DataTable 的原始输出格式可以透过DefaultView 属性来取得， DefaultView 属性本身就是DataView 对象；我们可以设定DefaultView 的属性来指定DataTable 的显示格式。如果预设的一个DefaultView 这个DataView 对象无法满足你的需求，我们还可以产生多个DataView 对象来制定多个数据显示外观。下表列出了DataView 对象的常用的属性及方法：


排序数据
    要排序数据，可以使用DataView 对象的Sort 属性。Sort 属性是以字段做为排序的依据，其设定语法如下所示：

DataView.Sort="字段一ASC|DESC [,...字段N ASC|DESC]"

    下列范例指定了Members 这个DataTable 的DefaultView 的Sort 属性以UserId 做升幂排序：

<%@Import Namespace=System.Data.ADO%>
<%@Import Namespace=System.Data%>
<Script Language="VB" Runat="Server">
Sub Page_Load(Sender As Object, e As EventArgs)
Dim strConStr As String = "Provider=Microsoft.Jet.OLEDB.4.0;" & _
"Data Source=C:InetPubwwwrootCRCH05MyWeb.mdb"
Dim strComStr As String = "Select * From Members"
Dim dscA As ADODataSetCommand = New ADODataSetCommand(strComStr,
strConStr)
Dim dsDataSet As DataSet = New DataSet()
dscA.FillDataSet(dsDataSet, "Members")
Dim dtTable As DataTable = dsDataSet.Tables("Members") '为了方
便使用而宣告的别名
Dim shtR As Short
Response.Write("DataTable 中的原始资料:<br>")
For shtR=0 To dtTable.Rows.Count-1 ' 直接抓出DataTable 中的数
据
Response.Write("顺序" & (shtR+1).ToString & " " & _
dtTable.Rows(shtR)("UserId") & " ")
Next
dtTable.DefaultView.Sort="UserId Asc" '设定DefaultView 的排序
条件
Response.Write("<p>DataTable.DefaultView 的资料:<br>")
For shtR=0 To dtTable.DefaultView.Count-1 '显示DataView 整
理的资料
Response.Write("顺序" & (shtR+1).ToString & " " & _
dtTable.DefaultView(shtR)("UserId") & " ")
Next
End Sub
</SCRIPT>

筛选记录
    要筛选记录，可以使用DataView 对象的RowFilter 属性以及RowStateFilter 属性。RowFilter属性可以利用比较运算子「<」、「>」、「<=」、「>=」以及「Like」来过滤记录中的数据，其语法如下所示：

DataView.RowFilter = "条件叙述"

    下列范例设定DefaultView 的RowFilter 属性，只有台北县的记录会被显示出来：

<%@Import Namespace=System.Data.ADO%>
<%@Import Namespace=System.Data%>
<Script Language="VB" Runat="Server">
Sub Page_Load(Sender As Object, e As EventArgs)
Dim strConStr As String = "Provider=Microsoft.Jet.OLEDB.4.0;" & _
"Data Source=C:InetPubwwwrootCRCH05MyWeb.mdb"
Dim strComStr As String = "Select * From Members"
Dim dscA As ADODataSetCommand = New ADODataSetCommand(strComStr,
strConStr)
Dim dsDataSet As DataSet = New DataSet()
dscA.FillDataSet(dsDataSet, "Members")
Dim dtTable As DataTable = dsDataSet.Tables("Members")
Dim shtR As Short
dtTable.DefaultView.RowFilter ="UserAdd Like '台北县%'"
Response.Write("住台北县的总共有" & _
dtTable.DefaultView.Count.ToString & " 人, 分别是: ")
For shtR=0 To dtTable.DefaultView.Count-1 '显示DataView 整理的
资料
Response.Write(dtTable.DefaultView(shtR)("UserName") & " ")
Next
End Sub
</SCRIPT>

    而RowStateFilter 属性则是以记录的状态来作筛选的条件。其使用语法如下所视：

DataView.RowStateFilter = DataViewState.状态

可过滤的字段的状态如下表所示：

下列范例中删除了一笔记录，并且利用RowStateFilter 属性显示这笔被删除的记录：

<%@Import Namespace=System.Data.ADO%>
<%@Import Namespace=System.Data%>
<Script Language="VB" Runat="Server">
Sub Page_Load(Sender As Object, e As EventArgs)
Dim strConStr As String = "Provider=Microsoft.Jet.OLEDB.4.0;" & _
"Data Source=C:InetPubwwwrootCRCH05MyWeb.mdb"
Dim strComStr As String = "Select * From Members"
Dim dscA As ADODataSetCommand = New ADODataSetCommand(strComStr,
strConStr)
Dim dsDataSet As DataSet = New DataSet()
dscA.FillDataSet(dsDataSet, "Members")
Dim dtTable As DataTable = dsDataSet.Tables("Members") '为了方便使用
dtTable.Rows(0).Delete() '删除DataTable 中的第一笔记录
Dim shtR As Short
dtTable.DefaultView.RowStateFilter = DataViewRowState.Deleted
Response.Write("被删除的使用者总共有" & _
dtTable.DefaultView.Count.ToString & " 人, 分别是: ")
For shtR=0 To dtTable.DefaultView.Count-1 '显示DataView 整理的资
料
Response.Write(dtTable.DefaultView(shtR)("UserName") & " ")
Next
End Sub
</SCRIPT>

    上述程序虽然删除了DataTable 中的第一笔记录，除非使用DataSetCommand 对象的Update方法将所作的更动更新回数据源，否则是不会影响数据源的数据状态。

搜寻数据
    要搜寻DataTable 里面的数据，可以利用DataView 的Find 方法。如果Find 方法有找到符合的数据，则传回数据所在记录的Index 值；倘若没找到则传回-1。其使用语法如下所示：

变数= DataView.Find("要搜寻的字符串")

    列范例可以在文字输入盒中输入数据，按下确定后利用Find 方法找寻使用者的数据，并显示数据所在记录的Index 值：

<%@Import Namespace=System.Data.ADO%>
<%@Import Namespace=System.Data%>
<Form Id="Form1" Runat="Server">
请输入所要查询的数据:
<Input Type="Text" Runat="Server" Id="Text1">
<Button Id="Button1" Runat="Server" OnServerClick="Button1_Click">
查询</Button>
</Form>
<Span Id="Sp1" Runat="Server"/>
<Script Language="VB" Runat="Server">
Sub Button1_Click(Sender As Object, e As EventArgs)
Dim strConStr As String = "Provider=Microsoft.Jet.OLEDB.4.0;" &
_
"Data Source=C:InetPubwwwrootCRCH05MyWeb.mdb"
Dim strComStr As String = "Select * From Members"
Dim dscA As ADODataSetCommand = New ADODataSetCommand(strComStr,
strConStr)
Dim dsDataSet As DataSet = New DataSet()
dscA.FillDataSet(dsDataSet, "Members")
Dim dtTable As DataTable = dsDataSet.Tables("Members")
dtTable.DefaultView.Sort="UserId" '必须要指定Sort 属性才可以搜
寻
Dim shtR As Short
shtR=dtTable.DefaultView.Find(Text1.Value) '传回符合记录的
Index 值
If shtR = -1 Then '如果没找到就传回-1
Sp1.InnerText="没找到您所输入的数据"
Else
Sp1.InnerText="您所要找的资料在第" & shtR.ToString & " 笔记录"
End if
End Sub
</SCRIPT>

产生自订的DataView 对象
    如果一个DataView 对象不能满足我们的需求，我们还可以建立多个DataView 对象来制定数据的显示格式。其宣告语法如下所示：

Dim 变量As DataView = New DataView(数据表)

    下列范例中从同一个DataTable 中产生了两个自订的DataView 对象，并指定不同的数据排序方式：

<%@Import Namespace=System.Data.ADO%>
<%@Import Namespace=System.Data%>
<Script Language="VB" Runat="Server">
Sub Page_Load(Sender As Object, e As EventArgs)
Dim strConStr As String = "Provider=Microsoft.Jet.OLEDB.4.0;" & _
"Data Source=C:InetPubwwwrootCRCH05MyWeb.mdb"
Dim strComStr As String = "Select * From Members"
Dim dscA As ADODataSetCommand = New ADODataSetCommand(strComStr,
strConStr)
Dim dsDataSet As DataSet = New DataSet()
dscA.FillDataSet(dsDataSet, "Members")
Dim dv1st As DataView = New DataView(dsDataSet.Tables(0))
Dim dv2nd As DataView = New DataView(dsDataSet.Tables(0))
dv1st.Sort = "UserId ASC" '指定依UserId 由小排到大的配置
dv2nd.Sort = "UserId DESC" '指定依UserId 由大排到小的配置
Dim shtR As Short
Response.Write("dv1st 指定依UserId 由小排到大的配置:<br>")
For shtR=0 To dv1st.Count-1 '显示DataView 整理的资料
Response.Write("顺序" & (shtR+1).ToString & " " & _
" -> " & dv1st(shtR)("UserId") & " ")
Next
Response.Write("<p>dv2nd 指定依UserId 由大排到小的配置:<br>")
For shtR=0 To dv2nd.Count-1 '显示DataView 整理的资料
Response.Write("顺序" & (shtR+1).ToString & " " & _
" -> " & dv2nd(shtR)("UserId") & " ")
Next
End Sub
</SCRIPT>

    我们可以将DataView 直接当成DataTable 来使用，因为DataView 的数据来源还是DataTable对象，所以我们对DataView 对象所执行的任何操作都会影响原来的DataTable 中的数据。下列范例显示修改DataView 中的数据对原来DataTable 对象的影响：

<%@Import Namespace=System.Data.ADO%>
<%@Import Namespace=System.Data%>
<Script Language="VB" Runat="Server">
Sub Page_Load(Sender As Object, e As EventArgs)
Dim strConStr As String = "Provider=Microsoft.Jet.OLEDB.4.0;" & _
"Data Source=C:InetPubwwwrootCRCH05MyWeb.mdb"
Dim strComStr As String = "Select * From Members"
Dim dscA As ADODataSetCommand = New ADODataSetCommand(strComStr,
strConStr)
Dim dsDataSet As DataSet = New DataSet()
Dim shtR As Short
dscA.FillDataSet(dsDataSet, "Members")
Dim dv1st As DataView = New DataView(dsDataSet.Tables(0))
Dim dv2nd As DataView = New DataView(dsDataSet.Tables(0))
dv1st.Sort = "UserId ASC" '指定依UserId 由小排到大的配置
dv2nd.Sort = "UserId DESC" '指定依UserId 由大排到小的配置
dv1st(0)("UserTEL")="1234567890" '修改其中一个DataView 的内容
Response.Write("观察原来DataTable 中的数据是否有改变:<br>")
For shtR=0 To dsDataSet.Tables(0).Rows.Count-1 'DataTable 中的原来数
据
Response.Write("顺序" & (shtR+1).ToString & " " & _
" -> " & dsDataSet.Tables(0).Rows(shtR)("UserId") & "
")
Next
For shtR=0 To dsDataSet.Tables(0).Rows.Count-1 '显示UserTel 字段的资
料
Response.Write("<br>内容" & (shtR+1).ToString & " " & _
" -> " & dsDataSet.Tables(0).Rows(shtR)("UserTel"))
Next
Response.Write("<p>dv1st 指定依UserId 由小排到大的配置:<br>")
For shtR=0 To dv1st.Count-1 '显示DataView 整理的资料
Response.Write("顺序" & (shtR+1).ToString & " " & _
" -> " & dv1st(shtR)("UserId") & " ")
Next
For shtR=0 To dv1st.Count-1 '显示UserTel 字段的资料
Response.Write("<br>内容" & (shtR+1).ToString & " " & _
" -> " & dv1st(shtR)("UserTel"))
Next
Response.Write("<p>dv2nd 指定依UserId 由大排到小的配置:<br>")
For shtR=0 To dv2nd.Count-1 '显示DataView 整理的资料
Response.Write("顺序" & (shtR+1).ToString & " " & _
" -> " & dv2nd(shtR)("UserId") & " ")
Next
For shtR=0 To dv2nd.Count-1 '显示UserTEL 字段的资料
Response.Write("<br>内容" & (shtR+1).ToString & " " & _
" -> " & dv2nd(shtR)("UserTEL"))
Next
End Sub
</SCRIPT>