[ASP.NET]在DataGrid列页眉中添加全选CheckBox

步骤：

1.在DataGrid中添加模板列，设计视图中编辑该模板列,从工具箱中拖入一个CheckBox到到HeaderTemplate中，将CheckBox命名为chkAll，自动回发autopostback属性设为True;拖入一个CheckBox到到ItemTemplate。

2.打开HTML视图找到该CheckBox,并添加选择事件oncheckedchanged

<headertemplate>
                                <asp:checkbox id="chkAll" runat="server" oncheckedchanged="SelectAll" autopostback="True"></asp:checkbox>
                            </headertemplate>

3.按F7进入源代码视图,添加事件处理方法,

Imports System.Web.UI.WebControls

Public Sub SelectAll(ByVal sender As System.Object, ByVal e As System.EventArgs)
        If dtgReports.Items.Count = 0 Then Exit Sub
        Dim item As DataGridItem
        For Each item In dtgReports.Items
            CType(item.FindControl("CheckBox1"), CheckBox).Checked = CType(sender, CheckBox).Checked
        Next
    End Sub