CODEWITHSUNDEEP
vb.net
Sanguine-Scars
Sanguine-Scars

Reputation: 13

Saving Data to a Text File in VB.Net

I've a functioning streamwriter that creates a text file and places the information I need in that file, but whenever I re-run the application the text file is created anew with the current values replacing the old. How do I ensure that previous data is saved in the text file with the new data being added on to it? Appending the data to the file seems to be the obvious route, but I'm just not sure how to incorporate the code for that into my program.

Dim CorpID, Fname, Lname, PreConf, ConfCost As String
        CorpID = txtCorpID.Text
        Fname = txtFirstName.Text
        Lname = txtLastName.Text
        If radNotAttending.Checked = True Then
            PreConf = ""
        Else
            PreConf = cmbCourses.SelectedItem.ToString
        End If
        ConfCost = decAttendCost.ToString("C")

        Dim wr As StreamWriter
        wr = New StreamWriter("C:\Users\Anon\Documents\SampleTextFile.txt")
        wr.WriteLine(String.Format("{0},{1},{2},{3}, {4}", CorpID, Fname, Lname, PreConf, ConfCost))
        wr.Flush()
        wr = Nothing

Upvotes: 0

Views: 7477

Answers (2)

Rafa Gomez
Rafa Gomez

Reputation: 710

You need another Overload of the StreamWriter Constructor.

Just use wr = New StreamWriter("C:\Users\Anon\Documents\SampleTextFile.txt", true)

You need this one

Example:

Using wr As new StreamWriter("C:\Users\Anon\Documents\SampleTextFile.txt",true)
    wr.WriteLine($"{CorpID},{Fname},{Lname},{PreConf},{ConfCost})
End Using

With using, StreamWriter is released when done with it, so when you click the button again, no StreamWriter is accessing the file and you can create another insatnce of StreamWriterwithout problems.

Upvotes: 1

David
David

Reputation: 219077

There's an overload of the StreamWriter constructor for exactly this purpose:

wr = New StreamWriter("C:\Users\Anon\Documents\SampleTextFile.txt", True)

The second parameter is:

true to append data to the file; false to overwrite the file. If the specified file does not exist, this parameter has no effect, and the constructor creates a new file.

Upvotes: 0

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