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Visual Basic - How to determined the index of a item in ListView

    Question

  • I have determined the item in a listview that I with to remove (by searching by way of my code).  Now I would like to determined the index of that item so I can use removeat(index) to remove the item.  How do I determined the index? or can I remove that item without knowing the index?  Please help.

    Ed.


    ecb

    Monday, December 31, 2012 12:09 AM

Answers

  • Public Class Form1
    
        Dim LViewToDelete As Integer = 10000000
    
        Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    
            ListView1.AllowColumnReorder = True
            ListView1.GridLines = True
            ListView1.View = View.Details
            ListView1.Sorting = SortOrder.Ascending
    
            ListView1.Columns.Add("Instance", 200, HorizontalAlignment.Left)
            ListView1.Columns.Add("Instance Nr 1", 200, HorizontalAlignment.Left)
            ListView1.Columns.Add("Instance Nr 2", 200, HorizontalAlignment.Left)
            ListView1.Columns.Add("Instance Nr 3", 200, HorizontalAlignment.Left)
    
            Dim item1 As New ListViewItem("1st instance")
            item1.SubItems.Add("1st instance 1")
            item1.SubItems.Add("1st instance 2")
            item1.SubItems.Add("1st instance 3")
            ListView1.Items.AddRange(New ListViewItem() {item1})
    
            Dim item2 As New ListViewItem("2nd instance")
            item2.SubItems.Add("2nd instance 1")
            item2.SubItems.Add("2nd instance 2")
            item2.SubItems.Add("2nd instance 3")
            ListView1.Items.AddRange(New ListViewItem() {item2})
    
            Timer1.Interval = 2000
            Timer1.Start()
    
        End Sub
    
        Private Sub ListView1_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ListView1.SelectedIndexChanged
    
        End Sub
    
        Private Sub Button2_Click(sender As Object, e As EventArgs)
            ListView1.FindItemWithText(TextBox1.Text).Index.ToString()
        End Sub
    
        Private Sub TextBox1_TextChanged(sender As Object, e As EventArgs) Handles TextBox1.TextChanged
            
        End Sub
    
        Private Sub TextBox1_KeyDown(sender As Object, e As KeyEventArgs) Handles TextBox1.KeyDown
    
            If e.KeyCode = Keys.Enter Then
                Try
                    LViewToDelete = CInt(ListView1.FindItemWithText(TextBox1.Text).Index.ToString())
                Catch ex As Exception
                End Try
                If LViewToDelete <> 10000000 Then
                    Try
                        ListView1.Items.RemoveAt(LViewToDelete)
                    Catch ey As Exception
                    End Try
                End If
            End If
            LViewToDelete = 10000000
    
        End Sub
    
    End Class


    You've taught me everything I know but not everything you know.

    Monday, December 31, 2012 6:14 AM
  • Ed,

    That is probably no true code, from1?????????????????????????????????

    However, I've written this in this forum endless times, people want for some reason use a listview like a DataGridView, that goes wrong as soon as you start doing the things you want to do.


    Success
    Cor

    Monday, December 31, 2012 9:01 AM
  • you can try just few lines:

            Dim ListItem As ListViewItem = listView1.FindItemWithText("test")
    
            Dim index As Integer = ListItem.Index
    
            listView1.Items.RemoveAt(index)
    ' ------------OR------------
            listView1.Items.Remove(ListItem)

    thanks


    Hirendra Sisodiya from authorcode.com

    Monday, December 31, 2012 9:09 AM

All replies

  • Ed,

    Have a look at something I posted yesterday morning here:

    http://social.msdn.microsoft.com/Forums/en-US/vbgeneral/thread/567c01b3-496c-4a44-9414-989461025beb/#858310bc-caad-4081-a977-73bc24b9eb2b

    It's the last reply if that doesn't open correctly. In it, you'll see that I have a ListView and the user has clicked the "Remove" button and I remove that item based not on the index, but on the item they've chosen (i.e., the one in the collection of the SelectedItems).


    Please call me Frank :)

    Monday, December 31, 2012 12:19 AM
  • Let me try that again - that's why I shouldn't "edit code on the fly" here:

    Private Sub btn_RemoveFile_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) _ Handles btn_RemoveFile.Click ' If ListView1.SelectedItems.Count > 0 Then ListView1.BeginUpdate() ' For i As Integer = ListView1.Items.Count - 1 To 0 Step -1 If ListView1.Items(i).Selected Then Dim lvi As ListViewItem = ListView1.Items(i) ListView1.Items.Remove(lvi) End If Next ' ListView1.EndUpdate() End If ' End Sub


    Do you see why I have to go through the list in reverse order?

    Please call me Frank :)

    Monday, December 31, 2012 12:41 AM
  • I won't be online tonight much longer, so let me answer my own question:

    When you tell it to start at the top and look to the bottom (i.e., For i As Integer = 0 To ListView1.Items.Count - 1), then you can't change anything that will alter that bottom-most index number. If you think about it, that just makes sense. Let's say I had ten items (index 0 through 9) and I remove one. Now there IS not item at index 9, right?

    That's why it will throw an exception.

    On the other hand, if you tell it to start at the bottom and look to the top, it doesn't look behind it - it's looking to the top (index 0) which you didn't change. That's why that second method works.

    Another way would be to create a temporary collection (ergo, a list of ListViewItems) and then remove them. You're not in the collection of ListView items when you do that so no harm. And to throw in yet another way, you could also create a temporary List(Of Integer) and go through the list like I showed and, if the item is selected, add that index number to the List(Of Integer).

    Now go through that list and use .RemoveAt(i) ... that would work also.

    I'll look back in here in the morning but I hope this has helped some.


    Please call me Frank :)

    Monday, December 31, 2012 1:15 AM
  • OK, Maybe I did not pose the question correctly.  I am not talking about any one clicking a button to determined the item to be remove.   My written code is searching the listview to determined what entry to remove.  Once my code has determined the item to be remove how do I get the index number of the item?  No button click.

    Ed.


    ecb

    Monday, December 31, 2012 4:52 AM
  • Maybe you could post your code so we could see how it determines what Item is to be removed and then provide you with an answer of how to find the index number.

    You've taught me everything I know but not everything you know.

    Monday, December 31, 2012 4:58 AM
  • Public Class Form1
    
        Dim LViewToDelete As Integer = 10000000
    
        Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    
            ListView1.AllowColumnReorder = True
            ListView1.GridLines = True
            ListView1.View = View.Details
            ListView1.Sorting = SortOrder.Ascending
    
            ListView1.Columns.Add("Instance", 200, HorizontalAlignment.Left)
            ListView1.Columns.Add("Instance Nr 1", 200, HorizontalAlignment.Left)
            ListView1.Columns.Add("Instance Nr 2", 200, HorizontalAlignment.Left)
            ListView1.Columns.Add("Instance Nr 3", 200, HorizontalAlignment.Left)
    
            Dim item1 As New ListViewItem("1st instance")
            item1.SubItems.Add("1st instance 1")
            item1.SubItems.Add("1st instance 2")
            item1.SubItems.Add("1st instance 3")
            ListView1.Items.AddRange(New ListViewItem() {item1})
    
            Dim item2 As New ListViewItem("2nd instance")
            item2.SubItems.Add("2nd instance 1")
            item2.SubItems.Add("2nd instance 2")
            item2.SubItems.Add("2nd instance 3")
            ListView1.Items.AddRange(New ListViewItem() {item2})
    
            Timer1.Interval = 2000
            Timer1.Start()
    
        End Sub
    
        Private Sub ListView1_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ListView1.SelectedIndexChanged
    
        End Sub
    
        Private Sub Button2_Click(sender As Object, e As EventArgs)
            ListView1.FindItemWithText(TextBox1.Text).Index.ToString()
        End Sub
    
        Private Sub TextBox1_TextChanged(sender As Object, e As EventArgs) Handles TextBox1.TextChanged
            
        End Sub
    
        Private Sub TextBox1_KeyDown(sender As Object, e As KeyEventArgs) Handles TextBox1.KeyDown
    
            If e.KeyCode = Keys.Enter Then
                Try
                    LViewToDelete = CInt(ListView1.FindItemWithText(TextBox1.Text).Index.ToString())
                Catch ex As Exception
                End Try
                If LViewToDelete <> 10000000 Then
                    Try
                        ListView1.Items.RemoveAt(LViewToDelete)
                    Catch ey As Exception
                    End Try
                End If
            End If
            LViewToDelete = 10000000
    
        End Sub
    
    End Class


    You've taught me everything I know but not everything you know.

    Monday, December 31, 2012 6:14 AM
  • Subitems is not a member of ListView1.

    You've taught me everything I know but not everything you know.

    Monday, December 31, 2012 8:52 AM
  • Ed,

    That is probably no true code, from1?????????????????????????????????

    However, I've written this in this forum endless times, people want for some reason use a listview like a DataGridView, that goes wrong as soon as you start doing the things you want to do.


    Success
    Cor

    Monday, December 31, 2012 9:01 AM
  • you can try just few lines:

            Dim ListItem As ListViewItem = listView1.FindItemWithText("test")
    
            Dim index As Integer = ListItem.Index
    
            listView1.Items.RemoveAt(index)
    ' ------------OR------------
            listView1.Items.Remove(ListItem)

    thanks


    Hirendra Sisodiya from authorcode.com

    Monday, December 31, 2012 9:09 AM
  • Monkeyboy,  this is the code that locate the item I wish to remove from the listview.  I am working with two listviews and I have already removed the item from the first listview and I wish to keep them in synch.

    For each LVI2 as listviewitem in form1.listview1.items

    If LVI.text = LVI2.text and _

       LVI.subitems(1).text = LVI2.subitems(1).text and _

       LVI.subitems(2)text  = LVI2.subitems(2).text then    '   <=== here I get my match of both items

       from1.listview1.items.removeat(XXXXXXXX)     ' <=== here is where I need the index number to remove the item

    Unless I can remove it without the index.    I am new in Visual Basic.

    Ed.


    ecb

    Ed,

    There's nothing wrong with using For Each, but if you do then you'll need to come up with your own counter. As an example:

    Dim idx As Integer = 0

    For Each lvi As ListViewItem In MyListView.Items
       'Make your comparison and if true use Exit For here
       idx += 1
    Next

    Now the integer idx is the index. Another way you could do it would be:

    Dim idx As Integer = 0

    For i As Integer = 0 To MyListView.Items.Count - 1
       ' Make your comparison and if true do the following
       idx = i
       Exit For
    Next


    Please call me Frank :)

    Monday, December 31, 2012 9:13 AM
  • Ed,

    That is probably no true code, from1?????????????????????????????????

    However, I've written this in this forum endless times, people want for some reason use a listview like a DataGridView, that goes wrong as soon as you start doing the things you want to do.

    The ListView and DataGridView serve different purposes.  Use a DataGridView for displaying data from a bound data base.  Use a ListView for unbound data.  The ListView is simpler and easier to use for unbound data.

    Monday, December 31, 2012 10:33 AM

  • The ListView and DataGridView serve different purposes.  Use a DataGridView for displaying data from a bound data base.  Use a ListView for unbound data.  The ListView is simpler and easier to use for unbound data.

    John,

    That was my idea in past also, but in fact is the DataGridView a kind of combination between the older MSFlexGrid and the DataGrid.

    Both are not completely done in the DataGridView by the way, but the DataGridView works perfectly even using the designer with unbound data.

    The listview is for me currently only good usable with all kind of files, because those can then be displayed as image, tile, list, detailed or even more inside the listview; And are as item easily to copy to the clipboard.

    If it is to show data bound or unbound the datagridview does a better job.


    Success
    Cor


    Monday, December 31, 2012 11:15 AM
  • OK, problem solved.  It work.

    Ed.


    ecb

    • Marked as answer by EdCal Monday, December 31, 2012 12:18 PM
    • Unmarked as answer by EdCal Monday, December 31, 2012 12:18 PM
    Monday, December 31, 2012 12:18 PM