How To Understand CheckBox Related Row in GridView!!!?

See more:

ASP.NET

hi all
i dont English Very Well
Excusme me!
i have one GridView inside it CheckBox

<Columns>
     <asp:TemplateField>
          <ItemTemplate>

<asp:LinkButton runat="server" CommandArgument='<%# Eval("Id_Question") %>' OnCommand="LinkButton_Click"> </asp:LinkButton>

 <asp:CheckBox ClientIDMode="Static" ID="CheckBoxItem" runat="server" Class="CheckBoxNotification"  />


 </ItemTemplate>
           </asp:TemplateField>
                </Columns>

and ServersideCode is :

for (int i = 0; i < GridView1.Rows.Count; i++)
     {
         CheckBox checkbox =      (CheckBox)GridView1.Rows[i].FindControl("CheckBoxItem");
         if (checkbox.Checked == true)
         {

           //I need Something like CommandArgument that indicate what CheckBox Need to Manipulate!!!

         }
     }

please Help Me Its Very Necessary!Thanks so much