利用Session纪录datagrid模板列中CheckBox的状态

在DataGrid 的模板列中加入CheckBox ,如果对DataGrid设置分页，前一页已经选中的CheckBox在回到原页时，CheckBox的状态会变为初始状态。
如果想保存checkbox的状态，则可以用Session保存，我是这样实现的：
1、首先，建立DataGrid.
<asp:datagrid id="DataGrid1" style="Z-INDEX: 101; LEFT: 12px; POSITION: absolute; TOP: 88px" runat="server" AllowPaging="True" Width="416px" Height="248px">
<AlternatingItemStyle BackColor="#EEEEEE"></AlternatingItemStyle>
<ItemStyle Font-Size="12px" Font-Names="宋体"></ItemStyle>
<HeaderStyle Font-Size="12px" Font-Names="宋体" BackColor="#00CCFF"></HeaderStyle>
<FooterStyle HorizontalAlign="Center"></FooterStyle>
<Columns>
<asp:TemplateColumn>
<ItemTemplate>
<asp:checkbox id="CheckBox1" runat="server"></asp:checkbox>
</ItemTemplate>
</asp:TemplateColumn>
</Columns>
</asp:datagrid>

2、在Global.asax文件中，Session_Start事件中建立Session
Sub Session_Start(ByVal sender As Object, ByVal e As EventArgs)
' 在会话启动时激发
Dim checks As Boolean() = New Boolean(10000) {}
Dim i As Integer
For i = 0 To 10000
checks(i) = False
Next
Session.Add("CheckBoxchecks", checks)
End Sub
3.在DataGrid的PageIndexChanged事件中：
Private Sub DataGrid1_PageIndexChanged(ByVal source As Object, ByVal e As System.Web.UI.WebControls.DataGridPageChangedEventArgs) Handles DataGrid1.PageIndexChanged
Dim count As Integer
Dim cnn As OleDb.OleDbConnection = New OleDb.OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=c:/UserLog.mdb")
Dim da As New OleDb.OleDbDataAdapter("select * from mm", cnn)

da.Fill(dst)

count = dst.Tables(0).Rows.Count 'DataGrid中的记录总数；
Dim check As Boolean()
check = Me.Session("checkboxchecks") 'check()是记录checkbox状态的数组，用session保存。
Dim j As Integer
For j = 0 To DataGrid1.PageSize - 1
Dim Che As CheckBox = DataGrid1.Items(j).Cells(0).FindControl("CheckBox1")
If Not Che Is Nothing Then
If Che.Checked = True Then
check(DataGrid1.CurrentPageIndex * DataGrid1.PageSize + j) = True
Else
check(DataGrid1.CurrentPageIndex * DataGrid1.PageSize + j) = False
End If
End If
Next
DataGrid1.CurrentPageIndex = e.NewPageIndex
Dim ds As New DataSet()
da.Fill(ds, "a")
DataGrid1.DataSource = ds
DataGrid1.DataBind()
Dim i As Integer
For i = 0 To DataGrid1.PageSize - 1
Dim Cx2 As CheckBox = DataGrid1.Items(i).Cells(0).FindControl("CheckBox1")
If check(DataGrid1.CurrentPageIndex * DataGrid1.PageSize + i) = True Then
Cx2.Checked = True
Else
Cx2.Checked = False
End If
Next

End Sub