How can i keep selected checkbox items values ?

Ekrem Tapan

10y919.NET

I have a one dropdownlist and checkbox items. How can i make when i keep selected items when change dropdown listitem.

protected void ddlList_SelectedIndexChanged(object sender, EventArgs e)
{
ddlList.AppendDataBoundItems = true;
StringBuilder builder = new StringBuilder();
string sqlQueryOcc = "";
sqlQueryOcc += " select child.CODE,child.TITLE,child.PARENT_CODE,child.YEARS, parent.INDUS_CAT_NAME";
sqlQueryOcc += " from SALARY_INDS_OCCNAME as parent ";
sqlQueryOcc += " inner join dbo.SALARY_INDS_OCCSUBNAME as child ";
sqlQueryOcc += " on parent.INDUS_CAT_CODE = child.PARENT_CODE";
sqlQueryOcc += " where child.PARENT_CODE = '" + ddlList.SelectedValue + "' and child.YEARS = '" + ddlYear.SelectedValue + "'";
sqlQueryOcc += " group by child.CODE,child.TITLE , child.PARENT_CODE ,child.YEARS, parent.INDUS_CAT_NAME";
sqlQueryOcc += " having count(*)>1";
sqlQueryOcc += " order by child.PARENT_CODE asc";
seledItems = ConvertLib.ToStr(Request.Form["sel_items[]"], string.Empty).Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries);
HiddenField1.Value = String.Join(",", seledItems);
using (SqlCommand cmd = new SqlCommand(sqlQueryOcc))
{
cmd.CommandType = CommandType.Text;
cmd.Connection = conn;
conn.Open();
SqlDataAdapter da = new SqlDataAdapter(cmd);
DataTable dt = new DataTable();
da.Fill(dt);
foreach (DataRow row in dt.Rows)
{
builder.AppendFormat("
{1}

, row[

"CODE"

].ToString(), row[

"TITLE"

].ToString(),

this

.IsChecked(row[

"CODE"

].ToString(), seledItems), row[

"PARENT_CODE"

].ToString());

}
conn.Close();
this.occList.Text = builder.ToString();
}
}

For ex: DropdownList first item Fruit, when i was select fruit will be show apple, banana, orange, then i select apple and banana. After selected thats change dropdownlist second item for ex: Computer. then when i was select computer will be show keyboard, monitor, mouse, camera etc. and will be select monitor and keyboard. Then i done this submit this event need to show apple, banana, monitor and keyboard.

how can i make it ?

2 Replies

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Vincent Maverick Durano10y ago
Seems like you are looking for a cascading dropdown. There are many ways to implement it. Here's a server-side example:
privatestringGetConnectionString()
{
//callinguptheconnectionstringthatwassetupfromthewebconfigfile
returnSystem.Configuration.ConfigurationManager.ConnectionStrings["DBConnection"].ConnectionString;
}
privatevoidBindDropDownList1()
{
DataTabledt=newDataTable();
SqlConnectionconnection=newSqlConnection(GetConnectionString());
try
{
connection.Open();
stringsqlStatement="SELECTColumnName*FROMTableName";
SqlCommandsqlCmd=newSqlCommand(sqlStatement,connection);
SqlDataAdaptersqlDa=newSqlDataAdapter(sqlCmd);
sqlDa.Fill(dt);
if(dt.Rows.Count>0)
{
DropDownList1.DataSource=dt;
DropDownList1.DataTextField="ColumnName";//theitemstobedisplayedinthelistitems
DropDownList1.DataValueField="ColumnName";//theidoftheitemsdisplayed
DropDownList1.DataBind();
}
}
catch(System.Data.SqlClient.SqlExceptionex)
{
stringmsg="FetchError:";
msg+=ex.Message;
thrownewException(msg);
}
finally
{
connection.Close();
}
}
privatevoidBindDropDownList2(stringfield)
{
DataTabledt=newDataTable();
SqlConnectionconnection=newSqlConnection(GetConnectionString());
try
{
connection.Open();
stringsqlStatement="SELECT*FROMTableWHEREColumnName=@Value1";
SqlCommandsqlCmd=newSqlCommand(sqlStatement,connection);
sqlCmd.Parameters.AddWithValue("@Value1",field)
SqlDataAdaptersqlDa=newSqlDataAdapter(sqlCmd);
sqlDa.Fill(dt);
if(dt.Rows.Count>0)
{
DropDownList2.DataSource=dt;
DropDownList2.DataTextField="ColumnName";//theitemstobedisplayedinthelistitems
DropDownList2.DataValueField="ColumnName;//theidoftheitemsdisplayed
DropDownList2.DataBind();
}
}
catch(System.Data.SqlClient.SqlExceptionex)
{
stringmsg="FetchError:";
msg+=ex.Message;
thrownewException(msg);
}
finally
{
connection.Close();
}
}
protectedvoidPage_Load(objectsender,EventArgse)
{
if(!IsPostBack)
{
BindDropDownList1();
}
}
protectedvoidDropDownList1_SelectedIndexChanged(objectsender,System.EventArgse)
{
BindDropDownList2(DropDownList1.SelectedItem.Text);
}
You just need to set AutoPostback for your first DropDownList to fire up the selectedindex changed event.
Alternatively, you can use jQuery or AJAXControlToolkit to implement the same:
http://www.mikesdotnetting.com/Article/97/cascading-dropdownlists-with-jquery-and-asp-net
0
Munesh Sharma10y ago
you can use update panel ,
0