如何在DataGrid绑定之前为DataSet添加新列

2022-07-15 80酷酷网 80kuku.com

　　datagrid

在实际的应用中经常会遇到根据其它列计算某一新列的结果，实现这样的功能有两种办法：一个直接使用SQL语句；另外就是在绑定时进行动态添加。第一种方法以前已经介绍过。下面就是第二种方法的具体实现：

AddDataSetColumn.aspx

<% Page Language="vb" AutoEventWireup="false" Codebehind="AddDataSetColumn.<a content="JavaScript">

<meta name="vs_targetSchema" content="http://schemas.microsoft.com/intellisense/ie5">

</HEAD>

<body MS_POSITIONING="GridLayout">

<form id="Form1" method="post" runat="server">

<<a href="http://www.chinaitpower.com/Dev/Web/Asp/index.html" target="_blank">asp</a>:DataGrid id="DataGrid1" runat="server" AutoGenerateColumns="False"

ShowFooter="True" Width="100%">

<HeaderStyle Font-Names="宋体" Font-Bold="True" HorizontalAlign="Center"

ForeColor="Navy" BackColor="LightSalmon"></HeaderStyle>

<FooterStyle BackColor="#FFCCFF"></FooterStyle>

<Columns>

<<a href="http://www.chinaitpower.com/Dev/Web/Asp/index.html" target="_blank">asp</a>:TemplateColumn HeaderText="订单号">

<ItemTemplate>

<<a href="http://www.chinaitpower.com/Dev/Web/Asp/index.html" target="_blank">asp</a>:Label ID="OrderID" Runat="server"></<a href="http://www.chinaitpower.com/Dev/Web/Asp/index.html" target="_blank">asp</a>:Label>

</ItemTemplate>

</<a href="http://www.chinaitpower.com/Dev/Web/Asp/index.html" target="_blank">asp</a>:TemplateColumn>

<<a href="http://www.chinaitpower.com/Dev/Web/Asp/index.html" target="_blank">asp</a>:TemplateColumn HeaderText="产品号">

<ItemTemplate>

<<a href="http://www.chinaitpower.com/Dev/Web/Asp/index.html" target="_blank">asp</a>:Label ID="ProductID" Runat="server"></<a href="http://www.chinaitpower.com/Dev/Web/Asp/index.html" target="_blank">asp</a>:Label>

</ItemTemplate>

</<a href="http://www.chinaitpower.com/Dev/Web/Asp/index.html" target="_blank">asp</a>:TemplateColumn>

<<a href="http://www.chinaitpower.com/Dev/Web/Asp/index.html" target="_blank">asp</a>:TemplateColumn HeaderText="单价">

<ItemTemplate>

<<a href="http://www.chinaitpower.com/Dev/Web/Asp/index.html" target="_blank">asp</a>:Label ID="UnitPrice" Runat="server"></<a href="http://www.chinaitpower.com/Dev/Web/Asp/index.html" target="_blank">asp</a>:Label>

</ItemTemplate>

</<a href="http://www.chinaitpower.com/Dev/Web/Asp/index.html" target="_blank">asp</a>:TemplateColumn>

<<a href="http://www.chinaitpower.com/Dev/Web/Asp/index.html" target="_blank">asp</a>:TemplateColumn HeaderText="数量">

<ItemTemplate>

<<a href="http://www.chinaitpower.com/Dev/Web/Asp/index.html" target="_blank">asp</a>:Label ID="Quantity" Runat="server"></<a href="http://www.chinaitpower.com/Dev/Web/Asp/index.html" target="_blank">asp</a>:Label>

</ItemTemplate>

</<a href="http://www.chinaitpower.com/Dev/Web/Asp/index.html" target="_blank">asp</a>:TemplateColumn>

<<a href="http://www.chinaitpower.com/Dev/Web/Asp/index.html" target="_blank">asp</a>:TemplateColumn HeaderText="折扣">

<ItemTemplate>

<<a href="http://www.chinaitpower.com/Dev/Web/Asp/index.html" target="_blank">asp</a>:Label ID="Discount" Runat="server"></<a href="http://www.chinaitpower.com/Dev/Web/Asp/index.html" target="_blank">asp</a>:Label>

</ItemTemplate>

</<a href="http://www.chinaitpower.com/Dev/Web/Asp/index.html" target="_blank">asp</a>:TemplateColumn>

<<a href="http://www.chinaitpower.com/Dev/Web/Asp/index.html" target="_blank">asp</a>:TemplateColumn HeaderText="总计">

<ItemTemplate>

<<a href="http://www.chinaitpower.com/Dev/Web/Asp/index.html" target="_blank">asp</a>:Label ID="lblTotal" Runat="server"></<a href="http://www.chinaitpower.com/Dev/Web/Asp/index.html" target="_blank">asp</a>:Label>

</ItemTemplate>

</<a href="http://www.chinaitpower.com/Dev/Web/Asp/index.html" target="_blank">asp</a>:TemplateColumn>

</Columns>

</<a href="http://www.chinaitpower.com/Dev/Web/Asp/index.html" target="_blank">asp</a>:DataGrid>

</form>

</body>

</HTML>

AddDataSetColumn.aspx.vb

Imports System.Web.UI.WebControls

Public Class AddDataSetColumn

Inherits System.Web.UI.Page

#Region " Web 窗体设计器生成的代码 "

'该调用是 Web 窗体设计器所必需的。

<System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()

End Sub

Protected WithEvents DataGrid1 As System.Web.UI.WebControls.DataGrid

'注意: 以下占位符声明是 Web 窗体设计器所必需的。

'不要删除或移动它。

Private designerPlaceholderDeclaration As System.Object

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

'CODEGEN: 此方法调用是 Web 窗体设计器所必需的

'不要使用代码编辑器修改它。

InitializeComponent()

End Sub

#End Region

Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

Dim strCnn As String = "Data Source=.\NetSDK; Initial Catalog=Northwind;User ID=sa;Password=;"

Dim oCn As New System.Data.SqlClient.SqlConnection(strCnn)

Dim strSql As System.String = "select * from [Order Details]"

Dim ds As System.Data.DataSet = New System.Data.DataSet

oCn.Open()

Dim da As System.Data.SqlClient.SqlDataAdapter = New System.Data.SqlClient.SqlDataAdapter(strSql, oCn)

' 可以直接使用SQL语句实现，这个方法可以直接绑定，不需要用模板即可

' cmd.CommandText = "select *,UnitPrice * Quantity *(1- Discount) as Total from [Order Details]"

' 我们使用另外一种方法，在DataGrid绑定之前为DataSet添加一个列

da.Fill(ds, "DS")

Dim dvwGrid As DataView = ds.Tables(0).DefaultView

DataGrid1.DataSource = dvwGrid

DataGrid1.DataBind()

oCn.Close()

oCn.Dispose()

End Sub

Private Sub DataGrid1_ItemDataBound(ByVal sender As Object, ByVal e As DataGridItemEventArgs) _

Handles DataGrid1.ItemDataBound

Dim elemType As ListItemType = e.Item.ItemType

If (elemType = ListItemType.Item Or elemType = ListItemType.AlternatingItem) Then

'把DataItem转换回DataRowView对象

Dim myDataRowView As DataRowView = CType(e.Item.DataItem, DataRowView)

Dim myDataRow As DataRow = myDataRowView.Row

CType(e.Item.Cells(0).FindControl("OrderID"), Label).Text = myDataRow("OrderID")

CType(e.Item.Cells(1).FindControl("ProductID"), Label).Text = myDataRow("ProductID")

CType(e.Item.Cells(2).FindControl("UnitPrice"), Label).Text = myDataRow("UnitPrice")

CType(e.Item.Cells(3).FindControl("Quantity"), Label).Text = myDataRow("Quantity")

CType(e.Item.Cells(4).FindControl("Discount"), Label).Text = myDataRow("Discount")

Dim dblPrice As Double = Double.Parse(myDataRow("UnitPrice"))

Dim intQuantity As Integer = Int32.Parse(myDataRow("Quantity"))

Dim intDiscount As Double = Double.Parse(myDataRow("Discount"))

Dim nTotal As String = String.Format("{0:C}", dblPrice * (1 - intDiscount) * intQuantity)

CType(e.Item.Cells(5).FindControl("lblTotal"), Label).Text = nTotal

End If

End Sub

End Class

分享到

微信分享
新浪微博
QQ好友
QQ空间

上一篇在DotNet里面利用XML

下一篇用ASP.NET还原与恢复SQL Server数据库