collapsible listview - vb.net

Question

i want to make the listview control collapsible to the groups alone. Like in Vista's My Computer, where only the group names are shown and then we click on the group to expand it.
I am using VB.NET 3.5

Answer 1

Check this out:
Collapsible ListViewGroup
and maybe:
Add Group Collapse Behavior on a Listview Control
Both are written in C# but of course you can still use them in VB.NET projects.
You can only use these on Vista and later.

Answer 2

There is definitely no way to do this with the bog-standard VB.NET ListView control. In fact, it doesn't seem possible even with an ObjectListView, which is my usual port of call when I encounter a ListView limitation.
You could either:
Roll your own control
Switch to a TreeView
Give up
I think that number 2 is the best option in your case, as it's not that difficult. Number one is overkill and takes a lot of time. If you have a GUI layer that is tightly coupled to your logic and database layers, it may be a lot harder to convert to a TreeView. Or, you could just be using the other ListView views. (In the latter case, an TreeListView from the same FOSS project could be the way to go - it is GPL though.)
It may be easier just to kill this feature - I don't think it would be critical.

Answer 3

Here's an old article that extends the list view:
http://www.codeproject.com/KB/list/GroupListView.aspx?msg=1135144
Here's a sample that does what I think you want with a GridView, panel and the Collapsible Panel Extender
You could also switch to the AJAX control toolkit Accordian control.

Answer 4

I have managed to achieve this by looking at what you guys have posted around here and this is how my code looks like.
Imports System.Collections.Generic
Imports System.Text
Imports System.Windows.Forms
Imports System.ComponentModel
Imports System.Runtime.InteropServices
Imports System.Reflection
Public Class ListViewCollapsible
Inherits ListView
Private Const LVM_FIRST As Integer = &H1000
' ListView messages
Private Const LVM_SETGROUPINFO As Integer = (LVM_FIRST + 147)
' ListView messages Setinfo on Group
Private Const WM_LBUTTONUP As Integer = &H202
' Windows message left button
Private Delegate Sub CallBackSetGroupState(lstvwgrp As ListViewGroup, state As ListViewGroupState)
Private Delegate Sub CallbackSetGroupString(lstvwgrp As ListViewGroup, value As String)
''' <summary>
''' Sends the specified message to a window or windows. The SendMessage function calls the window procedure for the specified window and does not return until the window procedure has processed the message.
''' To send a message and return immediately, use the SendMessageCallback or SendNotifyMessage function. To post a message to a thread's message queue and return immediately, use the PostMessage or PostThreadMessage function.
''' </summary>
''' <param name="hWnd">
''' [in] Handle to the window whose window procedure will receive the message.
''' If this parameter is HWND_BROADCAST, the message is sent to all top-level windows in the system, including disabled or invisible unowned windows, overlapped windows, and pop-up windows; but the message is not sent to child windows.
''' Microsoft Windows Vista and later. Message sending is subject to User Interface Privilege Isolation (UIPI). The thread of a process can send messages only to message queues of threads in processes of lesser or equal integrity level.
''' </param>
''' <param name="Msg">[in] Specifies the message to be sent.</param>
''' <param name="wParam">[in] Specifies additional message-specific information.</param>
''' <param name="lParam">[in] Type of LVGROUP, Specifies additional message-specific information.</param>
''' <returns>
''' Microsoft Windows Vista and later. When a message is blocked by UIPI the last error, retrieved with GetLastError, is set to 5 (access denied).
''' Applications that need to communicate using HWND_BROADCAST should use the RegisterWindowMessage function to obtain a unique message for inter-application communication.
''' The system only does marshalling for system messages (those in the range 0 to (WM_USER-1)). To send other messages (those >= WM_USER) to another process, you must do custom marshalling.
''' If the specified window was created by the calling thread, the window procedure is called immediately as a subroutine. If the specified window was created by a different thread, the system switches to that thread and calls the appropriate window procedure. Messages sent between threads are processed only when the receiving thread executes message retrieval code. The sending thread is blocked until the receiving thread processes the message. However, the sending thread will process incoming nonqueued messages while waiting for its message to be processed. To prevent this, use SendMessageTimeout with SMTO_BLOCK set. For more information on nonqueued messages, see Nonqueued Messages.
''' Windows 95/98/Me: SendMessageW is supported by the Microsoft Layer for Unicode (MSLU). To use this, you must add certain files to your application, as outlined in Microsoft Layer for Unicode on Windows 95/98/Me Systems.
''' </returns>
<DllImport("User32.dll"), Description("Sends the specified message to a window or windows. The SendMessage function calls the window procedure for the specified window and does not return until the window procedure has processed the message. To send a message and return immediately, use the SendMessageCallback or SendNotifyMessage function. To post a message to a thread's message queue and return immediately, use the PostMessage or PostThreadMessage function.")> _
Private Shared Function SendMessage(hWnd As IntPtr, Msg As Integer, wParam As Integer, lParam As IntPtr) As Integer
End Function
Private Shared Function GetGroupID(lstvwgrp As ListViewGroup) As System.Nullable(Of Integer)
Dim rtnval As System.Nullable(Of Integer) = Nothing
Dim GrpTp As Type = lstvwgrp.[GetType]()
If GrpTp IsNot Nothing Then
Dim pi As PropertyInfo = GrpTp.GetProperty("ID", BindingFlags.NonPublic Or BindingFlags.Instance)
If pi IsNot Nothing Then
Dim tmprtnval As Object = pi.GetValue(lstvwgrp, Nothing)
If tmprtnval IsNot Nothing Then
rtnval = CInt(tmprtnval)
End If
End If
End If
Return rtnval
End Function
Private Shared Sub setGrpState(lstvwgrp As ListViewGroup, state As ListViewGroupState)
If Environment.OSVersion.Version.Major < 6 Then
'Only Vista and forward allows collaps of ListViewGroups
Return
End If
If lstvwgrp Is Nothing OrElse lstvwgrp.ListView Is Nothing Then
Return
End If
If lstvwgrp.ListView.InvokeRequired Then
lstvwgrp.ListView.Invoke(New CallBackSetGroupState(AddressOf setGrpState), lstvwgrp, state)
Else
Dim GrpId As System.Nullable(Of Integer) = GetGroupID(lstvwgrp)
Dim gIndex As Integer = lstvwgrp.ListView.Groups.IndexOf(lstvwgrp)
Dim group As New LVGROUP
group.CbSize = Marshal.SizeOf(group)
group.State = state
group.Mask = ListViewGroupMask.State
Dim ip As IntPtr = IntPtr.Zero
Try
If GrpId IsNot Nothing Then
group.IGroupId = GrpId.Value
ip = Marshal.AllocHGlobal(group.CbSize)
Marshal.StructureToPtr(group, ip, False)
SendMessage(lstvwgrp.ListView.Handle, LVM_SETGROUPINFO, GrpId.Value, ip)
SendMessage(lstvwgrp.ListView.Handle, LVM_SETGROUPINFO, GrpId.Value, ip)
Else
group.IGroupId = gIndex
ip = Marshal.AllocHGlobal(group.CbSize)
Marshal.StructureToPtr(group, ip, False)
SendMessage(lstvwgrp.ListView.Handle, LVM_SETGROUPINFO, gIndex, ip)
SendMessage(lstvwgrp.ListView.Handle, LVM_SETGROUPINFO, gIndex, ip)
End If
lstvwgrp.ListView.Refresh()
Finally
If (ip <> IntPtr.Zero) Then Marshal.FreeHGlobal(ip)
End Try
End If
End Sub
Private Shared Sub setGrpFooter(lstvwgrp As ListViewGroup, footer As String)
If Environment.OSVersion.Version.Major < 6 Then
'Only Vista and forward allows footer on ListViewGroups
Return
End If
If lstvwgrp Is Nothing OrElse lstvwgrp.ListView Is Nothing Then
Return
End If
If lstvwgrp.ListView.InvokeRequired Then
lstvwgrp.ListView.Invoke(New CallbackSetGroupString(AddressOf setGrpFooter), lstvwgrp, footer)
Else
Dim GrpId As System.Nullable(Of Integer) = GetGroupID(lstvwgrp)
Dim gIndex As Integer = lstvwgrp.ListView.Groups.IndexOf(lstvwgrp)
Dim group As New LVGROUP
group.CbSize = Marshal.SizeOf(group)
group.PszFooter = footer
group.Mask = ListViewGroupMask.Footer
Dim ip As IntPtr = IntPtr.Zero
Try
If GrpId IsNot Nothing Then
group.IGroupId = GrpId.Value
ip = Marshal.AllocHGlobal(group.CbSize)
Marshal.StructureToPtr(group, ip, False)
SendMessage(lstvwgrp.ListView.Handle, LVM_SETGROUPINFO, GrpId.Value, ip)
Else
group.IGroupId = gIndex
ip = Marshal.AllocHGlobal(group.CbSize)
Marshal.StructureToPtr(group, ip, False)
SendMessage(lstvwgrp.ListView.Handle, LVM_SETGROUPINFO, gIndex, ip)
End If
Finally
If (ip <> IntPtr.Zero) Then Marshal.FreeHGlobal(ip)
End Try
End If
End Sub
Public Sub SetGroupState(state As ListViewGroupState)
For Each lvg As ListViewGroup In Me.Groups
setGrpState(lvg, state)
Next
End Sub
Public Sub SetGroupState(state As ListViewGroupState, lvg As ListViewGroup)
setGrpState(lvg, state)
End Sub
Public Sub SetGroupFooter(lvg As ListViewGroup, footerText As String)
setGrpFooter(lvg, footerText)
End Sub
Protected Overrides Sub WndProc(ByRef m As Message)
If m.Msg = WM_LBUTTONUP Then
MyBase.DefWndProc(m)
End If
MyBase.WndProc(m)
End Sub
End Class
''' <summary>
''' LVGROUP StructureUsed to set and retrieve groups.
''' </summary>
''' <example>
''' LVGROUP myLVGROUP = new LVGROUP();
''' myLVGROUP.CbSize // is of managed type uint
''' myLVGROUP.Mask // is of managed type uint
''' myLVGROUP.PszHeader // is of managed type string
''' myLVGROUP.CchHeader // is of managed type int
''' myLVGROUP.PszFooter // is of managed type string
''' myLVGROUP.CchFooter // is of managed type int
''' myLVGROUP.IGroupId // is of managed type int
''' myLVGROUP.StateMask // is of managed type uint
''' myLVGROUP.State // is of managed type uint
''' myLVGROUP.UAlign // is of managed type uint
''' myLVGROUP.PszSubtitle // is of managed type IntPtr
''' myLVGROUP.CchSubtitle // is of managed type uint
''' myLVGROUP.PszTask // is of managed type string
''' myLVGROUP.CchTask // is of managed type uint
''' myLVGROUP.PszDescriptionTop // is of managed type string
''' myLVGROUP.CchDescriptionTop // is of managed type uint
''' myLVGROUP.PszDescriptionBottom // is of managed type string
''' myLVGROUP.CchDescriptionBottom // is of managed type uint
''' myLVGROUP.ITitleImage // is of managed type int
''' myLVGROUP.IExtendedImage // is of managed type int
''' myLVGROUP.IFirstItem // is of managed type int
''' myLVGROUP.CItems // is of managed type IntPtr
''' myLVGROUP.PszSubsetTitle // is of managed type IntPtr
''' myLVGROUP.CchSubsetTitle // is of managed type IntPtr
''' </example>
''' <remarks>
''' The LVGROUP structure was created by Paw Jershauge
''' Created: Jan. 2008.
''' The LVGROUP structure code is based on information from Microsoft's MSDN2 website.
''' The structure is generated via an automated converter and is as is.
''' The structure may or may not hold errors inside the code, so use at own risk.
''' Reference url: http://msdn.microsoft.com/en-us/library/bb774769(VS.85).aspx
''' </remarks>
<StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Unicode), Description("LVGROUP StructureUsed to set and retrieve groups.")> _
Public Structure LVGROUP
''' <summary>
''' Size of this structure, in bytes.
''' </summary>
<Description("Size of this structure, in bytes.")> _
Public CbSize As Integer
''' <summary>
''' Mask that specifies which members of the structure are valid input. One or more of the following values:LVGF_NONENo other items are valid.
''' </summary>
<Description("Mask that specifies which members of the structure are valid input. One or more of the following values:LVGF_NONE No other items are valid.")> _
Public Mask As ListViewGroupMask
''' <summary>
''' Pointer to a null-terminated string that contains the header text when item information is being set. If group information is being retrieved, this member specifies the address of the buffer that receives the header text.
''' </summary>
<Description("Pointer to a null-terminated string that contains the header text when item information is being set. If group information is being retrieved, this member specifies the address of the buffer that receives the header text.")> _
<MarshalAs(UnmanagedType.LPWStr)> _
Public PszHeader As String
''' <summary>
''' Size in TCHARs of the buffer pointed to by the pszHeader member. If the structure is not receiving information about a group, this member is ignored.
''' </summary>
<Description("Size in TCHARs of the buffer pointed to by the pszHeader member. If the structure is not receiving information about a group, this member is ignored.")> _
Public CchHeader As Integer
''' <summary>
''' Pointer to a null-terminated string that contains the footer text when item information is being set. If group information is being retrieved, this member specifies the address of the buffer that receives the footer text.
''' </summary>
<Description("Pointer to a null-terminated string that contains the footer text when item information is being set. If group information is being retrieved, this member specifies the address of the buffer that receives the footer text.")> _
<MarshalAs(UnmanagedType.LPWStr)> _
Public PszFooter As String
''' <summary>
''' Size in TCHARs of the buffer pointed to by the pszFooter member. If the structure is not receiving information about a group, this member is ignored.
''' </summary>
<Description("Size in TCHARs of the buffer pointed to by the pszFooter member. If the structure is not receiving information about a group, this member is ignored.")> _
Public CchFooter As Integer
''' <summary>
''' ID of the group.
''' </summary>
<Description("ID of the group.")> _
Public IGroupId As Integer
''' <summary>
''' Mask used with LVM_GETGROUPINFO (Microsoft Windows XP and Windows Vista) and LVM_SETGROUPINFO (Windows Vista only) to specify which flags in the state value are being retrieved or set.
''' </summary>
<Description("Mask used with LVM_GETGROUPINFO (Microsoft Windows XP and Windows Vista) and LVM_SETGROUPINFO (Windows Vista only) to specify which flags in the state value are being retrieved or set.")> _
Public StateMask As Integer
''' <summary>
''' Flag that can have one of the following values:LVGS_NORMALGroups are expanded, the group name is displayed, and all items in the group are displayed.
''' </summary>
<Description("Flag that can have one of the following values:LVGS_NORMAL Groups are expanded, the group name is displayed, and all items in the group are displayed.")> _
Public State As ListViewGroupState
''' <summary>
''' Indicates the alignment of the header or footer text for the group. It can have one or more of the following values. Use one of the header flags. Footer flags are optional. Windows XP: Footer flags are reserved.LVGA_FOOTER_CENTERReserved.
''' </summary>
<Description("Indicates the alignment of the header or footer text for the group. It can have one or more of the following values. Use one of the header flags. Footer flags are optional. Windows XP: Footer flags are reserved.LVGA_FOOTER_CENTERReserved.")> _
Public UAlign As UInteger
''' <summary>
''' Windows Vista. Pointer to a null-terminated string that contains the subtitle text when item information is being set. If group information is being retrieved, this member specifies the address of the buffer that receives the subtitle text. This element is drawn under the header text.
''' </summary>
<Description("Windows Vista. Pointer to a null-terminated string that contains the subtitle text when item information is being set. If group information is being retrieved, this member specifies the address of the buffer that receives the subtitle text. This element is drawn under the header text.")> _
Public PszSubtitle As IntPtr
''' <summary>
''' Windows Vista. Size, in TCHARs, of the buffer pointed to by the pszSubtitle member. If the structure is not receiving information about a group, this member is ignored.
''' </summary>
<Description("Windows Vista. Size, in TCHARs, of the buffer pointed to by the pszSubtitle member. If the structure is not receiving information about a group, this member is ignored.")> _
Public CchSubtitle As UInteger
''' <summary>
''' Windows Vista. Pointer to a null-terminated string that contains the text for a task link when item information is being set. If group information is being retrieved, this member specifies the address of the buffer that receives the task text. This item is drawn right-aligned opposite the header text. When clicked by the user, the task link generates an LVN_LINKCLICK notification.
''' </summary>
<Description("Windows Vista. Pointer to a null-terminated string that contains the text for a task link when item information is being set. If group information is being retrieved, this member specifies the address of the buffer that receives the task text. This item is drawn right-aligned opposite the header text. When clicked by the user, the task link generates an LVN_LINKCLICK notification.")> _
<MarshalAs(UnmanagedType.LPWStr)> _
Public PszTask As String
''' <summary>
''' Windows Vista. Size in TCHARs of the buffer pointed to by the pszTask member. If the structure is not receiving information about a group, this member is ignored.
''' </summary>
<Description("Windows Vista. Size in TCHARs of the buffer pointed to by the pszTask member. If the structure is not receiving information about a group, this member is ignored.")> _
Public CchTask As UInteger
''' <summary>
''' Windows Vista. Pointer to a null-terminated string that contains the top description text when item information is being set. If group information is being retrieved, this member specifies the address of the buffer that receives the top description text. This item is drawn opposite the title image when there is a title image, no extended image, and uAlign==LVGA_HEADER_CENTER.
''' </summary>
<Description("Windows Vista. Pointer to a null-terminated string that contains the top description text when item information is being set. If group information is being retrieved, this member specifies the address of the buffer that receives the top description text. This item is drawn opposite the title image when there is a title image, no extended image, and uAlign==LVGA_HEADER_CENTER.")> _
<MarshalAs(UnmanagedType.LPWStr)> _
Public PszDescriptionTop As String
''' <summary>
''' Windows Vista. Size in TCHARs of the buffer pointed to by the pszDescriptionTop member. If the structure is not receiving information about a group, this member is ignored.
''' </summary>
<Description("Windows Vista. Size in TCHARs of the buffer pointed to by the pszDescriptionTop member. If the structure is not receiving information about a group, this member is ignored.")> _
Public CchDescriptionTop As UInteger
''' <summary>
''' Windows Vista. Pointer to a null-terminated string that contains the bottom description text when item information is being set. If group information is being retrieved, this member specifies the address of the buffer that receives the bottom description text. This item is drawn under the top description text when there is a title image, no extended image, and uAlign==LVGA_HEADER_CENTER.
''' </summary>
<Description("Windows Vista. Pointer to a null-terminated string that contains the bottom description text when item information is being set. If group information is being retrieved, this member specifies the address of the buffer that receives the bottom description text. This item is drawn under the top description text when there is a title image, no extended image, and uAlign==LVGA_HEADER_CENTER.")> _
<MarshalAs(UnmanagedType.LPWStr)> _
Public PszDescriptionBottom As String
''' <summary>
''' Windows Vista. Size in TCHARs of the buffer pointed to by the pszDescriptionBottom member. If the structure is not receiving information about a group, this member is ignored.
''' </summary>
<Description("Windows Vista. Size in TCHARs of the buffer pointed to by the pszDescriptionBottom member. If the structure is not receiving information about a group, this member is ignored.")> _
Public CchDescriptionBottom As UInteger
''' <summary>
''' Windows Vista. Index of the title image in the control imagelist.
''' </summary>
<Description("Windows Vista. Index of the title image in the control imagelist.")> _
Public ITitleImage As Integer
''' <summary>
''' Windows Vista. Index of the extended image in the control imagelist.
''' </summary>
<Description("Windows Vista. Index of the extended image in the control imagelist.")> _
Public IExtendedImage As Integer
''' <summary>
''' Windows Vista. Read-only.
''' </summary>
<Description("Windows Vista. Read-only.")> _
Public IFirstItem As Integer
''' <summary>
''' Windows Vista. Read-only in non-owner data mode.
''' </summary>
<Description("Windows Vista. Read-only in non-owner data mode.")> _
Public CItems As IntPtr
''' <summary>
''' Windows Vista. NULL if group is not a subset. Pointer to a null-terminated string that contains the subset title text when item information is being set. If group information is being retrieved, this member specifies the address of the buffer that receives the subset title text.
''' </summary>
<Description("Windows Vista. NULL if group is not a subset. Pointer to a null-terminated string that contains the subset title text when item information is being set. If group information is being retrieved, this member specifies the address of the buffer that receives the subset title text.")> _
Public PszSubsetTitle As IntPtr
''' <summary>
''' Windows Vista. Size in TCHARs of the buffer pointed to by the pszSubsetTitle member. If the structure is not receiving information about a group, this member is ignored.
''' </summary>
<Description("Windows Vista. Size in TCHARs of the buffer pointed to by the pszSubsetTitle member. If the structure is not receiving information about a group, this member is ignored.")> _
Public CchSubsetTitle As IntPtr
End Structure
Public Enum ListViewGroupMask
None = &H0
Header = &H1
Footer = &H2
State = &H4
Align = &H8
GroupId = &H10
SubTitle = &H100
Task = &H200
DescriptionTop = &H400
DescriptionBottom = &H800
TitleImage = &H1000
ExtendedImage = &H2000
Items = &H4000
Subset = &H8000
SubsetItems = &H10000
End Enum
Public Enum ListViewGroupState
''' <summary>
''' Groups are expanded, the group name is displayed, and all items in the group are displayed.
''' </summary>
Normal = 0
''' <summary>
''' The group is collapsed.
''' </summary>
Collapsed = 1
''' <summary>
''' The group is hidden.
''' </summary>
Hidden = 2
''' <summary>
''' Version 6.00 and Windows Vista. The group does not display a header.
''' </summary>
NoHeader = 4
''' <summary>
''' Version 6.00 and Windows Vista. The group can be collapsed.
''' </summary>
Collapsible = 8
''' <summary>
''' Version 6.00 and Windows Vista. The group has keyboard focus.
''' </summary>
Focused = 16
''' <summary>
''' Version 6.00 and Windows Vista. The group is selected.
''' </summary>
Selected = 32
''' <summary>
''' Version 6.00 and Windows Vista. The group displays only a portion of its items.
''' </summary>
SubSeted = 64
''' <summary>
''' Version 6.00 and Windows Vista. The subset link of the group has keyboard focus.
''' </summary>
SubSetLinkFocused = 128
End Enum
I have tested this and it works just fine for me.
Hope it will help some of you as well.