Get RowCount or RecordCount

I could'nt get the question properly.....
But if you want the rrow count of the dataset then use

Datasetname.tables[0].rows.count

DatasetName.(which ever table you want from dataset).rows.count    basic way of getting the row count froma dataset.

the code is in the c# language.

I am not sure I entirely understand your question.  
If you have a dataset that contains 23 records and your gridview is set to display 10 records at a time, do you want to return 10 as the 1st gridview page count, 10 as the 2nd gridview page count and 3 for the 3rd gridview page count?
Or do you want to return 23 the total number of records in the dataset?

I need to return the total number of records returned by the objectDataSource.

Use the "Selected" declaration for your ObjectDataSource like so:

Private Sub ObjectDataSource1_Selected(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.ObjectDataSourceStatusEventArgs) Handles ObjectDataSource1.Selected
    'Now, utilize the following code within that subroutine:
    Dim numRows As Integer = (e.ReturnValue).Tables(0).Rows.Count

End Sub

I get:

Public member 'Tables' on type 'myStoredprocedureDataTable' not found.

There will be a point in your code where you fill a dataset.  Let us assume this dataset is named "ds".  The fill may look something like this:

// Populate DataSet
DataSet ds = new DataSet();
da.Fill(ds, "FormDef");
After the Fill Command has been executed, you can use this statement to provide the rowcount.
ds.Tables[0].Rows.Count
Hope this helps.  If it doesn't, can you post the code you have created up to this point?

>> Public member 'Tables' on type 'myStoredprocedureDataTable' not found.

Can you show how you select your data with the ObjectDataSource

In this particular case, I've not written code to connect the ODS. I've simply dragged it from the toolbar onto my application, set it up so that the appropriate values are sent to the stored procedure then bound it to a gridview.