省级三联动

最新推荐文章于 2019-07-16 14:01:39 发布

最新推荐文章于 2019-07-16 14:01:39 发布 · 109 阅读

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本文介绍了一个基于ASP.NET的省市县三级联动下拉框实现方案，通过使用C#和SQL Server数据库交互来动态填充不同级别的地区信息。首先加载省份信息到第一个下拉框中，当省份选择发生变化时，会触发事件加载对应的城市列表；同样地，当城市选择变化时，将加载相应的县区列表。

public partial class 省市县三级联动 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
Download();
}

}
string constr = "data source=.;initial catalog=liandong;user id=sa;pwd=7777777";

protected void Download()
{

SqlConnection conn = new SqlConnection(constr);
conn.Open();
SqlCommand cmd = new SqlCommand();
cmd.Connection = conn;
cmd.CommandText = "select proID,proName from T_Promary";
SqlDataAdapter adapter = new SqlDataAdapter(cmd);
DataTable dt=new DataTable();
adapter.Fill(dt);
DropDownList1.DataSource = dt;
DropDownList1.DataTextField = "proName";
DropDownList1.DataValueField = "proId";
DropDownList1.DataBind();

cmd.Dispose();
conn.Dispose();

}
string tiaojian1 = string.Empty;
string tiaojian2 = string.Empty;
protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{
tiaojian1 = DropDownList1.SelectedValue;
SqlConnection conn = new SqlConnection(constr);
conn.Open();
SqlCommand cmd = new SqlCommand();
cmd.Connection = conn;
cmd.CommandText = "select cityID,cityName from T_City where proID=@tiaojian1 ";
cmd.Parameters.AddWithValue("@tiaojian1", tiaojian1);
SqlDataAdapter adapter = new SqlDataAdapter(cmd);
DataTable dat = new DataTable();
adapter.Fill(dat);
DropDownList2.DataSource = dat;
DropDownList2.DataTextField = "cityName";
DropDownList2.DataValueField = "cityID";
DropDownList2.DataBind();
cmd.Dispose();
conn.Dispose();
}

protected void DropDownList2_SelectedIndexChanged(object sender, EventArgs e)
{
tiaojian2 = DropDownList2.SelectedValue;
SqlConnection conn = new SqlConnection(constr);
conn.Open();
SqlCommand cmd = new SqlCommand();
cmd.Connection = conn;
cmd.CommandText = "select ctiyid,countyname,countyid from county where ctiyid=@tiaojian2 ";
cmd.Parameters.AddWithValue("@tiaojian2", tiaojian2);
SqlDataAdapter adapter = new SqlDataAdapter(cmd);
DataTable data = new DataTable();
adapter.Fill(data);
DropDownList3.DataSource = data;
DropDownList3.DataTextField = "countyname";
DropDownList3.DataValueField = "countyid";
DropDownList3.DataBind();
cmd.Dispose();
conn.Dispose();
}
}
}