RadComboBox / Label in GridTemplate

[ManniAT]

Requirements
RadControls version	2009.Q2
.NET version	3.5
Visual Studio version	2008
programming language	C#
browser support	all browsers supported by RadControls

PROJECT DESCRIPTION
@Telerik: I used the dll from RadControls_for_ASP.NET_AJAX_2009_2_701_trial_hotfix.zip - but I get no trial messages. Could you please check if the DLL is really the trial version.

Assume a (common) scenario where a column of a GridRow references a different table - the "master table" holds an ID and the related table this ID and some "Name" for it.
A typical use for a GridDropDownColumn.

But sometimes I came to a point where I couldn't use a GridDropDownColum - this happened when I had to do "very special customizations".
At this time I had to use a GridTemplateColumn. For the EditItemTemplate this is no problem - simply use a RadComboBox.
But how about the ItemTemplate?
One solution is to use a RadComboBox again - but the User should not be able to change a selection (this could confuse him).
To set the RadComboBox to Enabled="false" is also not really a solution - the thing is almost impossible to read.
Another approach is to define a datasource which allows to select the "Name" by giving an ID or to get the master data from some kind of join - which could make problems if you want to update the data.
Often I use "cached data" for things like "Country, Status, Region, Role...) - so the data is there - and I can access it very fast.
And last not least - I want to do it "the easy way" - no code behind for every grid which holds such a column.

The idea - I want to have a kind of Label which acts exactly like a ComboBox - I have a datasource(id), a selected value and so on.
As a result I get the same as with a ComboBox - but not a "unreadable" disabled thing - I just get a label (some kind of static text).
In simple words - I get the same result as with a GridDropDownColumn - but with full customization capabilities.

I built such a control (rough done -- Css class and other attributes are not rendered) and here it is.
The use is almost identical to a RadComboBox - here an example for a templated column using this control.

<telerik:GridTemplateColumn DataField="FunctionID" DataType="System.Int32" HeaderText="Function" SortExpression="FunctionID" UniqueName="FunctionID">
    <ItemTemplate>
        <cc1:ComboLabel runat="server" DataTextField="FunctionName" DataValueField="FunctionID" DataSourceID="odsTestFunctions" SelectedValue='<%# Eval("FunctionID") %>' />
        &nbsp;&nbsp;(<%# (string)((int)Eval("FunctionID")<2 ? "<b style='color:red;'>Handle with care</b>" : "Teasing enabled") %>)
    </ItemTemplate>
    <EditItemTemplate>
        <telerik:RadComboBox ID="cbFunctionID" runat="server" DataTextField="FunctionName" DataValueField="FunctionID" DataSourceID="odsTestFunctions" SelectedValue='<%# Bind("FunctionID") %>' />
    </EditItemTemplate>
</telerik:GridTemplateColumn>

You can see - both controls are almost identical - I set exactly the same values for
DataTextField, DataValueField, DataSourceID and SelectedValue

I use this control very often - and hope it is useful for you also.
To enhance the thing (more render capabilities) just change the function Render in ComboLabel (last function at the end).

Kind Regards

Manfred

[Yavor]

Hello ManniAT,

Since the use of the controls and the approach is somewhat specific, it is not very suitable for a code library project. Nevertheless, I have posted this sample as a forum post, so that other users can benefit from it as well.
Additionally, I have updated your Telerik points for your involvement!

Best wishes,
Yavor
the Telerik team

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Check out the tips for optimizing your support resource searches.

[ManniAT]

Hi Yavor,

if you think this solution is "to specific" - no problem.
If the code is here or at the library makes no big difference - if someone has the same need as I - he can get it from here also.

A little followup for the code.
The rendering of extra attributes (back-color, CssClass and so on) works like this:

AFTER THIS LINE ADD THE CODE: Label lblOut = new Label();
foreach (string key in Attributes.Keys) {
    lblOut.Attributes[key] = Attributes[key];
}
if (ControlStyleCreated) {
    lblOut.ApplyStyle(ControlStyle);
}

Just add this code in the render function of the control - that's it.

Regards

Manfred

[Yavor]

Hello Manfred ,

Thank you for the additional code.
I am sure it will be useful for the community.

Kind regards,
Yavor
the Telerik team

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