Help with checkbox update function in GridView for GridView.Rows

I need help with the syntax below to finish my function which will be the update function for the onclick event for the submit button that will update all checkboxes in my GridView.  So far, I'm close but not getting quite the right syntax:

    Public Sub UpdateCustomer_DashboardGraphs(ByVal sender As Object, ByVal e As System.EventArgs)
        For Each gvr As GridViewRow In gv_dashboard.Rows
            If gvr.RowType = DataControlRowType.DataRow Then
                Dim intCustomerID As Integer = CType(gvr.FindControl("lblCustomerID"), Label).Text.Trim()
                Dim intCurrentMonthCollections As CheckBox = gvr.FindControl("chbx_CurrentMonthCollections")
                Dim intRevenueByMonth As CheckBox = gvr.FindControl("chbx_RevenueByMonth")
                Dim intPDCsCCsMonthly As CheckBox = gvr.FindControl("chbx_PDCsCCsMonthly")
                Dim intRevenueByClient As CheckBox = gvr.FindControl("chbx_RevenueByClient")

                ds_dashboard.UpdateParameters("CustomerID").DefaultValue = intCustomerID
                ds_dashboard.UpdateParameters("CurrentMonthCollections").DefaultValue = intCurrentMonthCollections
                ds_dashboard.UpdateParameters("RevenueByMonth").DefaultValue = intRevenueByMonth
                ds_dashboard.UpdateParameters("PDCsCCsMonthly").DefaultValue = intPDCsCCsMonthly
                ds_dashboard.UpdateParameters("RevenueByClient").DefaultValue = intRevenueByClient
                ds_dashboard.Update()
            End If
        Next
    End Sub

My SQLDtaSource:

        <asp:SqlDataSource
            ID="ds_dashboard"
            runat="server"
            ConnectionString="<%$ ConnectionStrings:DashboardConn %>"
            SelectCommand="Get_Customer_DashboardGraphs"
            SelectCommandType="StoredProcedure"
            UpdateCommand="Update_Customer_DashboardGraphs"
            UpdateCommandType="StoredProcedure"
            >
            <UpdateParameters>
                    <asp:Parameter Name="CustomerID" Type="Int32" />
                    <asp:Parameter Name="CurrentMonthCollections" Type="Boolean" />
                    <asp:Parameter Name="RevenueByMonth" Type="Boolean" />
                    <asp:Parameter Name="PDCsCCsMonthly" Type="Boolean" />
                    <asp:Parameter Name="RevenueByClient" Type="Boolean" />                                      
            </UpdateParameters>  
 
        </asp:SqlDataSource>


Errors I'm getting with my function:

Value of type 'System.Web.UI.WebControls.CheckBox' cannot be converted to 'String'
...