CODEWITHSUNDEEP
vb.netlistview
James Stafford
James Stafford

Reputation: 1054

Reset a listviewitem which is linked to listview

I have a listview which is bound to a listviewitem as you will see below - problem is I need to clear out the database on a timer and start from scratch,

I know to clear the listview I just do 

listview.items.clear()

problem is I need to also clear the listviewitem or it is going to rebind the same information to the listview.

declared:

    Dim TempStr(7) As String
    Dim TempNode As ListViewItem

problematic statement:

            listview2.items.clear() 
            For pop As Integer = 0 To pendrun.Rows.Count - 1
            TempStr(0) = pendrun.Rows(pop)("RID")
            Select Case pendrun.Rows(pop)("Utype")
                Case 1
                    TempStr(1) = "BLS Ambulance"
                Case 2
                    TempStr(1) = "ALS Ambulance"
                Case 3
                    TempStr(1) = "SCT Ambulance"
                Case 4
                    TempStr(1) = "Wheelchair Van"
                Case 5
                    TempStr(1) = "Taxi"
            End Select

            Select Case pendrun.Rows(pop)("Curgency")
                Case 1
                    TempStr(2) = "Scheduled"
                Case 2
                    TempStr(2) = "Non-Scheduled"
                Case 3
                    TempStr(2) = "ASAP"
                Case 4
                    TempStr(2) = "STAT"
            End Select
            TempStr(3) = pendrun.Rows(pop)("Pname")
            TempStr(4) = pendrun.Rows(pop)("Texttime")
            TempStr(5) = pendrun.Rows(pop)("sname") & " - " & pendrun.Rows(pop)("sfaddress") & ", " & pendrun.Rows(pop)("sfcity") & ", " & pendrun.Rows(pop)("sfstate")
            TempStr(6) = pendrun.Rows(pop)("dname") & " - " & pendrun.Rows(pop)("dfaddress") & ", " & pendrun.Rows(pop)("dfcity") & ", " & pendrun.Rows(pop)("dfstate")
            TempNode = New ListViewItem(TempStr)
            ListView2.Items.Add(TempNode)
            next

How do I flush all data from tempnode?

I did find

TempNode.SubItems.clear()

but this does not appear to work

Upvotes: 0

Views: 305

Answers (1)

Ňɏssa Pøngjǣrdenlarp
Ňɏssa Pøngjǣrdenlarp

Reputation: 38905

your code does not show where, when or how you try to remove the subitems. Based on the Title, I'm guessing that the LVI is already assigned to the ListView, so doing stuff to TempNode might not do anything (it could be a different LVI by this time.)

ListViewItem.SubItems.Clear() is the correct syntax but this will also remove the Item.Label So:

 ' preserve "Label" and put it back:
 Dim txt As String = LV.SelectedItems(0).Text
 LV.SelectedItems(0).SubItems.Clear()
 LV.SelectedItems(0).Text = txt

or reference as LV.Items(IndexOfTheItemToClear).Text

another way:

    ' loop BACKWARDS to remove all but the last subitem (index = 0)
    For n As Integer = LV.SelectedItems(0).SubItems.Count - 1 To 1 Step -1

        LV.SelectedItems(0).SubItems.RemoveAt(n)

    Next

since you are removing things from the collection you are looping on, you have to loop backwards otherwise your code runs out of items before N is reached.

EDIT

Your question is not nearly as clear as you might think it is. If you are trying to remove the Item represented by TempNode in the code, you have to find it and remove it. Once TempNode has been added to the LV, you cannot recreate TempNode (TempNode = New ListViewItem(TempStr)) because NEW makes a new ListViewItem which is not the same as the one you added earlier. So, you need to find the old one and remove it (not the same as clear[ing] the entire listview or flush all data from tempnode. So:

' presumably 'pendrun.Rows(pop)("RID")' is the item text, so find it:
Dim search As String = pendrun.Rows(pop)("RID")

For n as integer = 0 to LV.Items.Count - 1
    if LV.Items(n).Text = search then
        LV.Items.RemoveAt(n)
        Exit For
    End iF
Next n

It wont clear the LV but will find a specific item and remove it and the associated ListViewItem.SubItems from the LV. Matching on Text is pretty weak, so if you have something more unique like an ID, you can store that as a subitem and search that way:

 if LV.Items(n).SubItems(WhereYouPutIt).Text = search then...

or even stash it in the ListViewItem.Tag property:

if LV.Items(n).Tag = search then...

Upvotes: 1

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