Storing the Key from GridView RSS

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  crippsy

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  Storing the Key from GridView

  Jul 02, 2006 03:21 PM|LINK

  I am looking to store the value from the selected record in a GridView so that I can Navigate to a new page with this as a session variable.

  I have tried many variations of the code (held in the master page) but get a variation of issue. The simplified version of the code below returns and issue that GridView1 is not declared. As you can see from the Sub my gridview is called Grid view1. If I uncomment the Dim statement for Gridview1 and run the screen i get "Exception Details: System.NullReferenceException: Object reference not set to an instance of an object"

   

  Protected Sub GridView1_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs)

   ' Dim Gridview1 As GridView

  Dim NewText As String

  NewText = GridView1.Cells(0)

  Session("Table_ID") = NewText

  Response.Redirect("../Newpage.aspx")

  End Sub

   

  I have also tried variations on what to put in place of the system.EventsArgs and replacing

  "NewText = GridView1.Cells(0)"

  with

  "NewText = e.item.Cells(0)"

  as I have seen e.item in other examples but the item does not seem to be a member of System.EventArgs or the other variations I use (i.e GridViewCommandEventArgs)

  However DataGridItemEventArgs does allow e.items.Cells(0) but returns the error that it " does not have the same signature as delegate 'Delegate Sub EventHandler(sender As Object, e As System.EventArgs) "

  Any advice would be most greatfully recieved

   

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  e_screw

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  Re: Storing the Key from GridView

  Jul 02, 2006 05:05 PM|LINK

  Hi,
  Set the DataKeyNames of the GridView to the primaryKey of your data, so you can access the value of the selected DataKey in your code this way..
  
  GridView1.SelectedDataKey.Value
  
  Thanks
  
  Mark post(s) as "Answer" that helped you
  
  Electronic Screw
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  crippsy

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  60 Posts

  Re: Storing the Key from GridView

  Jul 02, 2006 06:54 PM|LINK

  Thanks for the advice and such a quick responce.

  First of all I set I set

  NewText = GridView1.SelectedDataKey.Values

  and I get an error that GridView1 is not Declared, so in the same sub I set

  Dim Gridview1 As GridView

  However it now warns me that

  Variable 'GridView1' is used befor it has been assigned a value. A null reference exception could result at runtime.

  Which it does.

  Could part of the issue be that it is set in the Master page? also another quirk but probably not affect this issue is that this GridView has 2 dataKeys set as it is using two joined tables.

  Any further views,?

  Thanks in advance.

   

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  e_screw

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  Re: Storing the Key from GridView

  Jul 02, 2006 07:07 PM|LINK

  Hi,
  When you were using MasterPages, you need to find the GridView control and its not that you declare a variable as GridView.
  Have a look at this article, MasterPages and FindControl()
  
  You can have multiple datakeys defined for a GridView.
  
  Thanks
  
  Mark post(s) as "Answer" that helped you
  
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  crippsy

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  60 Posts

  Re: Storing the Key from GridView

  Jul 03, 2006 10:22 PM|LINK

  Got there in the end thanks to your help. I was using the Findcontrol command, but was doing this in the Master document and not the child document. I have now moved the source to the child document and this now works well.

  Many thanks again

  Simon 

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  ReyN

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  Re: Storing the Key from GridView

  Jul 04, 2006 06:41 AM|LINK

  with DataKeyNames, you can simply use

  GridView.SelectedValue [;)]

  Reynald V. Nuñez
  aspxtreme