not-working .Contains in ListViewSubItem

[Suriv]

OK, I have a strange problem with a ListView control.
The control has the property .View = Details, with 7 columns.

I want to determine whether or not a SubItem of an Item in a ListView exist or not with the following code:

Dim item As New ListViewItem
item.Text = strBlablabla

Dim subItem As New ListViewItem.ListViewSubItem(item, "blablablaSubItem")

If the SubItem really exists in the ListView, item.SubItems.Contains(subItem) should return True, right?
But it doesn't... why not?

Thx in advance

 

[cjard]

Please post the actual code

 

[Suriv]

Dim item As New ListViewItem
item.Text = strSplit(0)

lvwNetworks.Items.Add(item)
item.SubItems.Add(strSplit(4))
item.SubItems.Add(strSplit(2))
item.SubItems.Add(strSplit(3))
item.SubItems.Add(strSplit(5))
item.SubItems.Add(strSplit(6))
item.SubItems.Add(strSplit(7))

Dim subItem As New ListViewItem.ListViewSubItem(item, strSplit(4))

If item.SubItems.Contains(subItem) Then
    MsgBox("Contains")
Else
    MsgBox("Does not contain")
End If

 

[cjard]

What happens if you do:

If item.SubItems.Contains([B]strSplit[/B](4)) Then
    MsgBox("Contains")
Else
    MsgBox("Does not contain")
End If

 

[Suriv]

strSplit(4) is underlined with the error
Value of type 'String' cannot be converted to 'System.Windows.Forms.ListViewItem.ListViewSubItem'.

 

[cjard]

ah.. okay

Well, I guess it doesnt work because you make a new LVSubItem object that just so happens to be displaying the same string as an existing item, and then calling .Contains() which will use the default comparison.. Given that LVSubItem might never override .Equals() it will probably be using Object's .Equals() implementation, which is simply to compare the memory addresses. As you have 2 different objects, their memory addresses will be different.

Can I ask what youre using a listview for? Is it for tabular/grid representation of data? Would you think a grid would be better?

 

[Suriv]

It is like you said for representing tabular data.

A grid? You mean a DataGridView?

 

[cjard]

Thats pretty much what I had in mind..

 

[Suriv]

If think i've solved the problem without using a DataGridView:

if lvwNetworks.Items.Item(0).SubItems(1).Text = strSplit(4) then
msgbox("Contains")
else
msgbox("Does not contain")
end if

Thx anyway

 

[rfaricy]

Like many other collections, I believe .Contains() in context of a ListViewSubItemCollection uses the .SubItem.Name property to search; it does not look for the .SubItem.Text property. When you create your subitem, name it with a primary key and you will have better luck.