Retrieving ComboBox Value through Request.Form

[fightclub777]

Hello,

I have a particular scenario where I need to retrieve the ComboBox Value through a Request.Form method.

For a standard ASP.NET dropdownlist control, the following code returns the selected item value:

Request.Form("DropDownID")

However, with the comboBox, I cannot get the value.  Upon finding the control Key, i see that there are two options:

"ComboBoxID_Input", which returns the Text Value and
"CombboBoxID_ClientState", which returns something like this:

"{"logEntries":[],"value":"1461","text":"5 Business Days","enabled":true}"

Is there a way to extract the value easily, without having to dissect the "clientState" string?

Thank you.

[fightclub777]

no one? :(

[Simon]

Hi fightclub777,

These two fields: "ComboBoxID_Input" and "ComboBoxID_ClientState" contain all additional information of the RadComboBox. The only way to get the value as you require is to parse the client state string. You could use the following approach:

        string clientState = Request.Form[this.RadComboBox1.ClientID + "_ClientState"];

        Regex regex = new Regex(".+\"value\":\"");

        clientState = regex.Replace(clientState, String.Empty);

        regex = new Regex("\",\"text\".+");

        clientState = regex.Replace(clientState, String.Empty);

Finally, in the clientState variable you have the value of the RadComboBox.

I hope this helps.

Kind regards,
Simon
the Telerik team

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[bemara57]

Boy is this ugly.. but it works. Hopefully you guys find a way to make it more standard so I can just do Request.Form[dropDownUniqueID]. Doing it your way added about 20 lines of code for each dropdown value I want to retrieve instead of just a one liner "Request.Form[dropDownUniqueID]". I have to add a static class that stores the UniqueID AND the ClientID, then run some nested if statements to get the value. Here's what I did:

Static class:
        public static string ThemeDropDownUniqueID = String.Empty;
        public static string ThemeDropDownClientID = String.Empty;

On some aspx code behind page:
        if (ThemeProviderCustom.ThemeDropDownUniqueID.Length == 0)
            ThemeProviderCustom.ThemeDropDownUniqueID = themeDropDown.UniqueID;

        if (ThemeProviderCustom.ThemeDropDownClientID.Length == 0)
            ThemeProviderCustom.ThemeDropDownClientID = themeDropDown.ClientID;

On some other base page (need to do this in the PreOnInit because this changes MasterPage):
                if (Request.Form["__EVENTTARGET"] == ThemeProviderCustom.ThemeDropDownUniqueID)                   
                {
                    string clientState = Request.Form[
                        ThemeProviderCustom.ThemeDropDownClientID + "_ClientState"];

                    if (!clientState.IsNullOrEmpty())
                    {                       
                        Regex regex = new Regex(".+\"value\":\"");
                        clientState = regex.Replace(clientState, String.Empty);

                        regex = new Regex("\",\"text\".+");
                        clientState = regex.Replace(clientState, String.Empty);

                        Globals.SiteAdmin.Page.Theme.Layout = clientState;
                    }
                }

So I've encapsulated into a reusable method (just use string.IsNullOrEmpty instead of IsNullOrEmpty()):

        // Request.Form workaround to get value of RadComboBox
        public static string GetRadComboBoxFormValue(string clientID)
        {
            string clientState = HttpContext.Current.Request.Form[
                clientID + "_ClientState"];

            if (!clientState.IsNullOrEmpty())
            {
                Regex regex = new Regex(".+\"value\":\"");
                clientState = regex.Replace(clientState, String.Empty);

                regex = new Regex("\",\"text\".+");
                clientState = regex.Replace(clientState, String.Empty);
            }

            return clientState;
        }

So now I only have to do this: string ddlFormValue = Helpers.GetRadComboBoxFormValue(
                        ThemeProviderCustom.ThemeDropDownClientID);

Hope it alleviates the process a bit for someone as it did for me. Thanks Simon!

[Simon]

Hi bemara57,

Recently, we received a few more questions related to this 'limitation' of RadComboBox. It appears that it would be useful if one could get the Value of the RadComboBox in a more straightforward and standard way.

So, we published a KB article which outlines how the limitation can be overcome in a rather simpler way. You can check out the article here.

I hope you find it useful.

Greetings,
Simon
the Telerik team

Instantly find answers to your questions at the new Telerik Support Center

[Jay]

FYI, the link to this article seems to no longer work.

[fightclub777]

In the newest version of the controls (2008.3.1105.20), the Input control is now rendered with the same ID as the combo box's uniqueID.  So if you're doing a Request.Form to get the text value, simply drop the "_input" from the Request.Form ID, and it'll work just fine.

[Jay]

Holy Ridiculous Response Time!

Sweet, thanks, didn't even realize a new version popped up.  I need to get my head out of this project and come up for air more often!