在使用DataGrid时,如果页面很长,可能需要用户自己来拉动滚动条,下面的例子实现了自动滚动的功能。其基本原理就是利用了LinkButton的锚点的功能,如果使用PushButton,那还必须自己添加锚点。另外必须弄明白的是Page的PostBack时的客户端脚本:<script language="javascript"> <!-- function __doPostBack(eventTarget, eventArgument) { var theform = document.Form1; theform.__EVENTTARGET.value = eventTarget; theform.__EVENTARGUMENT.value = eventArgument; theform.submit(); } // --> </script>这段脚本中__doPostBack函数有两个参数:第一个eventTarget是触发PostBack的控件的UniqueID;第二参数eventArgument是一个对象,包含PostBack的额外信息。因此我们使用UniqueID来作为锚点的值。源代码如下: DataGridAutoScroll.aspx<%@ Page Language="vb" AutoEventWireup="false" Codebehind="DataGridAutoScroll.aspx.vb" Inherits="aspxWeb.DataGridAutoScroll"%> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML> <HEAD> <title runat="server" id="mengxianhui"></title> <meta name="GENERATOR" content="Microsoft Visual Studio.NET 7.0"> <meta name="CODE_LANGUAGE" content="Visual Basic 7.0"> <meta name="vs_defaultClientScript" content="JavaScript"> <meta name="vs_targetSchema" content="http://schemas.microsoft.com/intellisense/ie5"> </HEAD> <body> <form id="Form1" method="post" runat="server"> <asp:DataGrid id="DataGrid1" runat="server" BorderColor="#CC9966" BorderStyle="None" BorderWidth="1px" BackColor="White" CellPadding="4"> <SelectedItemStyle Font-Bold="True" ForeColor="#663399" BackColor="#FFCC66"></SelectedItemStyle> <ItemStyle ForeColor="#330099" BackColor="White"></ItemStyle> <HeaderStyle Font-Bold="True" ForeColor="#FFFFCC" BackColor="#990000"></HeaderStyle> <FooterStyle ForeColor="#330099" BackColor="#FFFFCC"></FooterStyle> <Columns> <asp:EditCommandColumn ButtonType="LinkButton" UpdateText="Update" CancelText="Cancel" EditText="Edit"></asp:EditCommandColumn> </Columns> <PagerStyle HorizontalAlign="Center" ForeColor="#330099" BackColor="#FFFFCC"></PagerStyle> </asp:DataGrid> </form> </body> </HTML>代码:DataGridAutoScroll.aspx.vbImports System Imports System.Web Imports System.Web.UI.WebControls Imports System.Collections Imports System.Data Imports System.Data.SqlClientPublic Class DataGridAutoScroll Inherits System.Web.UI.Page Protected WithEvents DataGrid1 As System.Web.UI.WebControls.DataGrid Protected mengxianhui As New HtmlGenericControl()#Region " Web Form Designer Generated Code " <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent() End Sub Private Sub Page_Init(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Init InitializeComponent() End Sub#End Region Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load mengxianhui.InnerText = "【孟宪会之精彩世界】之.NET开发者园地" If Not Page.IsPostBack Then DataGrid1.DataSource = CreateDataSource() DataGrid1.DataBind() Else Dim startUpScript As String startUpScript = "<script language=Javascript>location.href='#" _ & Request.Form("__EVENTTARGET") & "';</script>" Me.RegisterStartupScript(Me.UniqueID & "StartUp", startUpScript) End If End Sub Function CreateDataSource() As ICollection Dim dt As DataTable Dim dr As DataRow Dim i As Integer '创建 DataTable dt = New DataTable() dt.Columns.Add(New DataColumn("字符型值", GetType(String))) dt.Columns.Add(New DataColumn("布尔型值", GetType(Boolean))) dt.Columns.Add(New DataColumn("货币型值", GetType(Double))) '示例数据 For i = 1 To 150 dr = dt.NewRow() dr(0) = "Item " + i.ToString() If (i Mod 2 <> 0) Then dr(1) = True Else dr(1) = False End If dr(2) = 1.23 * (i + 1) '向datatable添加 row dt.Rows.Add(dr) Next '返回DataTable的DataView CreateDataSource = New DataView(dt) End Function Private Sub DataGrid1_ItemDataBound(ByVal sender As Object, _ ByVal e As System.Web.UI.WebControls.DataGridItemEventArgs) Handles DataGrid1.ItemDataBound Select Case e.Item.ItemType Case ListItemType.Item, ListItemType.AlternatingItem Dim editButton As LinkButton = New LinkButton() editButton = CType(e.Item.Cells(0).Controls(0), LinkButton) editButton.Attributes.Add("name", "#" & editButton.UniqueID) Case ListItemType.EditItem Dim UpdateButton As LinkButton = New LinkButton() UpdateButton = CType(e.Item.Cells(0).Controls(0), LinkButton) UpdateButton.Attributes.Add("name", "#" & UpdateButton.UniqueID) End Select End Sub Private Sub DataGrid1_EditCommand(ByVal source As Object, _ ByVal e As System.Web.UI.WebControls.DataGridCommandEventArgs) Handles DataGrid1.EditCommand DataGrid1.EditItemIndex = e.Item.ItemIndex DataGrid1.DataSource = CreateDataSource() DataGrid1.DataBind() End Sub Private Sub DataGrid1_CancelCommand(ByVal source As Object, _ ByVal e As System.Web.UI.WebControls.DataGridCommandEventArgs) Handles DataGrid1.CancelCommand DataGrid1.EditItemIndex = -1 DataGrid1.DataSource = CreateDataSource() DataGrid1.DataBind() End Sub Private Sub DataGrid1_UpdateCommand(ByVal source As Object, _ ByVal e As System.Web.UI.WebControls.DataGridCommandEventArgs) Handles DataGrid1.UpdateCommand DataGrid1.EditItemIndex = -1 DataGrid1.DataSource = CreateDataSource() DataGrid1.DataBind() End Sub End Class
<!--
function __doPostBack(eventTarget, eventArgument) {
var theform = document.Form1;
theform.__EVENTTARGET.value = eventTarget;
theform.__EVENTARGUMENT.value = eventArgument;
theform.submit();
}
// -->
</script>这段脚本中__doPostBack函数有两个参数:第一个eventTarget是触发PostBack的控件的UniqueID;第二参数eventArgument是一个对象,包含PostBack的额外信息。因此我们使用UniqueID来作为锚点的值。源代码如下:
DataGridAutoScroll.aspx<%@ Page Language="vb" AutoEventWireup="false" Codebehind="DataGridAutoScroll.aspx.vb"
Inherits="aspxWeb.DataGridAutoScroll"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML>
<HEAD>
<title runat="server" id="mengxianhui"></title>
<meta name="GENERATOR" content="Microsoft Visual Studio.NET 7.0">
<meta name="CODE_LANGUAGE" content="Visual Basic 7.0">
<meta name="vs_defaultClientScript" content="JavaScript">
<meta name="vs_targetSchema" content="http://schemas.microsoft.com/intellisense/ie5">
</HEAD>
<body>
<form id="Form1" method="post" runat="server">
<asp:DataGrid id="DataGrid1" runat="server" BorderColor="#CC9966" BorderStyle="None"
BorderWidth="1px" BackColor="White" CellPadding="4">
<SelectedItemStyle Font-Bold="True" ForeColor="#663399" BackColor="#FFCC66"></SelectedItemStyle>
<ItemStyle ForeColor="#330099" BackColor="White"></ItemStyle>
<HeaderStyle Font-Bold="True" ForeColor="#FFFFCC" BackColor="#990000"></HeaderStyle>
<FooterStyle ForeColor="#330099" BackColor="#FFFFCC"></FooterStyle>
<Columns>
<asp:EditCommandColumn ButtonType="LinkButton" UpdateText="Update"
CancelText="Cancel" EditText="Edit"></asp:EditCommandColumn>
</Columns>
<PagerStyle HorizontalAlign="Center" ForeColor="#330099" BackColor="#FFFFCC"></PagerStyle>
</asp:DataGrid>
</form>
</body>
</HTML>代码:DataGridAutoScroll.aspx.vbImports System
Imports System.Web
Imports System.Web.UI.WebControls
Imports System.Collections
Imports System.Data
Imports System.Data.SqlClientPublic Class DataGridAutoScroll
Inherits System.Web.UI.Page
Protected WithEvents DataGrid1 As System.Web.UI.WebControls.DataGrid
Protected mengxianhui As New HtmlGenericControl()#Region " Web Form Designer Generated Code "
<System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
End Sub Private Sub Page_Init(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Init
InitializeComponent()
End Sub#End Region Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
mengxianhui.InnerText = "【孟宪会之精彩世界】之.NET开发者园地"
If Not Page.IsPostBack Then
DataGrid1.DataSource = CreateDataSource()
DataGrid1.DataBind()
Else
Dim startUpScript As String
startUpScript = "<script language=Javascript>location.href='#" _
& Request.Form("__EVENTTARGET") & "';</script>"
Me.RegisterStartupScript(Me.UniqueID & "StartUp", startUpScript)
End If End Sub Function CreateDataSource() As ICollection Dim dt As DataTable
Dim dr As DataRow
Dim i As Integer '创建 DataTable
dt = New DataTable()
dt.Columns.Add(New DataColumn("字符型值", GetType(String)))
dt.Columns.Add(New DataColumn("布尔型值", GetType(Boolean)))
dt.Columns.Add(New DataColumn("货币型值", GetType(Double))) '示例数据
For i = 1 To 150
dr = dt.NewRow()
dr(0) = "Item " + i.ToString()
If (i Mod 2 <> 0) Then
dr(1) = True
Else
dr(1) = False
End If
dr(2) = 1.23 * (i + 1)
'向datatable添加 row
dt.Rows.Add(dr)
Next '返回DataTable的DataView
CreateDataSource = New DataView(dt) End Function Private Sub DataGrid1_ItemDataBound(ByVal sender As Object, _
ByVal e As System.Web.UI.WebControls.DataGridItemEventArgs) Handles DataGrid1.ItemDataBound
Select Case e.Item.ItemType
Case ListItemType.Item, ListItemType.AlternatingItem
Dim editButton As LinkButton = New LinkButton()
editButton = CType(e.Item.Cells(0).Controls(0), LinkButton)
editButton.Attributes.Add("name", "#" & editButton.UniqueID) Case ListItemType.EditItem
Dim UpdateButton As LinkButton = New LinkButton()
UpdateButton = CType(e.Item.Cells(0).Controls(0), LinkButton)
UpdateButton.Attributes.Add("name", "#" & UpdateButton.UniqueID)
End Select
End Sub Private Sub DataGrid1_EditCommand(ByVal source As Object, _
ByVal e As System.Web.UI.WebControls.DataGridCommandEventArgs) Handles DataGrid1.EditCommand
DataGrid1.EditItemIndex = e.Item.ItemIndex
DataGrid1.DataSource = CreateDataSource()
DataGrid1.DataBind()
End Sub Private Sub DataGrid1_CancelCommand(ByVal source As Object, _
ByVal e As System.Web.UI.WebControls.DataGridCommandEventArgs) Handles DataGrid1.CancelCommand
DataGrid1.EditItemIndex = -1
DataGrid1.DataSource = CreateDataSource()
DataGrid1.DataBind()
End Sub Private Sub DataGrid1_UpdateCommand(ByVal source As Object, _
ByVal e As System.Web.UI.WebControls.DataGridCommandEventArgs) Handles DataGrid1.UpdateCommand
DataGrid1.EditItemIndex = -1
DataGrid1.DataSource = CreateDataSource()
DataGrid1.DataBind()
End Sub
End Class