Ordenar el contenido de un listview númericamente y mover el scroll
Lunes, 8 de Septiembre de 2008Para poder ordenar un listview tenemos la forma tradicional, mediante las propiedades:
Visual Basic:
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Dim indiceColumina as integer
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indiceColumna=5
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Listview.sorted=true
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listview.sortkey= indiceColumna
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listview.sortOrder=1 '0: ordenar ascedente, 1: ordenar descendente
El problema que la ordenación de este control es únicamente para string's, asi que si queremos ordenar por un número o identificador.
Es necesario volver a ordenar cada vez que añadimos un elemento al listview, así llamaramos cada vez que añadamos a la llamada a sistema.
Además si queremos conseguir que el primer elemento quede marcado al principio o al final. El scroll he probado de usar llamdas a sistema con LVM_SCROLL pero no funcinaba, finalmente he decidio seleccionar el elemento. Así para forzar ver el ultimo o primer elemento despues de ordenar: tan solo tendremos que hacer:
Visual Basic:
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ListView.ListItems.Item(ListView2.ListItems.Count - 1).Selected = True ' ultimo elemento
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ListView.ListItems.Item(1).Selected = True ' primer elemento del listview, ' para subir el cursor arriba
Para llamar a que se ordene despues de añadir sería así:
Visual Basic:
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'------ Mandamos a ordenar el listview. --------
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sOrder = 0 ' orden descendente ' 1 orden ascendente
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INDICE_COLUMNA_ELEMENTO = 5 ' definimos la columna por la que queremos ordenar
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ListView2.Sorted = False
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SendMessage2 ListView2.hwnd, _
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LVM_SORTITEMS, _
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ListView2.hwnd, _
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ByVal FARPROC(AddressOf CompareValues)
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' para subir el cursor arriba y ver el ultimo elmento añadido al listview
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ListView2.ListItems.Item(1).Selected = True
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'------------------------------------------------------
Para conseguir ordenar usaremos el siguiente código (llamada a sistema) Tambien sirve para ordenar Fechas:
Visual Basic:
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'--------------------------- ORDEN DEL LISTVIEW NUMERICO Y FECHAS--------------
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''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
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' Copyright ©1996-2008 VBnet, Randy Birch, All Rights Reserved.
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' Some pages may also contain other copyrights by the author.
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'controlzeta.net modificaciones
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''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
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' Distribution: You can freely use this code in your own
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' applications, but you may not reproduce
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' or publish this code on any web site,
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' online service, or distribute as source
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' on any media without express permission.
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''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
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Public objFind As LV_FINDINFO
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Public objItem As LV_ITEM
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Public INDICE_COLUMNA_ELEMENTO As Integer
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'variable to hold the sort order (ascending or descending)
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Public sOrder As Boolean
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Public Type POINTAPI
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X As Long
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Y As Long
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End Type
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Public Type LV_FINDINFO
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flags As Long
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psz As String
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lParam As Long
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pt As POINTAPI
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vkDirection As Long
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End Type
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Public Type LV_ITEM
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mask As Long
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iItem As Long
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iSubItem As Long
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state As Long
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stateMask As Long
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pszText As String
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cchTextMax As Long
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iImage As Long
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lParam As Long
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iIndent As Long
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End Type
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'Constants
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Public Const LVFI_PARAM As Long = &H1
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Public Const LVIF_TEXT As Long = &H1
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Public Const LVM_FIRST As Long = &H1000
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Const LVM_SCROLL = (LVM_FIRST + 20) ' extraña
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Public Const LVM_FINDITEM As Long = (LVM_FIRST + 13)
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Public Const LVM_GETITEMTEXT As Long = (LVM_FIRST + 45)
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Public Const LVM_SORTITEMS As Long = (LVM_FIRST + 48) 'API declarations
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Private Declare Function SendMessage3 Lib "user32" Alias "SendMessageA" (ByVal _
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hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, _
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lParam As Any) As Long
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'Declarada en InputEx le he tenido que cambiar a sendMessage2
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Public Declare Function SendMessage2 Lib "user32" _
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Alias "SendMessageA" _
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(ByVal hwnd As Long, _
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ByVal wMsg As Long, _
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ByVal wParam As Long, _
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lParam As Any) As Long
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Public Function CompareDates(ByVal lParam1 As Long, _
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ByVal lParam2 As Long, _
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ByVal hwnd As Long) As Long
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'CompareDates: This is the sorting routine that gets passed to the
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'ListView control to provide the comparison test for date values.
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'Compare returns:
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' 0 = Less Than
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' 1 = Equal
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' 2 = Greater Than
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Dim dDate1 As Date
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Dim dDate2 As Date
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'Obtain the item names and dates corresponding to the
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'input parameters
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dDate1 = ListView_GetItemDate(hwnd, lParam1)
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dDate2 = ListView_GetItemDate(hwnd, lParam2)
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'based on the Public variable sOrder set in the
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'ColumnHeader click sub, sort the dates appropriately:
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Select Case sOrder
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Case True 'sort descending
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If dDate1 <dDate2 Then
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CompareDates = 0
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ElseIf dDate1 = dDate2 Then
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CompareDates = 1
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Else
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CompareDates = 2
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End If
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Case Else 'sort ascending
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If dDate1> dDate2 Then
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CompareDates = 0
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ElseIf dDate1 = dDate2 Then
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CompareDates = 1
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Else
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CompareDates = 2
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End If
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End Select
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End Function
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Public Function CompareValues(ByVal lParam1 As Long, _
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ByVal lParam2 As Long, _
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ByVal hwnd As Long) As Long
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'CompareValues: This is the sorting routine that gets passed to the
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'ListView control to provide the comparison test for numeric values.
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'Compare returns:
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' 0 = Less Than
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' 1 = Equal
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' 2 = Greater Than
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Dim val1 As Long
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Dim val2 As Long
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'Obtain the item names and values corresponding
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'to the input parameters
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val1 = ListView_GetItemValueStr(hwnd, lParam1)
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val2 = ListView_GetItemValueStr(hwnd, lParam2)
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'based on the Public variable sOrder set in the
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'columnheader click sub, sort the values appropriately:
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Select Case sOrder
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Case True 'sort descending
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If val1 <val2 Then
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CompareValues = 0
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ElseIf val1 = val2 Then
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CompareValues = 1
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Else
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CompareValues = 2
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End If
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Case Else 'sort ascending
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If val1> val2 Then
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CompareValues = 0
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ElseIf val1 = val2 Then
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CompareValues = 1
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Else
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CompareValues = 2
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End If
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End Select
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End Function
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Public Function ListView_GetItemDate(hwnd As Long, lParam As Long) As Date
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Dim hIndex As Long
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Dim r As Long
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'Convert the input parameter to an index in the list view
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objFind.flags = LVFI_PARAM
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objFind.lParam = lParam
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hIndex = SendMessage(hwnd, LVM_FINDITEM, -1, objFind)
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'Obtain the value of the specified list view item.
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'The objItem.iSubItem member is set to the index
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'of the column that is being retrieved.
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objItem.mask = LVIF_TEXT
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objItem.iSubItem = INDICE_COLUMNA_ELEMENTO
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objItem.pszText = Space$(32)
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objItem.cchTextMax = Len(objItem.pszText)
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'get the string at subitem 1
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'and convert it into a date and exit
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r = SendMessage(hwnd, LVM_GETITEMTEXT, hIndex, objItem)
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If r> 0 Then
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ListView_GetItemDate = CDate(Left$(objItem.pszText, r))
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End If
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End Function
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Public Function ListView_GetItemValueStr(hwnd As Long, lParam As Long) As Long
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Dim hIndex As Long
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Dim r As Long
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'Convert the input parameter to an index in the list view
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objFind.flags = LVFI_PARAM
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objFind.lParam = lParam
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hIndex = SendMessage(hwnd, LVM_FINDITEM, -1, objFind)
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'Obtain the value of the specified list view item.
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'The objItem.iSubItem member is set to the index
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'of the column that is being retrieved.
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objItem.mask = LVIF_TEXT
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objItem.iSubItem = INDICE_COLUMNA_ELEMENTO
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objItem.pszText = Space$(32)
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objItem.cchTextMax = Len(objItem.pszText)
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'get the string at subitem
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'and convert it into a long
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r = SendMessage(hwnd, LVM_GETITEMTEXT, hIndex, objItem)
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If r> 0 Then
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ListView_GetItemValueStr = CLng(Left$(objItem.pszText, r))
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End If
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End Function
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Public Function FARPROC(ByVal pfn As Long) As Long
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'A procedure that receives and returns
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'the value of the AddressOf operator.
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'This workaround is needed as you can't assign
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'AddressOf directly to an API when you are also
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'passing the value ByVal in the statement
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'(as is being done with SendMessage)
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FARPROC = pfn
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End Function
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' ------------------------------- FIN CODIGO ORDEN LISTVIEW --------------------