RadGrid and Entity Framework in Code-behind

[Gonzalo]

Hi dear friends!

Do you have a sample of asp.net webforms page populating a radgrid with entity framework objects in code behind. Example:

    public partial class _Default : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            ClientsContext db = new ClientsContext();
            var query = from b in db.Clients orderby b.LastName select new { Client = b.ClientId, First = b.FirstName, Last = b.LastName, County = b.CountyName, City = b.City };
            GridView1.DataSource = query.ToList().Take(100);
        }
    }
}

Your support will be greatly appreciated.

G 

[Daniel]

Hello Gonzalo,

I believe the following demo will give you a good starting point:

• Entity Framework Manual Operations

Best regards,
Daniel
the Telerik team

[Gonzalo]

Thanks Daniel. I will check this out.

[Al]

Hi Daniel,

I believe there is an error in the C# code listed in your link, it shows:

protected void RadGrid1_NeedDataSource(object source, GridNeedDataSourceEventArgs e)
{
    var result = from r in DbContext.Products
                         select r;
    RadGrid1.DataSource = result;
}

But that gives errors, should it not be:

protected void RadGrid1_NeedDataSource(object source, GridNeedDataSourceEventArgs e)
{
    var result = from r in DbContext.Products
                         select r;

    RadGrid1.DataSource = result.toList();

}

​

[Kostadin]

Hi Al,

Know that this is the exact code which is used for creating the demo. I am not sure why the code throws an error on your side without replicating the issue locally. Could you please provide your an image of the exception that you have received and also your code declaration?

Regards,
Kostadin
Telerik

 

 

[Al]

Hi Kostadin,

Please see the attached pic and code below.

<telerik:RadGrid ID="grdMain" runat="server" AllowFilteringByColumn="True" AllowSorting="True"
    AutoGenerateDeleteColumn="false" AutoGenerateEditColumn="false"
    ShowGroupPanel="True" OnNeedDataSource="grdMain_NeedDataSource" OnPreRender="grdMain_PreRender" OnItemDataBound="grdMain_ItemDataBound"
    OnDeleteCommand="grdMain_DeleteCommand" AutoGenerateColumns="true" >
    <ClientSettings AllowDragToGroup="True">
        <ClientEvents OnCommand="grdMain_OnCommand" />
    </ClientSettings>
    <MasterTableView CommandItemDisplay="Top" EditMode="PopUp" >
        <RowIndicatorColumn Visible="False">
        </RowIndicatorColumn>
        <ExpandCollapseColumn Created="True">
        </ExpandCollapseColumn>
        <Columns>
            <telerik:GridButtonColumn CommandName="Edit" UniqueName="Edit" Text="Edit" ItemStyle-Width="30px"></telerik:GridButtonColumn>
            <telerik:GridButtonColumn CommandName="Delete" UniqueName="Delete" Text="Delete" ConfirmDialogType="RadWindow" ConfirmText="Continue to delete?" ItemStyle-Width="30px"></telerik:GridButtonColumn>
            <telerik:GridButtonColumn CommandName="Groups" UniqueName="Groups" Text="Groups" ItemStyle-Width="30px"></telerik:GridButtonColumn>
            <telerik:GridButtonColumn CommandName="Rights" UniqueName="Rights" Text="Rights" ItemStyle-Width="30px"></telerik:GridButtonColumn>
            <telerik:GridButtonColumn CommandName="AD_Paths" UniqueName="AD_Paths" Text="AD_Paths" ItemStyle-Width="60px"></telerik:GridButtonColumn>
        </Columns>
    </MasterTableView>
</telerik:RadGrid>

​

[Kostadin]

Hello Al,

Could you please provide your code behind since I am still not able to replicate the issue that you are facing? Additionally which version of RadControls you are using?

Regards,
Kostadin
Telerik

 

 

[Al]

Hi Kostadin,

I did post my code-behind previously, nothing fancy there. In NeedDataSource I am using :

var result = from r in DbContext.Products
                     select r;
RadGrid1.DataSource = result.ToList();

If I don't use add ToList() then I get the error. I am using version  2014.3.1209.45

[Kostadin]

Hello Al,

I isolate the example from the demos in a small runnable sample. As you can see there is no need to call ToList of the result. Could you please verify that you are using exactly the same entity model? If you are using a different one you might return a different type of data that requires to call toList as the exception notes.

Regards,
Kostadin
Telerik