What is the CORRECT way to handle null values in a RadGrid Column...

[mark baer]

I am using WCF Dataservices so I have hierarchical data...Some of my values are coming back with null and I am getting "Input String was not in a correct format"...I am trying to handle the null values in the radgrid_ItemDatabound, but I am still having problems...How SHOULD I be handling null values in the radgrid column. 

RadGrid HTML:

<telerik:RadGrid ID="radgridCredits" runat="server"
AllowFilteringByColumn="True"<BR>
AllowPaging="True" AllowSorting="True" AutoGenerateColumns="False"
CellSpacing="0"<BR>
GridLines="None" Height="270px"
OnNeedDataSource="radgridCredits_NeedDataSource"<BR>
OnSelectedIndexChanged="radgridCredits_SelectedIndexChanged"
OnItemDataBound="radgridCredits_ItemDatabound" PageSize="100"
ShowGroupPanel="True"<BR>
Visible="False"
Width="100%"><BR>
<ClientSettings
AllowDragToGroup="True"><BR>
<Scrolling AllowScroll="True" UseStaticHeaders="True"
/><BR>
</ClientSettings><BR>
<MasterTableView><BR>
<CommandItemSettings ExportToPdfText="Export to Pdf"
/><BR>
<Columns><BR>
<telerik:GridButtonColumn CommandName="Select" DataTextField="Show.Title"
FilterControlAltText="Filter column2
column"<BR>
HeaderText="Show" SortExpression="Show.Title"
UniqueName="column2"><BR>
<HeaderStyle Width="25%"
/><BR>
<ItemStyle Width="25%" VerticalAlign="Top"
/><BR>
</telerik:GridButtonColumn><BR>
<telerik:GridBoundColumn DataField="Show.Medium.name"
FilterControlAltText="Filter TalentColumn
column"<BR>
FilterControlWidth="50px" HeaderText="Media"
SortExpression="Show.Medium.name"<BR>
UniqueName="TalentColumn"><BR>
<HeaderStyle Width="9%"
/><BR>
<ItemStyle VerticalAlign="Top" Width="9%"
/><BR>
</telerik:GridBoundColumn><BR>
<telerik:GridBoundColumn DataField="Craft.name" FilterControlAltText="Filter
column1
column"<BR>
FilterControlWidth="75px" HeaderText="Craft" SortExpression="Craft.name"
UniqueName="column1"><BR>
<HeaderStyle Width="15%"
/><BR>
<ItemStyle Width="15%" VerticalAlign="Top"
/><BR>
</telerik:GridBoundColumn><BR>
<telerik:GridBoundColumn DataField="Show.Project.us_bor"
DataFormatString="${C:0}" FilterControlAltText="Box
Office"<BR>
FilterControlWidth="50px" HeaderText="US BO(US$)"
SortExpression="Show.Project.us_bor"<BR>
UniqueName="colBoxOffice"><BR>
<HeaderStyle Width="8%"
/><BR>
<ItemStyle Width="8%" VerticalAlign="Top"
/><BR>
</telerik:GridBoundColumn><BR>
<telerik:GridBoundColumn DataField="Show.Project.ProdHouse.name"
FilterControlAltText="Filter column3
column"<BR>
HeaderText="Production House" SortExpression="Show.Project.ProdHouse.name"
UniqueName="column3"><BR>
<HeaderStyle Width="12%"
/><BR>
<ItemStyle Width="12%" VerticalAlign="Top"
/><BR>
</telerik:GridBoundColumn><BR>
<telerik:GridBoundColumn DataField="comment" FilterControlAltText="Filter
column4
column"<BR>
HeaderText="Comment" SortExpression="comment"
UniqueName="colComment"><BR>
<HeaderStyle Width="22%"
/><BR>
<ItemStyle Width="22%" VerticalAlign="Top"
/><BR>
</telerik:GridBoundColumn><BR>
<telerik:GridBoundColumn DataField="Show.year" FilterControlAltText="Filter
column5
column"<BR>
FilterControlWidth="40px" HeaderText="Year" SortExpression="Show.year"
UniqueName="column5"><BR>
<ItemStyle VerticalAlign="Top"
/><BR>
</telerik:GridBoundColumn><BR>
</Columns><BR>
<EditFormSettings><BR>
<EditColumn FilterControlAltText="Filter EditCommandColumn
column"><BR>
</EditColumn><BR>
</EditFormSettings><BR>
</MasterTableView><BR>
<FilterMenu
EnableImageSprites="False"><BR>
</FilterMenu><BR>
<HeaderContextMenu CssClass="GridContextMenu
GridContextMenu_Default"><BR>
</HeaderContextMenu><BR>
</telerik:RadGrid>

Here is my item databound event...

<P> protected void radgridCredits_ItemDatabound(object sender,
GridItemEventArgs e)<BR>
{<BR>
try<BR>
{<BR>
if ((e.Item.ItemType == Telerik.Web.UI.GridItemType.Item)
||<BR>
(e.Item.ItemType ==
Telerik.Web.UI.GridItemType.AlternatingItem))<BR>
{<BR>
if (e.Item is
GridDataItem)<BR>
{<BR>
GridDataItem gridDataItem =
(GridDataItem)e.Item;<BR>
Credit credit = (Credit)(e.Item.DataItem);</P>
<P>
if (!credit.Show.title.ToLower().Contains("select a
talent"))<BR>
{<BR>
if (credit.comment ==
null)<BR>
{<BR>
gridDataItem["colComment"].Text =
"";<BR>
}<BR>
if (credit.Show.Project.us_bor ==
null)<BR>
{<BR>
gridDataItem["colBoxOffice"].Text =
"";<BR>
}<BR>
}<BR>
}  </P>
<P>
// Telerik.Web.UI.GridDataItem item = e.Item as
Telerik.Web.UI.GridDataItem;<BR>
//Credit credit =
(Credit)e.Item.DataItem;<BR>
//if
(credit.comment==null)<BR>
//{<BR>
//    credit.comment =
"";<BR>
//}<BR>
//if (credit.Show.Project.us_bor ==
null)<BR>
//{<BR>
//    credit.Show.Project.us_bor =
0m;<BR>
//}<BR>
//Get the "colDivision" cell value using the columnUniqueName.
<BR>
//if (item["comment"].Text ==
null)<BR>
//{<BR>
//    item["comment"].Text =
"";<BR>
//}<BR>
}
<BR>
<BR>
}<BR>            catch
(Exception
ex)<BR>
{<BR>
SiteMaster masterPage =
(SiteMaster)Page.Master;<BR>
masterPage.SetAlertMessage("Error fetching Talent Credits:  " +
ex.Message);<BR>
return;<BR>
}<BR>        }</P><BR>

[Marin]

Hello,

 Normally the grid can handle null value in the columns. The problem might be due to the fact that you are binding to properties of nested objects (Show.Project.ProdHouse.name, Show.Project.us_bor etc.) So if any of those nested objects are null an exception might be thrown. You should make sure that you always bind to objects that have non-null values for the nested objects in order to access the most inner property. For example you might filter the null records before passing them to a datasource for the grid. Otherwise if for example Project is null the grid will try to access Show.Project.us_bor which will cause an exception.

Best wishes,
Marin
the Telerik team