加的信息即为TblArea类型的
MessageBox.Show(model.AreaName + " " + model.AreaID);
}
}
//选择项改变事件
private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
{
//获取省份id
if (comboBox1.SelectedItem != null)
{
//comboBox3.Items.Clear();//每次清空数据
TblArea model = comboBox1.SelectedItem as TblArea;
int areaid = model.AreaID;
//2.根据areaid从数据库中查询对应的数据
List <TblArea> cities = GetSubCity(areaid);
//方式1
// foreach(TblArea item in cities)
// {
// comboBox3.Items.Add(item);
// }
//方式2 通过数据绑定技术向下拉菜单中增加选项
//建议绑定数据源的时候先设置DisplayMember和ValueMember的值
//再设置DataSource的数据源
comboBox3.DisplayMember = "AreaName";
comboBox3.ValueMember = "AreaID";
comboBox3.DataSource = cities;
}
}
//根据父id查询子城市
private List <TblArea> GetAreaByParentId(int pid)
{
List <TblArea> list = new List <TblArea>();
string sql = "select Areaid,AreaName from TblArea where AreaPid=@pid";
SqlParameter pl = new SqlParameter("@pid", SqlDbType.Int)
{
Value = pid
};
using (SqlDataReader reader = SqlHelper.ExecuteReader(sql, pl))
{
if (reader.HasRows)
{
while (reader.Read())
{
TblArea model = new TblArea();
model.AreaID = reader.GetInt32(0);
model.AreaName = reader.GetString(1);
list.Add(model);
}
}
}
return(list);
}