如何让程序在顺序访问文件中写入新行而不是删除它？

Question

我正在尝试写入顺序访问文件，但每次单击“写入”按钮时，将从文件中删除第一个列表框选择并添加新的列表框选择，如何解决此问题？

Private Sub MainForm_Load(sender As Object, e As EventArgs) Handles Me.Load
    'fills list box with parties
    partyListBox.Items.Add("Democrat")
    partyListBox.Items.Add("Republican")
    partyListBox.Items.Add("Independent")
End Sub

Private Sub writeButton_Click(sender As Object, e As EventArgs) Handles writeButton.Click
    Dim outFile As IO.StreamWriter
    Dim party As String = partyListBox.SelectedItem.ToString
    Dim age As Integer

    Integer.TryParse(ageTextBox.Text, age)

    outFile = IO.File.CreateText("politicalparties.txt")
    'write to file
    outFile.WriteLine(party & ", " & age)
    'close file
    outFile.Close()
End Sub

Answer 1

您可以执行以下操作，在文件末尾附加一行文字：

Using sw As StreamWriter = File.AppendText("politicalparties.txt")
    sw.WriteLine(party & ", " & age)
End Using 

如果该文件尚不存在，则会创建该文件。