VB.net program to grab lines from files that contain a certain text pattern

Brian
Brian used Ask the Experts™
I have the following code that iterates thru files ending in .dat within a folder. Now what I want to do is go into each file and grab one line at a time, and if that line contains "PO-", then I want to put it into an array. I'm thinking I need another loop (maybe another Next loop?). Can someone help me to grab lines containing "PO-" within these files and put them into an array? Thanks!
    Private Sub btnSaveReport_Click(sender As Object, e As EventArgs) Handles btnSaveReport.Click
        Try
            Dim arrayPOentries() As String
            Dim strSourceFileLocation As String = AppDomain.CurrentDomain.BaseDirectory + "_data/"
            Dim strDetinationFileLocation As String = tbSaveFileLocation.Text
            Dim Paths() As String = IO.Directory.GetFiles(strSourceFileLocation, "*.dat")
            For Each Path As String In Paths
                'another loop here?
            Next
        Catch ex As Exception
            MessageBox.Show(ex.Message)
        End Try
        Me.Close()
    End Sub

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Commented:
Brian

Rather than an array it might be better to use a List, if you really need an array the list can be converted later.
Private Sub btnSaveReport_Click(sender As Object, e As EventArgs) Handles btnSaveReport.Click

Dim arrayPOentries() As String
Dim strSourceFileLocation As String = AppDomain.CurrentDomain.BaseDirectory + "_data/"
Dim strDetinationFileLocation As String = tbSaveFileLocation.Text
Dim Paths() As String = IO.Directory.GetFiles(strSourceFileLocation, "*.dat")
Dim Results As New List(Of String)()

    Try
			
        For Each Path As String In Paths
			
            For Each line As String In File.ReadAllLines(Path)
                If line.Contains("PO-") Then
                    Results.Add(line)
                End If
            Next line

        Next Path

    Catch ex As Exception
        MessageBox.Show(ex.Message)
    End Try

    Me.Close()

End Sub

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BrianSystems Administrator

Author

Commented:
Oh thank you so much, this is awesome! I was trying this Do loop and getting an "object reference not set to an instance of an object" error. Your code is much cleaner.
	Private Sub btnSaveReport_Click(sender As Object, e As EventArgs) Handles btnSaveReport.Click
        Try
            Dim strSourceFileLocation As String = AppDomain.CurrentDomain.BaseDirectory + "_data/"
            Dim strDetinationFileLocation As String = tbSaveFileLocation.Text
            Dim Paths() As String = IO.Directory.GetFiles(strSourceFileLocation, "*.dat")
            For Each Path As String In Paths
                Dim reader As StreamReader = My.Computer.FileSystem.OpenTextFileReader(Path)
                Dim strLine As String
                Do
                    strLine = reader.ReadLine
                    If strLine.Contains("PO-") Then
                        MsgBox(strLine)
                    End If
                Loop Until strLine Is Nothing
                reader.Close()

            Next
        Catch ex As Exception
            MessageBox.Show(ex.Message)
        End Try
        Me.Close()
    End Sub

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BrianSystems Administrator

Author

Commented:
Thank you so much for your help! Awesome code... very concise!

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