using an image in a data grid

[MMIMadness]

hi all,

i have a data grid with one of the columns getting it feed from a TRUE/FALSE data field.

what i want to do is display a set image when the value is true and no image when it's false.

i have made the column a template field and added the image to the field, with the view of turning it on and off in code.

Item template

<ItemTemplate>
   <asp:Image ID="Image1" runat="server" Height="17px" ImageUrl="yesno.jpg" Width="19px" />
</ItemTemplate>

Event code

Public Function yesno(ByVal strdate As String) As String
   Dim image1 As Image
   image1 = CType(FindControl("image1"), Image)
   If strdate = True Then
      image1.Visible = True
   Else
      image1.Visible = False
   End If          
End Function

but as yet just can't crack it. Any ideas would be great.

 

[tperri]

when you step through your code is image1 null or it FindControl working?

in what event does Function yesno reside?

 

[MMIMadness]

opps, a little to much editing on my behalf.

<ItemTemplate>
   <asp:Label ID="Label1" runat="server" Text='<%#yesno(Server.HtmlEncode(eval("wireless").ToString()))%>'></asp:Label>
   <asp:Image ID="Image1" runat="server" Height="17px" ImageUrl="wireless.jpg" Width="19px" />
   </ItemTemplate>

and as far as i can make out findcontrol is working.

have only just started with .net much more used to classic :>

thanks for the swift reply.

 

[MMIMadness]

ignore the second part, just tried getting a value of image1 and it came back with

Object reference not set to an instance of an object.

so image1 is returning as NULL

 

[dvannoy]

the reason your getting that error is because your trying to refer to an object inside the grid without using the itemdatabound event of the grid. if you wish to write your own sub and call it, you will have to do something like this..

Dim dgItem As DataGridItem
Dim ck As CheckBox
Dim Img As Image

For Each dgItem In YourGrdi.Items
ck = dgItem.FindControl("ControlName")
Img = dgItem.FindControl("YourImageName")
If ck.Checked Then
Img.Visable = True
End If
Next

something like this...this is an example of looping through the grid to check if the check box is checked, if it is then the image is visable.