Gridview CommandField validation works, but not firing Delete method

Question

I have a gridview that I'm trying to validate from code behind. In this case, to confirm a record deletion. My deletion method works fine until I add the validation which, when I implement it, it doesn't fire the deletion.

To be clear, the deletion methods work correctly until I add the RowDataBound validation.

<asp:CommandField 
        ButtonType="Image"
        ShowEditButton="true" 
        ShowDeleteButton="true" 
        ShowCancelButton="true"
        EditImageUrl="~/Images/edit-icon.gif" 
        UpdateImageUrl="~/Images/save-icon.png"
        CancelImageUrl="~/Images/cancel-icon.png" 
        DeleteImageUrl="~/Images/delete-icon.png" 
        />

Here are the relevant methods.

Protected Sub usersGrid_RowDataBound(ByVal sender As Object, ByVal e As GridViewRowEventArgs)
For Each control As Control In e.Row.Cells(0).Controls
        Dim DeleteButton As ImageButton = TryCast(control, ImageButton)
        If DeleteButton IsNot Nothing AndAlso DeleteButton.CommandName = "Delete" Then
            DeleteButton.OnClientClick = "return(confirm('Are you sure you want to delete this user?\nThis cannot be undone!'))"
        End If
    Next
End Sub

Protected Sub usersGrid_RowDeleting(ByVal sender As Object, ByVal e As GridViewDeleteEventArgs)
    Dim userID As Integer = DirectCast(usersGrid.DataKeys(e.RowIndex).Value, Integer)

    usersGrid_Delete(userID)
    BindData()
End Sub

Protected Sub usersGrid_Delete(ByVal userID As Integer)
    Dim con As New SqlConnection(connectionString)
    Dim cmd As New SqlCommand("MAINT_DIST_DELETE_USER", con)
    cmd.CommandType = CommandType.StoredProcedure
    cmd.Parameters.AddWithValue("@userID", userID)

    Try
        con.Open()
        cmd.ExecuteNonQuery()
    Catch Ex As Exception
        Throw Ex
    Finally
        con.Close()
    End Try
End Sub

It's not very clear what the problem is. When you say "it doesn't fire deletion", does an error occur? Do the `RowDeleting` or `RowDataBound` events not fire? — Josh Darnell, Nov 21 '11 at 15:38
No, no errors are occurring. If I leave out the validation I'm using in RowDataBound, the deletion occurs as expected. If I leave this method in, nothing happens. No error, but deletion doesn't happen. — John Kinane, Nov 21 '11 at 15:43

score 3 · Accepted Answer · answered Nov 21 '11 at 16:14

You may use following code (I hope you know C# enough to translate it to VB.NET):

void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
{
    if (e.Row.RowType == DataControlRowType.DataRow)
    {
        var deleteButton = e.Row.Cells[0].Controls.OfType<ImageButton>().FirstOrDefault(btn => btn.CommandName == "Delete");
        if (deleteButton != null)
        {
            deleteButton.OnClientClick =
                string.Format("javascript:if(confirm('Are you sure you want to delete this user? This cannot be undone!')){{ __doPostBack('{0}', 'Delete${1}');}} return false;", GridView1.UniqueID, e.Row.RowIndex);
        }
    }
}

The reason is that ImageButton control use onclick attribute to fire a postback whereas your code completely remove it's default value and postback doesn't occured at all.

Gridview CommandField validation works, but not firing Delete method

1 Answers1