How to search for records in a text file?

I create a dataset of all the records...then apply a filter to the dataset by mapping a DATAVIEW to the dataset and then performing a filter on the DATAVIEW and then assigning the DATAVIEW to the Listbox....so basically

dsTotalList -----> Populate dataset based on sql query without filters (select * from tblBlah)

dim dvList as dataview

dvList.table = dsTotalList.Tables("tblBlah")

dvList.RowFilter = [varLongSupplierName] Like '" & txtUserFilter.Text & "'"

Map the view onto your Listbox.....

You can keep filtering and re-filtering the view every time the user hits the Command button...just change the RowFilter, then remap to the listbox...

I use this for filtering datagrids down as the user types in information...allowing them to use % for wild card since the RowFilter is similar to a SQL Where statement.

Well I think there's not much difference in approach to the problem in VB.NET
This is how you can achieve it.

        Dim TextLine As String
        Dim SearchText As String = "John"
        FileOpen(1, "C:\Test.Txt", OpenMode.Input)
        While Not EOF(1)
            TextLine = LineInput(1)
            If TextLine.IndexOf(SearchText) > -1 Then
                MsgBox(TextLine)
            End If
        End While
        FileClose(1)

However if the user searches more often you can improve upon the performance by storing individual lines in an array once and then searching everytime on that array

Arif eqbal,
I tried using your code above and nothing seems to work. Here is my code that I use iin the VB 5.0 application:

Dim PhoneFile As Long
PhoneFile = FreeFile
Dim str As String
Dim strng2 As String
Dim x As Integer

Open "C:\Phonelist.txt" For Input Access Read As PhoneFile

Do Until EOF(PhoneFile)
Screen.MousePointer = vbHourglass
    Line Input #PhoneFile, str
    strng2 = Mid$(str, 8, 80)
    x = InStr(1, strng2, txtSearchString, vbTextCompare)
    If x > 0 Then
        lstResults.AddItem strng2
    End If
Loop

Close #PhoneFile