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Help with selecting multiplr rows from listbox control using VB.NET

Posted on 2014-01-02
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Last Modified: 2014-02-01
Hi,

I loaded my listbox control from an xml file, when i use the code below to select mutiple rows, I receive the following error:

Operator '+' is not defined for string "," and type 'DataRowView'.


On line:

tempstring += "," + item

The error does not occur if I add the countries in the items collection of the listbox control, but I need to load the control from the xml file.


How di i fix this problem?


 Private Sub ListBox1_Click(sender As Object, e As System.EventArgs) Handles ListBox1.Click
        tempstring = ""

        For Each item As Object In Me.ListBox1.SelectedItems

            tempstring += "," + item

        Next

        If tempstring <> "" Then



            tempstring = Microsoft.VisualBasic.Right(tempstring, Len(tempstring) - 1)


        End If

        Me.C1TrueDBGrid45.Columns("Receiver").Text = tempstring
            End Sub


Code to load listbox from Form load event.

  fsReceiver1 = New System.IO.FileStream(Application.StartupPath + "\Receiver.xml", IO.FileMode.Open)
        dtsetReceiver.Clear()
        dtsetReceiver.ReadXml(fsReceiver1)
        fsReceiver1.Close()
        Me.ListBox1.DataSource = dtsetReceiver.Tables(0)
        Me.ListBox1.DisplayMember = "Receiver"

Thanks,

Victor
0
Comment
Question by:vcharles
  • 2
4 Comments
 
LVL 12

Expert Comment

by:ktaczala
ID: 39753211
Try tempstring = tempstring & "," & item, instead of  tempstring += "," + item
0
 
LVL 52

Expert Comment

by:Carl Tawn
ID: 39753434
I'm guessing you've bound your listbox to something that is returning a DataTable. When you are trying to append, you are trying to append a DataRowView object, rather than the text within the field being displayed.

You probably need something more like:
tempstring &= "," & item.Item("NameOfColumn").ToString()

Open in new window

0
 

Author Comment

by:vcharles
ID: 39755305
Hi,

Unfortunately both approaches did not work, when I tried the first solution I received the following error:
Operator '&' is not defined for string "," and type 'DataRowView'.

When I tried the last approach(tempstring &= "," & item.Item("Receiver").ToString()
) in the code below, for some reason, all the rows in the Grid dissapear when I select a row from the listbox. Any ideas why the rows in the Grid dissapears?

Private Sub ListBox1_Click(sender As Object, e As System.EventArgs) Handles ListBox1.Click
        tempstring = ""

        For Each item As Object In Me.ListBox1.SelectedItems
                      tempstring &= "," & item.Item("Receiver").ToString()
              Next
        If tempstring <> "" Then
            tempstring = Microsoft.VisualBasic.Right(tempstring, Len(tempstring) - 1)
        End If
        Me.C1TrueDBGrid45.Columns("Receiver").Text = tempstring
            End Sub

Thanks.

V.
0
 
LVL 52

Accepted Solution

by:
Carl Tawn earned 500 total points
ID: 39755850
Probably because this line:
Me.C1TrueDBGrid45.Columns("Receiver").Text = tempstring

Open in new window

Is setting the value for the entire column, not just for the current row.
0

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