Listview refresh

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durilai

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Joined
Oct 20, 2005
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I have a simple form that has a listview that is populated by a table in access. There is a button that opens another form using showdialog so that the first form stays in the background. The second form is used to add a value to that same access table. When I click the add button I want the value to be added, the current form to close and the new value to show in the listview. Everything works except the new value does not show, if I stop and then start the project the value appears. So I just need to refresh the listview which is being populated on formload. I have tried to use the refresh and update command, but to no avail. Any help is greatly appreciated.

Thanks
 
You have to repopulate the listview...or just add the new item to the end (if it's not sorted or you don't care)

Put the code you use to populate it in a seperate function and call it when it needs to be refreshed, but add

listview.Items.Clear()

as the first line in the new function.

And call that function at load
 
I have tried that. The problem is that its on a second form and the listview is populated on the first form's form load, so clearing the listview does no good. I need a way to reload the form with out creating a new instance of it. Or a better method, but I am just trying to accomplish four things.

1. View an access table
2. Add a Record to an access table
3. Refresh the list
4. Pass a value to a seperate form

I am able to view, and update the table. I am now trying to refresh the list, and pass the value.

Thanks for your help.
 
The problem is that its on a second form and the listview is populated on the first form's form load, so clearing the listview does no good.
Click to expand...

The listview should be populated by it's own container.

And no matter what, if you reload the listview after a new record is added or deleted, it will show the new/deleted record!
 
This is what I have:

#Region " .... Fetch data .... "
Private Sub fetching()
Me.ListView1.Items.Clear()
Try

strSQL = "SELECT * FROM class"
cmd = New OleDbCommand(strSQL, oledbcon)
objRead = cmd.ExecuteReader
While objRead.Read
lvItem = Me.ListView1.Items.Add(objRead("ClassID") & "")
lvItem.SubItems.Add(objRead("ClassDescription") & "")
lvItem.SubItems.Add(objRead("ClassDate") & "")
End While
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try
End Sub
#End Region

#Region " .... load event .... "
Private Sub frmClass_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

End Sub
#End Region

Private Sub ListView1_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ListView1.SelectedIndexChanged
oledbcon.Open()
fetching()
oledbcon.Close()
End Sub

If I place the db open, fetch, dbclose items to the form load area then it populates the listview automatically, but as it is there nothing happens
 
You are reloading the listview on the wrong event.
If you reload the listview on the selectedindexchanged event, everytime the user selects a new row the listview will be reloaded.

If right now all you are doing is adding a record the database, you need to send an event to this form when a record is successfully added to the database.

Take a look at my other post to add the event.

Also, you might want to fix up your 'fetching' code...

Get rid of the class variables...except for oledbcon


Visual Basic: 
  Private Sub LoadClasses()
        Me.ListView1.Items.Clear()

        Dim command As OleDbCommand
        Dim reader As OleDbDataReader

        Try
            oledbcon.Open()
            command = New OleDbCommand("SELECT * FROM class", oledbcon)
            reader = command.ExecuteReader(CommandBehavior.CloseConnection)

            While reader.Read()
                Dim lvItem As New ListViewItem(reader("ClassID").ToString())
                lvItem.SubItems.Add(reader("ClassDescription"))
                lvItem.SubItems.Add(reader("ClassDate"))
                Me.ListView1.Items.Add(lvItem)
            End While
        Catch ex As OleDbException
            MessageBox.Show(ex.Message)
        End Try

        reader.Close()
    End Sub

#End Region

#Region " .... load event .... "
    Private Sub frmClass_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Me.LoadClasses()
    End Sub
#End Region

Call LoadClasses in Form_Load and get rid of the SelectedIndexChanged Event.

And Again, add an event to the form that adds records to the database, handle the event in the parent form. Have the parent form call LoadClasses to refresh the listview.
 
I replaced what you popsted and I get an error on this line

lvItem.SubItems.Add(reader("ClassDate"))

with this error

An unhandled exception of type 'System.Reflection.AmbiguousMatchException' occurred in microsoft.visualbasic.dll

Additional information: No accessible overloaded 'ListViewSubItemCollection.Add' can be called without a narrowing conversion.
 
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