本文整理汇总了VB.NET中System.Web.UI.DataSourceView.ExecuteSelect方法的典型用法代码示例。如果您正苦于以下问题：VB.NET DataSourceView.ExecuteSelect方法的具体用法？VB.NET DataSourceView.ExecuteSelect怎么用？VB.NET DataSourceView.ExecuteSelect使用的例子？那么, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类System.Web.UI.DataSourceView的用法示例。
在下文中一共展示了DataSourceView.ExecuteSelect方法的1个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的VB.NET代码示例。
示例1: ExecuteSelect
' Get data from the underlying data source.
' Build and return a DataView, regardless of mode.
Protected Overrides Function ExecuteSelect(selectArgs As DataSourceSelectArguments) _
As System.Collections.IEnumerable
Dim dataList As IEnumerable = Nothing
' Open the .csv file.
If File.Exists(Me.SourceFile) Then
Dim data As New DataTable()
' Open the file to read from.
Dim sr As StreamReader = File.OpenText(Me.SourceFile)
Try
' Parse the line
Dim dataValues() As String
Dim col As DataColumn
' Do the following to add schema.
dataValues = sr.ReadLine().Split(","c)
' For each token in the comma-delimited string, add a column
' to the DataTable schema.
Dim token As String
For Each token In dataValues
col = New DataColumn(token, System.Type.GetType("System.String"))
data.Columns.Add(col)
Next token
' Do not add the first row as data if the CSV file includes column names.
If Not IncludesColumnNames Then
data.Rows.Add(CopyRowData(dataValues, data.NewRow()))
End If
' Do the following to add data.
Dim s As String
Do
s = sr.ReadLine()
If Not s Is Nothing Then
dataValues = s.Split(","c)
data.Rows.Add(CopyRowData(dataValues, data.NewRow()))
End If
Loop Until s Is Nothing
Finally
sr.Close()
End Try
data.AcceptChanges()
Dim dataView As New DataView(data)
If Not selectArgs.SortExpression Is String.Empty Then
dataView.Sort = selectArgs.SortExpression
End If
dataList = dataView
Else
Throw New System.Configuration.ConfigurationErrorsException("File not found, " + Me.SourceFile)
End If
If dataList is Nothing Then
Throw New InvalidOperationException("No data loaded from data source.")
End If
Return dataList
End Function 'ExecuteSelect
Private Function CopyRowData([source]() As String, target As DataRow) As DataRow
Try
Dim i As Integer
For i = 0 To [source].Length - 1
target(i) = [source](i)
Next i
Catch iore As IndexOutOfRangeException
' There are more columns in this row than
' the original schema allows. Stop copying
' and return the DataRow.
Return target
End Try
Return target
End Function 'CopyRowData