How to fix 'Index was outside of bounds of the array' - arrays

Question

Using visual basic. Trying to load a series of reports onto a listview, listview consists of 3 columns (location, date and severity level) everytime it loads it crashes due to 'index being outside the bounds of the array'.Specifically around DOI = reportdetails(1) in my code. It is loading off of a textfile. I have the data within the textfile so I am unsure of why it is saying I am asking for information that doesnt exist. The program also encypts the textfile.
Dim locate, DOI, SeverityLevel, ReportTitles, EReportTitles, ReportDetails(2) As String
Dim Index As Integer 'Define Variables
Dim FileNum As Integer = FreeFile()
Dim IncidentReport As ListViewItem
lstReports.Items.Clear()
If Dir("ReportTitles.txt") <> "" Then 'If the directory of the file exits then continue
FileOpen(FileNum, "ReportTitles.txt", OpenMode.Input) 'open file
Do Until EOF(FileNum) 'Repeat until the end of the file is reached
EReportTitles = "" 'Clear variables, to safeguard against crashes or errors
ReportTitles = ""
EReportTitles = LineInput(FileNum) 'EReportTitles is equal to the current file line
Dim FileName As String = "ReportTitles.txt" 'Define variables
Dim I, C As Integer
Dim Last As Integer = EReportTitles.Length - 1
Dim ThisChar As Char
For I = 0 To Last 'Begin for loop
ThisChar = EReportTitles.Chars(I) 'Decryption of file
C = Asc(ThisChar) Xor 22
ThisChar = Chr(C)
ReportTitles += ThisChar
Next
If ReportTitles <> "" Then
ReportDetails = Split(ReportTitles, ",") 'Split the lines when a "," is encountered
locate = ReportDetails(0) 'Assosciate to relevant value in array
DOI = ReportDetails(1)
SeverityLevel = ReportDetails(2)
IncidentReport = New ListViewItem
IncidentReport.Text = locate 'Add relevant values to IncidentReport ListViewItem variable
IncidentReport.SubItems.Add(DOI)
IncidentReport.SubItems.Add(SeverityLevel)
lstReports.Items.Add(IncidentReport) 'Transfer IncidentReport to listview
Else
End If
Loop
FileClose(FileNum) 'close file
End If
Expected result is to load all of the report location, dates and severity levels onto the listview.
Also sorry about the formatting of this question, i'm new to stack overflow.

Answer 1

There's no point declaring ReportDetails like this:
ReportDetails(2) As String
because that creates an array that you never use. Here:
ReportDetails = Split(ReportTitles, ",")
you are creating a new array anyway and the length of that array will be determined by the number of delimiters in ReportTitles. If you're being told that 1 is an invalid index for that array then that array must only contain 1 element, which means that ReportTitles didn't contain any delimiters.
This is not something that we should have to explain to you because you can easily see it for yourself by debugging and you should ALWAYS debug BEFORE posting here. Set a breakpoint at the top of the code, step through it line by line and examine the state at each step. You can easily see the contents of ReportTitles and ReportDetails and anything else to see whether they are what you expect them to be.
If the point here is to read a CSV file then you really ought to be using the TextFieldParser class. The documentation for that class includes a code example.

Answer 2

This requires .Net Standard 2.1, and so I'm not sure if VB.Net can use the required SpanAction for the String.Create() method, but if it is supported it should greatly outperform the original.
lstReports.Items.Clear()
'Read and "Decrypt" (and I use that term loosely) the file with only a single heap allocation
Dim file As String
Using fs As FileStream = File.OpenRead("ReportTitles.txt")
file = String.Create(fs.Length, fs,
Sub(chars, stream)
For i As Integer = 0 To stream.Length - 1
'THIS IS NOT ENCRYPTION! At best, it's obfuscation.
chars(i) = Chr(fs.ReadByte() Xor 22)
Next
End Sub)
End Using
'Use an actual CSV parser
Using reader As New StringReader(file), _
parser As New TextFieldParser(reader)
parser.TextFieldType = FileIO.FieldType.Delimited
parser.Delimiters = New String() {","}
Dim row As String()
While Not parser.EndOfData
row = parser.ReadFields()
If row.Length >= 3 Then
Dim IncidentReport As New ListViewItem()
IncidentReport.Text = row(0) '
IncidentReport.SubItems.Add(row(1))
IncidentReport.SubItems.Add(row(2))
lstReports.Items.Add(IncidentReport)
End If
End While
End Using
If you are not able to use that version, this is not quite as good, but still a better approach than the original:
lstReports.Items.Clear()
'Load and "Decrypt" the file
Dim file As String
Using fs As FileStream = File.OpenRead("ReportTitles.txt")
Dim builder As New StringBuilder(fs.Length)
For i As Integer = 0 To fs.Length - 1
'THIS IS NOT ENCRYPTION! At best, it's obfuscation.
builder.Append(Chr(fs.ReadByte() Xor 22))
Next
file = builder.ToString()
End Using
'Use an actual CSV parser
Using reader As New StringReader(file), _
parser As New TextFieldParser(reader)
parser.TextFieldType = FileIO.FieldType.Delimited
parser.Delimiters = New String() {","}
Dim row As String()
While Not parser.EndOfData
row = parser.ReadFields()
If row.Length >= 3 Then
Dim IncidentReport As New ListViewItem()
IncidentReport.Text = row(0) '
IncidentReport.SubItems.Add(row(1))
IncidentReport.SubItems.Add(row(2))
lstReports.Items.Add(IncidentReport)
End If
End While
End Using
In both cases, use Try/Catch rather than Dir() to check whether the location exists. Just try to open the file. Dir() costs an extra disk seek, and there are precious few things in programming slower than disk I/O.