Copy Code code as follows:
if (! IsPostBack)
{
First level Category List
This. Dropdownlist1.datasource = DSBB. SelectSubjct1 ();
This. Dropdownlist1.datatextfield = "CName";
This. Dropdownlist1.datavaluefield = "Ccode";
This. Dropdownlist1.databind ();
This. DropDownList1.Items.Insert (0,new ListItem ("Please Select First class category", "0"));
This. DropDownList8.Items.Insert (0, New ListItem ("Please select Class two", "0"));
This. DropDownList9.Items.Insert (0,new ListItem ("Please select Class three", "0"));
Level two Category List
}
<summary>
Binding Level Two classification
</summary>
<param name= "Sender" ></param>
<param name= "E" ></param>
protected void DropDownList1_SelectedIndexChanged (object sender, EventArgs e)
{
Libs. Database.dbbase DBB = new libs. Database.dbbase ();
If Convert.ToInt32 (this. Dropdownlist1.selectedvalue) = = 0)//Clear list content
{
This. DropDownList8.Items.Clear ();
This. DropDownList8.Items.Insert (0, New ListItem ("Please select Class two", "0"));
This. DropDownList9.Items.Clear ();
This. DropDownList9.Items.Insert (0, New ListItem ("Please select Class three", "0"));
}
else//Level two category list
{
This. Dropdownlist8.datasource = DBB. Selectsubjct2 (this. DropDownList1.SelectedValue.Substring (0,2));
This. Dropdownlist8.datatextfield = "CName";
This. Dropdownlist8.datavaluefield = "Ccode";
This. Dropdownlist8.databind ();
This. DropDownList8.Items.Insert (0,new ListItem ("Please select Class two", "0"));
This. DropDownList9.Items.Clear ()//Purge third category
This. DropDownList9.Items.Insert (0, New ListItem ("Please select Class three", "0"));
}
}
<summary>
Binding Level Three classification
</summary>
<param name= "Sender" ></param>
<param name= "E" ></param>
protected void Dropdownlist8_selectedindexchanged (object sender, EventArgs e)
{
Libs. Database.dbbase dbase = new libs. Database.dbbase ();
This. Dropdownlist9.datasource = Dbase.selectsubject3 (this. DropDownList8.SelectedValue.Substring (0,4));
This. Dropdownlist9.datatextfield = "CName";
This. Dropdownlist9.datavaluefield = "Ccode";
This. Dropdownlist9.databind ();
This. DropDownList9.Items.Insert (0,new ListItem ("Please select Class three", "0"));
}
Dbbase.cs page:
Copy Code code as follows:
<summary>
Query First Level column
</summary>
<returns></returns>
Public DataSet SelectSubjct1 ()
{
String con = system.configuration.configurationsettings.appsettings["sqlconn"];
SqlConnection conn = new SqlConnection (Con);
String sqlstr = "Select Kndid, Ccode, CName, clevel from kind WHERE clevel = 1";
DataSet DST = new DataSet ();
SqlDataAdapter SDA = new SqlDataAdapter (Sqlstr,conn);
Try
{
Sda. Fill (DST);
return DST;
}
catch (Exception ex)
{
throw new Exception (ex. message);
}
Finally
{
Conn. Close ();
}
}
<summary>
Query level two column content
</summary>
<param name= "Ccode" ></param>
<returns></returns>
Public DataSet Selectsubjct2 (string ccode)
{
String conn1 = system.configuration.configurationsettings.appsettings["Sqlconn"];
SqlConnection conn = new SqlConnection (CONN1);
String sqqq = "Select Kndid,ccode,cname,clevel from kind where clevel = 2 and ccode like '" + ccode + "%";
DataSet DSS = new DataSet ();
SqlDataAdapter SDD = new SqlDataAdapter (Sqqq,conn);
Try
{
Sdd. Fill (DSS);
return DSS;
}
catch (Exception ex)
{
throw new Exception (ex. message);
}
Finally
{
Conn. Close ();
}
}
<summary>
Query level three column content
</summary>
<param name= "CDE" ></param>
<returns></returns>
Public DataSet selectsubject3 (string cde)
{
String conn2 = system.configuration.configurationsettings.appsettings["Sqlconn"];
SqlConnection conn = new SqlConnection (CONN2);
String sqq = "Select Kndid,ccode,cname,clevel from Kind where clevel = 3 and ccode like '" + CDE + "%";
DataSet DST = new DataSet ();
SqlDataAdapter sdaa = new SqlDataAdapter (Sqq,conn);
Try
{
Sdaa. Fill (DST);
return DST;
}
catch (Exception ex)
{
throw new Exception (ex. message);
}
Finally
{
Conn. Close ();
}
}
Note: dropdownlist1_selectedindexchanged event, autopostback= "True"
