how can I store the RadComboBox selected value in C# code?

Question

My RadComboBoxis supposed to drop down and display options for me to select. the options are name but the selected values are numbers corresponding to the ID of the center.

<telerik:RadComboBox DataValueField="OPERATION_CENTER_ID" RenderingMode="Full" EmptyMessage="Select Operation Center" DataTextField="OPERATION_CENTER_NAME" ID="RadComboBox1" runat="server"></telerik:RadComboBox>

 protected void rdOrders_NeedDataSource(object sender, Telerik.Web.UI.GridNeedDataSourceEventArgs e) {
     //Get OPERATION_CENTER_ID in f1 from f2 query (it is an int)

     string f2 = "select * from [dbo].[GetOperationCentersInfo]('F')";

     SQLHelper a = new SQLHelper(SQLHelper.ConnectionStrings.EmallShippingConnectionString);

       int ID = RadComboBox1.SelectedValue; {
       string f1 = "select * from [dbo].[GetReadyDeliveryOrderItems](" + ID + ")";
       DataTable DataTable1 = a.getQueryResult(f1); //Orders Query by OPERATION_CENTER_ID
       DataTable DataTable2 = a.getQueryResult(f2); //Operation centers Query
       DataTable testDataTable = new DataTable();
       rdOrders.DataSource = DataTable1;
       RadComboBox1.DataSource = DataTable2;

       RadComboBox1.DataBind();
     }

Basically when the user selects a value from RadComboBox1, I want to store that value in an int variable.

are you sure that SelectedValue is an int? what was its value under debug? — BugFinder, Jul 19 '16 at 08:02
I'm trying to save the selectedValue as an integer that's my problem, it's of type string because when I tried directly saving the selectedValue in an int variable it said "cannot implicitly convert type string to int — ytba92, Jul 19 '16 at 09:06
that didnt answer my question at all.. what is the value in "selectedvalue" ?? debug it, look at it, show it here — BugFinder, Jul 19 '16 at 09:07
But the problem is when I put the statement if (radComboBox1.selectedValue == null), it skips the if statement. How can I make it wait for me to select a value and then do the processing? — ytba92, Jul 19 '16 at 09:11
You've provided next to nothing on what you're actually doing, so it would only be speculation - but, if you're getting this when it first opens.. it should skip the if statements!! then, set the values.. it will change.. etc — BugFinder, Jul 19 '16 at 09:31
If you need any more additional information please let me know, the page isn't even loading for me to be able to select statements — ytba92, Jul 19 '16 at 09:40
Ive just explained what to do.. Im not you're mother, Im not going to be doing it for you — BugFinder, Jul 19 '16 at 09:45

score 0 · Accepted Answer · answered Jul 19 '16 at 08:11

Hope that DataValueField is assigned while binding the grid, and the Value is convertible to an integer. Then I would like to suggest int.TryParse for this conversion, So that you use its return value to check whether the conversion is successful or not. See the code below:

int ID;
if(Int32.TryParse(RadComboBox1.SelectedValue,out ID))
{
  // You can proceed with ID 
}
else
{
  // Conversion failed
}

score 0 · Answer 2 · answered Jul 19 '16 at 10:04

Is there any particular reason that you have to data-bind your RadComboBox control in a NeedDataSource event? This will not guarantee that your RadComboBox control will be loaded correctly due to the life cycle of your page/control.

What you possibly can do is to add your data-binding code to Page_Load event, something like below.

protected void Page_Load(object sender, EventArgs e)
{
   if (!IsPostBack)
   {
      BindRadComboBox();
   }
}

private void BindRadComboBox()
{
    string f2 = "select * from [dbo].[GetOperationCentersInfo]('F')";

     SQLHelper a = new SQLHelper(SQLHelper.ConnectionStrings.EmallShippingConnectionString);

       int ID = RadComboBox1.SelectedValue; {
       string f1 = "select * from [dbo].[GetReadyDeliveryOrderItems](" + ID + ")";
       DataTable DataTable1 = a.getQueryResult(f1); //Orders Query by OPERATION_CENTER_ID
       DataTable DataTable2 = a.getQueryResult(f2); //Operation centers Query
       DataTable testDataTable = new DataTable();
       rdOrders.DataSource = DataTable1;
       RadComboBox1.DataSource = DataTable2;
       RadComboBox1.DataBind();
}

You will need to double check the code that fetches the data though. Also for converting string to integer, please refer to un-lucky's answer, which is recommended way of doing it.

Hope this helps.

how can I store the RadComboBox selected value in C# code?

2 Answers2