Button in a column - Creates a null reference exception in prerender

beyti77 — Fri, 06 Apr 2012 15:42:25 GMT

I have a button in a webgrid as a column and its code like below:

<ISWebGrid:WebGridColumn runat="server" Bound="False" ButtonAutoPostback="true" 
 Width="40px" EditType="NoEdit" ButtonText="qweqwe" DataMember="Id" DefaultValue="0"
 ButtonImage="/Style/Images/tick.png"  ColumnType="ButtonImage" NewRowEditType="NoEdit" 
 ButtonPostbackMode="OnTheFly" Name="Id"></ISWebGrid:WebGridColumn>

As you can see, I've tried all I can think of but none of them helped me.

Problem is, when I create a new item in the grid; the item is created successfully but after the creation; a pop-up screen appears and says a null reference exception is occured in the data binding to the webgrid.

When I remove the column, everything is ok.

And when I don't remove the column, eventhough it says a null ref exception is occured; after a refreshing the screen; I can see the item is created successfully and including the newly created item, every item is bind into the webgrid.

I would love if anybody could diect me into the right direction.

Thanks.

Info: The binding and the creation is by default and no override is included and linqdatasource is used for the data and given as a DataSourceId="dsSomething" in ascx page.

WebGrid crashes when scrolling with column freeze and setting a column hidden

Eric — Fri, 08 Jan 2010 08:43:18 GMT

I experience that WebGrid crashes, when the user horizontally scrolls. This happens only when I set the first column to be frozen. It also only happens when I set some columns to hidden (Visible=false).

Attached is a simple sample in VB.NET for that (remove the .txt in the file names). Simplified, the sample contains:

An aspx file with the WebGrid "grdResult" and the columns "Description", "X1", "X2",..."X9"
<FreezePaneSettings AbsoluteScrolling="true" ActiveFrozenColumns="1" MaxFrozenColumns="1" ShowSplitterLine="False" />
In the aspx.vb code file there is a handler for InitializeDataSource which adds some static data to show, so that the grid is not empty
In the handler PreRender I change some column titles (from X1 to C1 etc.) and set two columns to Visible=False

When scrolling, it crashes with: "Microsoft JScript runtime error: 'parentElement' is null or not an object" (Break/Continue/Ignore). The debugger then stands on this JScript code: "var v1d119 =vfcb75.parentElement" (and vfcb75 is null).

I believe this is a bug in WebGrid. We are using the newest WebGrid 6.0.7200.218 and Framework 3.0.5000.705 and the users use Internet Explorer 6 to browse the page.

Can you confirm that this is a bug? If yes, will there be a hotfix available soon? Is there any workaround except not to use freezing or hiding?

Intersoft Community - PreRender

Button in a column - Creates a null reference exception in prerender

WebGrid crashes when scrolling with column freeze and setting a column hidden