gridview中的图像按钮回发无效

Question

当我点击gridview中的图像按钮删除行时，我遇到了这个gridview的问题。我有这个代码

       <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False">
                                    <Columns>
                                        <asp:BoundField DataField="Username" HeaderText="Login Name">
                                        <ItemStyle Width="150px" />
                                        </asp:BoundField>
                                        <asp:BoundField DataField="Question" HeaderText="Question">
                                        <ItemStyle Width="200px" />
                                        </asp:BoundField>
                                        <asp:BoundField DataField="Answer" HeaderText="Answer">
                                        <ItemStyle Width="150px" />
                                        </asp:BoundField>
                                        <asp:TemplateField ShowHeader="False">
                                            <ItemTemplate>
                                                <asp:ImageButton ID="ImageButton1" runat="server" CausesValidation="False" AutoPostback = "True"  
                                                    CommandName="Select" ImageUrl="~/images/trash.png" Text="Select" OnClientClick="return confirm('Do you want to delete?');" />
                                            </ItemTemplate>
                                        </asp:TemplateField>

当我点击垃圾图片删除任何行时，它会给我错误。无效的回发或回调参数。 这是我的vb.net代码

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Private Sub updatedata(ByVal sql As String)
        connectdb()
        cmd = New SqlCommand
        cmd.Connection = conn
        cmd.CommandType = CommandType.Text
        cmd.CommandText = sql
        cmd.ExecuteNonQuery()
        conn.Close()

    End Sub
    Protected Sub GridView1_SelectedIndexChanged(sender As Object, e As System.EventArgs) Handles GridView1.SelectedIndexChanged
        Dim sql4 As String = "delete from login WHERE  username='" & GridView1.SelectedRow.Cells(0).Text.Trim() & "' "
        updatedata(sql4)

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