<asp:GridView ID="base_gvMain" runat="server"  Width="100%" OnRowCommand="base_gvMain_RowCommand">


<asp:TemplateField HeaderText="查看PLC现象">
                   <ItemTemplate>
                     <asp:Button ID="btnPLC" Text="查看PLC现象" CssClass="btn_long" CommandName="PLC" CommandArgument="<%# ((GridViewRow)Container).RowIndex %>" runat="server" />
                     <asp:TextBox ID="txtValue" runat="server"/>
                   </ItemTemplate>
                </asp:TemplateField>

------解决方案--------------------
 <asp:Button ID="CheckButton" runat="server" Text="查看" CommandArgument= <%# Container.DisplayIndex%>
            OnCommand="CheckButton_Click"/>

protected void CheckButton_Click(object sender, CommandEventArgs e)
   {
       string studentcode = e.CommandArgument.ToString();
   }

------解决方案--------------------
code=C#]
protected void GridView1_RowCommand(object sender, GridViewCommandEventArgs e)
   {
       if (e.CommandName == "MyCommand")
       {
           Button button = (Button)e.CommandSource;
           GridViewRow row = (GridViewRow)button.Parent.Parent;
           string a = row.Cells[1].Text.ToString();//获得第一个单元格的值  
           string b = this.GridView1.DataKeys[row.DataItemIndex].Values[0];//获得DataKeys的值  
       }
   }
[/code]