Display mulitple data column fields in one BoundField of GridView in ASP.Net

HTML: you have to use TemplateField inside column and set the headertext property. Make sure that gridview AutoGenerateColumns property is set to false

<asp:GridView ID="gvColumnDemo" runat="server" AutoGenerateColumns="false">
        <Columns>
        <asp:TemplateField HeaderText="Empolyee Details">
        <ItemTemplate>
        <asp:Label ID="lblId" runat="server" Text='<%#Eval("Id") %>'></asp:Label>
        <asp:Label ID="lblName" runat="server" Text='<%#Eval("Name") %>'></asp:Label>
        <asp:Label ID="Label1" runat="server" Text='<%#Eval("Country") %>'></asp:Label>
        </ItemTemplate>
        </asp:TemplateField>
        </Columns>
        </asp:GridView>

CODE: Here i have binded gridview with dummy table

             DataTable dt = new DataTable();
            dt.Columns.AddRange(new DataColumn[3] { new DataColumn("Id", typeof(int)), 
                            new DataColumn("Name", typeof(string)), 
                            new DataColumn("Country",typeof(string)) });
            dt.Rows.Add(1, "John Hammond", "United States");
            dt.Rows.Add(2, "Mudassar Khan", "India");
            dt.Rows.Add(3, "Suzanne Mathews", "France");
            dt.Rows.Add(4, "Robert Schidner", "Russia");
	    gvColumnDemo.DataSource = dt;
            gvColumnDemo.DataBind();