本文整理汇总了VB.NET中System.Windows.Forms.ListView.Groups属性的典型用法代码示例。如果您正苦于以下问题:VB.NET ListView.Groups属性的具体用法?VB.NET ListView.Groups怎么用?VB.NET ListView.Groups使用的例子?那么, 这里精选的属性代码示例或许可以为您提供帮助。您也可以进一步了解该属性所在类System.Windows.Forms.ListView
的用法示例。
在下文中一共展示了ListView.Groups属性的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: ListViewGroupsExample
' 导入命名空间
Imports System.Collections
Imports System.Windows.Forms
Public Class ListViewGroupsExample
Inherits Form
Private myListView As ListView
' Determine whether Windows XP or a later
' operating system is present.
Private isRunningXPOrLater As Boolean = _
OSFeature.Feature.IsPresent(OSFeature.Themes)
' Declare a Hashtable array in which to store the groups.
Private groupTables() As Hashtable
' Declare a variable to store the current grouping column.
Private groupColumn As Integer = 0
Public Sub New()
' Initialize myListView.
myListView = New ListView()
myListView.Dock = DockStyle.Fill
myListView.View = View.Details
myListView.Sorting = SortOrder.Ascending
' Create and initialize column headers for myListView.
Dim columnHeader0 As New ColumnHeader()
columnHeader0.Text = "Title"
columnHeader0.Width = -1
Dim columnHeader1 As New ColumnHeader()
columnHeader1.Text = "Author"
columnHeader1.Width = -1
Dim columnHeader2 As New ColumnHeader()
columnHeader2.Text = "Year"
columnHeader2.Width = -1
' Add the column headers to myListView.
myListView.Columns.AddRange( New ColumnHeader() _
{columnHeader0, columnHeader1, columnHeader2} )
' Add a handler for the ColumnClick event.
AddHandler myListView.ColumnClick, AddressOf myListView_ColumnClick
' Create items and add them to myListView.
Dim item0 As New ListViewItem( New String() _
{"Programming Windows", _
"Petzold, Charles", _
"1998"} )
Dim item1 As New ListViewItem( New String() _
{"Code: The Hidden Language of Computer Hardware and Software", _
"Petzold, Charles", _
"2000"} )
Dim item2 As New ListViewItem( New String() _
{"Programming Windows with C#", _
"Petzold, Charles", _
"2001"} )
Dim item3 As New ListViewItem( New String() _
{"Coding Techniques for Microsoft Visual Basic .NET", _
"Connell, John", _
"2001"} )
Dim item4 As New ListViewItem( New String() _
{"C# for Java Developers", _
"Jones, Allen / Freeman, Adam", _
"2002"} )
Dim item5 As New ListViewItem( New String() _
{"Microsoft .NET XML Web Services Step by Step", _
"Jones, Allen / Freeman, Adam", _
"2002"} )
myListView.Items.AddRange( _
New ListViewItem() {item0, item1, item2, item3, item4, item5})
If isRunningXPOrLater
' Create the groupsTable array and populate it with one
' hash table for each column.
groupTables = New Hashtable(myListView.Columns.Count) {}
Dim column As Integer
For column = 0 To myListView.Columns.Count - 1
' Create a hash table containing all the groups
' needed for a single column.
groupTables(column) = CreateGroupsTable(column)
Next column
' Start with the groups created for the Title column.
SetGroups(0)
End If
' Initialize the form.
Me.Controls.Add(myListView)
Me.Size = New System.Drawing.Size(550, 330)
Me.Text = "ListView Groups Example"
End Sub
<STAThread()> _
Shared Sub Main()
Application.EnableVisualStyles()
Application.Run(New ListViewGroupsExample())
End Sub
' Groups the items using the groups created for the clicked
' column.
Private Sub myListView_ColumnClick( _
sender As Object, e As ColumnClickEventArgs)
' Set the sort order to ascending when changing
' column groups; otherwise, reverse the sort order.
If myListView.Sorting = SortOrder.Descending OrElse _
isRunningXPOrLater And e.Column <> groupColumn Then
myListView.Sorting = SortOrder.Ascending
Else
myListView.Sorting = SortOrder.Descending
End If
groupColumn = e.Column
' Set the groups to those created for the clicked column.
If isRunningXPOrLater Then
SetGroups(e.Column)
End If
End Sub
' Sets myListView to the groups created for the specified column.
Private Sub SetGroups(column As Integer)
' Remove the current groups.
myListView.Groups.Clear()
' Retrieve the hash table corresponding to the column.
Dim groups As Hashtable = CType(groupTables(column), Hashtable)
' Copy the groups for the column to an array.
Dim groupsArray(groups.Count - 1) As ListViewGroup
groups.Values.CopyTo(groupsArray, 0)
' Sort the groups and add them to myListView.
Array.Sort(groupsArray, New ListViewGroupSorter(myListView.Sorting))
myListView.Groups.AddRange(groupsArray)
' Iterate through the items in myListView, assigning each
' one to the appropriate group.
Dim item As ListViewItem
For Each item In myListView.Items
' Retrieve the subitem text corresponding to the column.
Dim subItemText As String = item.SubItems(column).Text
' For the Title column, use only the first letter.
If column = 0 Then
subItemText = subItemText.Substring(0, 1)
End If
' Assign the item to the matching group.
item.Group = CType(groups(subItemText), ListViewGroup)
Next item
End Sub
' Creates a Hashtable object with one entry for each unique
' subitem value (or initial letter for the parent item)
' in the specified column.
Private Function CreateGroupsTable(column As Integer) As Hashtable
' Create a Hashtable object.
Dim groups As New Hashtable()
' Iterate through the items in myListView.
Dim item As ListViewItem
For Each item In myListView.Items
' Retrieve the text value for the column.
Dim subItemText As String = item.SubItems(column).Text
' Use the initial letter instead if it is the first column.
If column = 0 Then
subItemText = subItemText.Substring(0, 1)
End If
' If the groups table does not already contain a group
' for the subItemText value, add a new group using the
' subItemText value for the group header and Hashtable key.
If Not groups.Contains(subItemText) Then
groups.Add( subItemText, New ListViewGroup(subItemText, _
HorizontalAlignment.Left) )
End If
Next item
' Return the Hashtable object.
Return groups
End Function 'CreateGroupsTable
' Sorts ListViewGroup objects by header value.
Private Class ListViewGroupSorter
Implements IComparer
Private order As SortOrder
' Stores the sort order.
Public Sub New(theOrder As SortOrder)
order = theOrder
End Sub
' Compares the groups by header value, using the saved sort
' order to return the correct value.
Public Function Compare(x As Object, y As Object) As Integer _
Implements IComparer.Compare
Dim result As Integer = String.Compare( _
CType(x, ListViewGroup).Header, _
CType(y, ListViewGroup).Header )
If order = SortOrder.Ascending Then
Return result
Else
Return -result
End If
End Function 'Compare
End Class
End Class