when I enter TEXT in sub-serial, MUST BE CHECK FIRST IF THE TEXT IS ALREADY IN LISTBOX.ITEMS

how do I check the listbox.item = subserial.text?

CodePudding user response：

You can use FindStringExact

bool contains = listbox.FindStringExact(subserial.Text) != -1;

CodePudding user response：

For Each a As String In String.Join(vbCrLf, ListBox1.Items.Cast(Of String))
        If txtSS.Text = a Then
            MsgBox("It's already barcoded!")
            txtSS.Text = ""
        End If
    Next

I GOT IT!