I am trying to extract some links from a webpage. Here is my code, but for some reason it's not getting the text.
I am trying to capture all the news that has the finance word, and adding the string back when I navigate to it.
I am getting error (Object reference not set to an instance of an object) at line ( iPos = strSource.IndexOf(strStart, startPos))
Code:
dim survpage As String
Dim webclient As New Net.WebClient
Dim survpage As String = webclient.DownloadString("http://www.yahoo.com/")
End Sub
Private Sub Button2_Click(sender As System.Object, e As System.EventArgs) Handles Button2.Click
For Each line As String In GBA(survpage, "finance.yahoo.com/blogs/", "html")
ListBox1.Items.Add(line)
Next
End Sub
Public Function GBA(ByRef strSource As String, ByRef strStart As String, ByRef strEnd As String, _
Optional ByRef startPos As Integer = 0) As List(Of String)
Dim iPos As Integer, iEnd As Integer, strResult As String, lenStart As Integer = strStart.Length
Dim L As New List(Of String)
Do Until iPos = -1
strResult = String.Empty
iPos = strSource.IndexOf(strStart, startPos)
iEnd = strSource.IndexOf(strEnd, iPos + lenStart)
If iPos <> -1 AndAlso iEnd <> -1 Then
strResult = strSource.Substring(iPos + lenStart, iEnd - (iPos + lenStart))
L.Add(strResult)
startPos = iPos + lenStart
End If
Loop
Return L
End FunctionI am getting error (Object reference not set to an instance of an object) at line ( iPos = strSource.IndexOf(strStart, startPos))