Displaying Sharepoint Custom List items in SPGridView

1. using System;  
2. using System.Runtime.InteropServices;  
3. using System.Web.UI;  
4. using System.Web.UI.WebControls;  
5. using System.Web.UI.WebControls.WebParts;  
6. using System.Xml.Serialization;  
7.   
8. using Microsoft.SharePoint;  
9. using Microsoft.SharePoint.WebControls;  
10. using Microsoft.SharePoint.WebPartPages;  
11.   
12. namespace FiveNumber  
13. {  
14.     [Guid("e6a48f2e-8f31-4738-8ed6-6629f985956d")]  
15.     public class DisplayListInSpGridView : System.Web.UI.WebControls.WebParts.WebPart  
16.     {  
17.         SPGridView myGridView;  
18.         SPDataSource myDataSource = new SPDataSource();  
19.   
20.         protected override void CreateChildControls()  
21.         {  
22.             myGridView = new SPGridView();  
23.             myGridView.Enabled = true;  
24.             myGridView.AutoGenerateColumns = false;  
25.             myGridView.ID = "gv_MyGridView";  
26.   
27.             myGridView.AllowGrouping = true;  
28.             myGridView.AllowGroupCollapse = true;  
29.             myGridView.GroupField = "Country";  
30.             myGridView.GroupDescriptionField = "Country";  
31.             //myGridView.GroupFieldDisplayName = "Country Name";  
32.   
33.             BoundField colTitle = new BoundField();  
34.             colTitle.DataField = "Country";  
35.             colTitle.HeaderText = "Country";  
36.             this.myGridView.Columns.Add(colTitle);  
37.   
38.             BoundField colMission = new BoundField();  
39.             colMission.DataField = "State";  
40.             colMission.HeaderText = "State";  
41.             this.myGridView.Columns.Add(colMission);  
42.   
43.             this.Controls.Add(myGridView);  
44.         }  
45.   
46.         protected override void Render(HtmlTextWriter writer)  
47.         {  
48.             SPSite site = SPContext.Current.Site;  
49.             SPWeb web = SPContext.Current.Web;  
50.             SPList list = web.Lists["Countries"];  
51.             myDataSource.List = list;  
52.             myGridView.DataSource = myDataSource;  
53.             myGridView.DataBind();              
54.   
55.             myGridView.RenderControl(writer);  
56.         }  
57.     }  
58. }