How to disable a button in datagrid asp.net

Question

I just want to ask how can I disable the first button (the one with "Test1") in datagrid (see attached picture).

Below is my code in aspx page

Please help in creating the codes in its code behind.

<asp:datagrid id="RecordsGrid" runat="server" CellSpacing="0" CellPadding="0" BorderWidth="0" Width="100%" GridLines="None">
<SelectedItemStyle CssClass="selecteditem"></SelectedItemStyle> 
<AlternatingItemStyle CssClass="alternatingitem"></AlternatingItemStyle>
<ItemStyle Wrap="False" CssClass="item"></ItemStyle> 
<HeaderStyle CssClass="headerdatagrid"></HeaderStyle> 
<FooterStyle CssClass="footerline"></FooterStyle> 
<Columns> 
<asp:ButtonColumn Text="View/Update" CommandName="Button1">
</asp:ButtonColumn> 
</Columns> 
</asp:datagrid>