//显示当前选中的省份的名称和ID
private void button1_Click(object sender, EventArgs e)
{
//if (comboBox1.Text.Trim().Length > 0)
//{
// comboBox1.SelectedItem
//}
if (comboBox1.SelectedItem != null)
{
TblArea model = comboBox1.SelectedItem as TblArea;
MessageBox.Show(model.AreaName + " " + model.AreaID);
}
}
private void LoadProvince()
{
//1.查询所有父ID为0的那些数据
string sql = "select areaname,areaid from TblArea where areapid=@pid";
SqlParameter p1 = new SqlParameter("@pid", SqlDbType.Int)
{
Value = 0
};
using (SqlDataReader reader = SQLHelper.ExecuteReader(sql, p1))
{
if (reader.HasRows)
{
while (reader.Read())
{
TblArea model = new TblArea();
model.AreaID = reader.GetInt32(1);
model.AreaName = reader.GetString(0);
comboBox1.Items.Add(model);
}
}
}
}
private List <TblArea> GetAreaByParentId(int pid)
{
List <TblArea> list = new List <TblArea>();
string sql = "Select AreaID,AreaName from TblArea where AreaPId=@id";
SqlParameter p1 = new SqlParameter("@id", SqlDbType.Int)
{
Value = pid
};
using (SqlDataReader reader = SQLHelper.ExecuteReader(sql, p1))
{
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);
}
//选择项改变事件
private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
{
//1.获取当前用户选择的省份ID
if (comboBox1.SelectedItem != null)
{
TblArea model = comboBox1.SelectedItem as TblArea;
int areaId = model.AreaID;
//2.根据areaId从数据库中查询对应的id
List <TblArea> cities = GetSubCity(areaId);
//方式一：向下拉菜单中增加数据(需要加comboBox2.Items.Clear();命令)
//foreach (TblArea item in cities)
//{
// comboBox2.Items.Add(item);
//}
//方式二：通过数据绑定的方式向下拉菜单中增加项（不需要情况items）
//建议绑定数据源的时候，先设置DisplayMember和ValueMember的值。先告诉下拉菜单，这样数据源一绑好就会立刻显示。
//然后再设置DataSource数据源对象
comboBox2.DisplayMember = "AreaName"; //看见的是哪个
comboBox2.ValueMember = "AreaID"; //对应的Id是多少
comboBox2.DataSource = cities;
}
}
