I'm working on a small class that grabs TV listings (extensive parsing) from the web and enters it into a usable format. However, when I try to access the information stored in an array in this class, I receive a System.NullReferenceException error (i.e. Object reference not set to an instance of an object). I will include the code here (with some shorthand - the parsing code makes everything look muddled).
The easiest way I found was to find the URLs for the individual networks, and downloading the program information from each network separately. So this is after all the URLs are found for the networks.
So, this seems to work alright, but when I run this code later on:
The error occurs at the *****. This is quite confusing for me because if the object didn't exist, I would think the For Each would not continue... I must be making a mistake somewhere, but I cannot find where. Thank you in advance for any help you can render.
Sincerely,
Dale Bustad
The easiest way I found was to find the URLs for the individual networks, and downloading the program information from each network separately. So this is after all the URLs are found for the networks.
Code:
Public Structure TVProgram
Public Time As String
Public Name As String
End Structure
Public Structure TVNetwork
Public ProgramArray() As TVProgram
Public Name As String
Friend URL As String
End Structure
Public Class TVInfo
Public Shared OutputText As String
Public NetworkArray() As TVNetwork
Private intCount As Integer
Public Function GetListings() As Boolean
' ...
' This is where all the URLs are found for the networks
' and entered into the NetworkArray array. I'm not
' including it because I'm quite sure it works, and is
' ugly.
' ...
For Each i As TVNetwork In NetworkArray
strHTML = 'html of specific network programming info
Dim intLoc As Integer = 1
'Find the network name, i.e. "CBS - Channel 5"
Do
If Mid(strHTML, intLoc, 20) = "<font face=arial><b>" Then
For intTemp As Integer = intLoc To Len(strHTML)
If Mid(strHTML, inttemp, 4) = "</b>" Then
i.Name = Mid(strHTML, intLoc + 20, inttemp - intLoc - 20)
Exit Do
End If
Next intTemp
End If
intLoc = intLoc + 1
Loop While intLoc < Len(strHTML)
'Find tv program names and times
Dim intProgramArray As Integer = 0
ReDim Preserve i.ProgramArray(0)
Do
If Mid(strHTML, intLoc, 10) = "nowrap><b>" Then
'times
For intTemp As Integer = intLoc To Len(strHTML)
If Mid(strHTML, intTemp, 4) = "</b>" Then
i.ProgramArray(intProgramArray).Time = Mid(strHTML, intLoc + 10, intTemp - intLoc - 10)
Exit For
End If
Next
'names
For intTemp As Integer = intLoc To Len(strHTML)
If Mid(strHTML, intTemp, 14) = "&.intl=us""><b>" Then
For intTemp2 As Integer = intTemp To Len(strHTML)
If Mid(strHTML, intTemp2, 4) = "</b>" Then
i.ProgramArray(intProgramArray).Name = Mid(strHTML, intTemp + 14, intTemp2 - intTemp - 14)
Exit For
End If
Next
Exit For
End If
Next
ReDim Preserve i.ProgramArray(i.ProgramArray.GetLength(0))
'previous line works because redim is zero-based, while getlength is 1-based
End If
intLoc = intLoc + 1
Loop While intLoc < Len(strHTML)
Next
End Function
End ClassSo, this seems to work alright, but when I run this code later on:
Code:
Dim temp As New TVListingsInfo.TVInfo
temp.GetListings()
For Each p As TVListingsInfo.TVNetwork In temp.NetworkArray
TVListingsInfo.TVInfo.AddToText(p.Name)
TVListingsInfo.TVInfo.AddToText(p.URL)
For Each q As TVListingsInfo.TVProgram In p.ProgramArray
TVListingsInfo.TVInfo.AddToText(q.Name)
TVListingsInfo.TVInfo.AddToText(q.Time)
Next ' *****
Next
TextBox1.Text = TVListingsInfo.TVInfo.OutputTextThe error occurs at the *****. This is quite confusing for me because if the object didn't exist, I would think the For Each would not continue... I must be making a mistake somewhere, but I cannot find where. Thank you in advance for any help you can render.
Sincerely,
Dale Bustad