Why is this error happening? help appreciated.

Question

User186656733 posted

I have a page with a GridView with is bound by SqlDataSource.

The page also has 2 Textboxes that can be used to filter the data.

When user enters data into the filter, I change the SqlDataSource.SelectCommand, issue a SqlDataSource.Select() and rebind the GridView (MyGridView.DataBind() ).

All this works as long as the SqlDataSource.Select() returns at least 1 record.  If the SqlDataSource.Select() returns 0 records and user tries the filter again (with same or different filter data), this error occurs:

Invalid postback or callback argument.

Event validation is enabled using <pages enableEventValidation="true"/> in configuration or <%@ Page EnableEventValidation="true" %> in a page.

For security purposes, this feature verifies that arguments to postback or callback events originate from the server control that originally rendered them.  If the data is valid and expected, use the ClientScriptManager.RegisterForEventValidation method in order to register the postback or callback data for validation.

Why is this happening?

I have done a similar filter a thousand times before and have never seen this error.

Help is most appreciated..

Answer 1

User1992938117 posted

First of all if you have any code on Page Load the do as below:

if (!Page.IsPostBack)
{ 
    //do something
}

Also can avoid the error by adding below line on page directive.

EnableEventValidation="false" 

http://forums.asp.net/t/1275719.aspx

Answer 2

User186656733 posted

Thank you for these suggestions.

Your first suggestion seemed very reasonable, but, unfortunately the problem persists.

From everything I have read and seen, EnableEventValidation="false" should not be used.

Help most appreciated.

Answer 3

User697462465 posted

Hi Saavik,

    Invalid Postback or Callback argument in GridView Problem may be: You are binding data in Page_Load event with either Object Data Source or Manual Binding with function call. This will make your GridView bind data on every event fire of any control.

When you are firing any GridView command with OnRowCommand, before RowCommand fire your GridView will rebind and all control within it will be assigned to new id. So RowCommand could not get the item which have fired the event.

Solution for Invalid Postback or Callback argument in GridView: You can bind your data within this if condition

if (!IsPostBack)
{
    //Bind your GridView here...
}

Hope it helps.

Best Regards,
Terry Guo

Answer 4

User186656733 posted

Terry,

 

Thank you for this suggestion.  I tried it and, unfortunately, the problem persists.

I used !IsPostBack in Page_Load.  Obviously it cannot be used everywhere or the user will never be able to change the filter.

 

Ideas most appreciated.

Answer 5

User724169276 posted

could you post your code here ...