When accesing/assigning control in Datalist using FindControl, Im getting: System.NullReferenceException: Object reference not set to an instance of an object.

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Im doing it like this:

XML

<asp:DataList ID="DataList" runat="server" RepeatDirection="Horizontal"
                                        Width="600px" CellPadding="5" CellSpacing="5">


                                        <ItemTemplate>
                                            <asp:Image ID="Image1" runat="server" />
                                        </ItemTemplate>
                                    </asp:DataList>

and code behind is:

Image img = (Image)DataList.FindControl("Image1");
img.ImgUrl = a.ImagePath

Im getting same error even when using Label control or other control

Any idea ?

Posted 11-Nov-12 8:41am

Maho^^^

Updated 11-Nov-12 8:56am

v2

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Himanshu Yadav 11-Nov-12 22:51pm

Are you able to see path in grid.Your column is not filling with value thats why is giving exception when you trying to read the value.

Sergey Alexandrovich Kryukov 11-Nov-12 23:38pm

In what line the exception is thrown? It that "img.ImgUrl = a.ImagePath"?
Then the problem is that FindControl returns null, and you are trying to dereference the result.
--SA

Maho^^^ 12-Nov-12 15:20pm

yes, exception thrown exactly at "img.ImgUrl = a.ImagePath"

Sergey Alexandrovich Kryukov 12-Nov-12 16:26pm

"img" or "a" is null. Check up under the debugger, that's it.
--SA

Maho^^^ 23-Nov-12 11:15am

tnx it helped me.

Sergey Alexandrovich Kryukov 23-Nov-12 11:51am

My pleasure.
--SA

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Ram424 · Answer 1 · 2012-11-11T17:49:00

Solution 2

Label ramImage=(Label)e.Item.FindControl("lblno1");

Posted 11-Nov-12 17:49pm

Ram424

mohitjain1943 · Answer 2 · 2012-11-11T17:04:00

Solution 1

In backend use this code

Label lblno = (Label)e.Item.FindControl("lblno1");

to find out your controls.....:)

Posted 11-Nov-12 17:04pm

mohitjain1943

Comments

Maho^^^ 12-Nov-12 15:33pm

yes I have tried that ... but I think e.Item or something like that is used for handling evants, I just want to access <asp:Image control and to add ImageUrl to it which is just a string value