Listview: Item always visible
Whenever you add new items to a listview control ListViewItems, and these are so numerous that the control does not have enough space to display them on screen, adding a vertical scroll bar. This is perfect, except that by default are not that new items are added.
Today I want to show how to solve this little problem.
Visual basic controls. The cone net listview give us an impressive array of properties for configuration, so that often are unknown.
I want to show a simple example. For that we need a form, a listview control and a button.
The properties that most interest us are:
- HideSelection: Setting this to false if no listview control has the focus, we continue to see what the selected item.
- ListView1.FocusedItem.EnsureVisible () to force the selected item to be always visible.
Well, now if the code:
Private Sub Form1_Load (ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
ListView1.HideSelection = False
ListView1.FullRowSelect = True
ListView1.MultiSelect = False
End Sub
Private Sub Button1_Click (ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Static i As Integer = 0
i + = 1
ListView1.Items.Add (New ListViewItem ("Item number" & i))
ListView1.Items (ListView1.Items.Count - 1). Selected = True
ListView1.Items (ListView1.Items.Count - 1). Focused = True
ListView1.FocusedItem.EnsureVisible ()
End Sub
Running it should look much like what is shown in this image:
That's all, if this information helped you, please leave a comment.
11 Responses to "Listview: Item always on top"
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Rate in Bitacoras.com: Whenever you add new items to a listview control ListViewItems, and these are so numerous that the control does not have enough space to display them on screen, adding a vertical scroll bar. This is .....
Well we all know q to display the data but I q I'm interested if they can explain how are stored in a module are sawing the program aunq
A QUESTION I WANT THAT SAME BUT FOR EXAMPLE DataGridView IF NOT COULD HELP ME IN THIS ISSUE
MY EMAIL:
richardramos789@hotmail.com
YOU WOULD BE GRATEFUL IF you help me
Hello such,
Look I have a doubt with a listview to implement on my system, I'm putting together a POS system and enter a code in my txtbox achievement in my listview print correctly, my question is that I want when registering the same product, rather than adding a new row is added to it and in the Quantity column will increase the number.
For example if I add 12345, is printed in my listview, but if I add 12345 to place print on a new row is printed in a row but in column amount increases to 2, not if I explain or could guide me in this question that I have I would greatly appreciate.
I have no very clear what you want to do, but I suggest that you look at this example may be helpful: http://www.solovb.net/index.php/2009/02/19/modificar-datos- of-a-listview /
Any further questions do not hesitate to contact me.
Regards
Hello George, what you ask involves data persistence and to update a column belonging to the rank of a specific key in a table by 2 solutions you can choose: first you create a DB with the fields you need and use a connection either with MySQL using the adapter for it or the SQL Server is included with Visual Studio, the other way is through flat files that save the data in a file. txt and then proceed to the reading and rewriting of some data , for both options as you need to increase the value for a column rewquerida, you should also apply a function to increase this value based on the condition you require.
Elisha thank you very much for your prompt response.
Ok look I'll explain. I have a TextBox in which add the products I have in my DB, ok for example, Coca-cola, I enter the bar code on my TextBox in this case would be 12345678, good showing in my listview the product description with my columns listview are:
Product Code, Description, Quantity, Sale Price, Existence.
Then add the product to my row is full of such data in my listview, but if I re-insert the code of coca-cola, is shown in a next row, which I like to do is that when you insert another Once the product itself rather than in a new row, just change the number of my column Quantity, in this case exchange to 2.
That's more than nd I want to do, if I could say more or less answer this question I'd appreciate it.
Thanks
Well, now is a little lighter.
The first thing you do before inserting a new line is to cross the listview to check if you have already entered the code you are trying to insert.
That you do a For Each, for example
"I think a variable to indicate whether I found the code already existed
Dim exists As Boolean = False
For each item as ListViewItem in listviewProductos.items
Then if item.text = txtCodigo.text
'If you come here is because it was already loaded
cantidadAnterior dim as Integer = CType (item.subitm (2). text, Integer)
item.subitem (2). cantidadAnterior + text = CType (txtCantidad.text, Integer)
'If you find you notice that already existed
exists = True
end if
Next
If Not Then there
'Here it is not found then insert
End if
Well, Espro serve ... you can not rule out a typo Terner since I wrote it directly here
But surely you will serve
Thanks again,
See you commented that if I had worked on that issue by changing the value of the Quantity column, what happens is I'm extracting values from a MySQL database I show looks like the code print my listview
Listview Private Sub ()
Dim i As Integer
Dim s As Integer
Dim count As Integer
Subtotal Dim As Double
Dim list As New ListViewItem
As New MySqlCommand Dim string ("SELECT * FROM products WHERE ProductCode = '" & txtCodigoBarras.Text & "'", con)
cadena.ExecuteReader mysqldr = ()
While mysqldr.Read ()
list = listView1.Items.Add (txtCodigoBarras.Text.Trim)
listar.SubItems.Add (CStr (mysqldr ("Description")))
listar.SubItems.Add (CStr (mysqldr ("Quantity")))
listar.SubItems.Add (CStr (mysqldr ("PrecioVenta")))
listar.SubItems.Add (CStr (mysqldr ("Stock")))
End While
Dim exists As Boolean = False
For Each item As ListViewItem In ListView1.Items
Then if item.Text = txtCodigoBarras.Text
CantidadAnterior Dim As Integer = CType (listar.SubItems (2). Text, Integer)
listar.SubItems (2). Text = cantidadAnterior + CType (mysqldr ("Quantity"), Integer)
exists = True
End If
Next
If Not Then there
End If
lblCantidadProd.Text = mysqldr.Item (3)
lblPrecioUnidad.Text = mysqldr.Item (5)
For s = 0.0 To ListView1.Items.Count - 1
Subtotal = Subtotal + ListView1.Items (s). SubItems (3). Text
Next
lbLSubTotal.Text = "$" & Format (Subtotal, "0.00")
For i = 0 To ListView1.Items.Count - 1
counter = counter + ListView1.Items (i). SubItems (2). Text
Next
Me.lblContador.Text = counter
mysqldr.Close ()
End Sub
The code that I spent so implement it and see the results in the following photo:
http://img193.imageshack.us/img193/4421/productosv.jpg
Friend haha sorry if I upset with so many questions, but I'm finding more or less the problem, for example introduce the product
DORITOSNAC
Is inserted in the front row and when I put DORITOSNAC is printed on the second row but had already introduced the first changes its value from quantity to 2 and is printed back to enter again on a 3 row but equally the from 1 row changes its value to 3
Then if txtCodigoBarras.Text = txtCodigoBarras.Text
Dim exists As Boolean = False
For Each item As ListViewItem In ListView1.Items
Then if item.Text = txtCodigoBarras.Text
CantidadAnterior Dim As Integer = CType (item.SubItems (2). Text, Integer)
item.SubItems (2). Text = cantidadAnterior + CType (lblCantidadProd.Text, Integer)
exists = True
End If
Next
If Not Then there
End If
Let's see if I get it now if not any explanation on your part will be grateful.
already achieved solve many thanks for your support get the solution:
Dim count As Integer
For j As Integer = 0 To Me.ListView1.Items.Count - 1
If Me.ListView1.Items (j). SubItems (0). Then Text = txtCodigoBarras.Text
count = CInt (Me.ListView1.Items (j). SubItems (2). Text) + 1
Me.ListView1.Items (j). SubItems (2). Text = count
Exit Sub