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Asp.Net实例:创建自滚动的DataGrid

点击次数:845  更新日期:2010-12-27
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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:


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<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。


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源代码如下:


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查看例子


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DataGridAutoScroll.aspx


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<%@ 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.vb


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Imports System
Imports System.Web
Imports System.Web.UI.WebControls
Imports System.Collections
Imports System.Data
Imports System.Data.SqlClient


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Public Class DataGridAutoScroll
Inherits System.Web.UI.Page
Protected WithEvents DataGrid1 As System.Web.UI.WebControls.DataGrid
Protected mengxianhui As New HtmlGenericControl()


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#Region ” Web Form Designer Generated Code “
<System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
End Sub


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Private Sub Page_Init(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Init
InitializeComponent()
End Sub


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#End Region


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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


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End Sub


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Function CreateDataSource() As ICollection


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Dim dt As DataTable
Dim dr As DataRow
Dim i As Integer


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‘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)))


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‘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


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‘返回DataTable的DataView
CreateDataSource = New DataView(dt)


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End Function


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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)


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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


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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


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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


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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


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出自:【孟宪会之精彩世界】

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