Imports System.IO

Public Class CreateFile
    Inherits System.Web.UI.Page
    Protected WithEvents TextBox1 As System.Web.UI.WebControls.TextBox
    Protected WithEvents Label2 As System.Web.UI.WebControls.Label
    Protected WithEvents DropDownList1 As System.Web.UI.WebControls.DropDownList
    Protected WithEvents btnDelete As System.Web.UI.WebControls.Button
    Protected WithEvents btnCreate As System.Web.UI.WebControls.Button
    Protected WithEvents btnDisplay As System.Web.UI.WebControls.Button
    Protected WithEvents Label3 As System.Web.UI.WebControls.Label
    Protected WithEvents Label1 As System.Web.UI.WebControls.Label

#Region " Web Form Designer Generated Code "

    'This call is required by the Web Form Designer.
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()

    End Sub

    Private Sub Page_Init(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Init
        'CODEGEN: This method call is required by the Web Form Designer
        'Do not modify it using the code editor.
        InitializeComponent()
    End Sub

#End Region

    Dim MyPath As String
    Dim MyFile As String
    Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        'Put user code to initialize the page here
        MyPath = "c:\Inetpub\wwwroot\Chapter12\Users\"
      
        If Not Page.IsPostBack Then
            Label1.Text = _
            "Enter the name of the file to create."
            Call DisplayFiles(MyPath)
            DropDownList1.Visible = False
            btnDelete.Visible = False
            btnDisplay.Visible = False
            Label3.Visible = False
        Else
            DropDownList1.Visible = True
            btnDelete.Visible = True
            btnDisplay.Visible = True
            Label3.Visible = True
            Try
                MyFile = MyPath & DropDownList1.SelectedItem.ToString
            Catch exc As NullReferenceException
            Catch exc As ArgumentNullException
            End Try

            Call DisplayFiles(MyPath)
        End If
 
    End Sub

    Public Function DisplayFiles(ByVal MyPath)
        Dim DDL As DirectoryInfo = _
            New DirectoryInfo(MyPath)
        Dim MyFile As FileInfo
        Dim MyHash As New Hashtable
        For Each MyFile In DDL.GetFiles()
            MyHash.Add(MyFile.Name, MyFile.Name)
        Next
        DropDownList1.DataTextField = "Key"
        DropDownList1.DataValueField = "Value"
        DropDownList1.DataSource = MyHash
        DropDownList1.DataBind()

    End Function
 

    Private Sub btnCreate_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCreate.Click
        Try
            ' Insert the code here 















            Label1.Text = "The <b>" & TextBox1.Text & _
                             " </b>file was created successfully."

        Catch exc As ArgumentException
            Label1.Text = "You must enter a valid name to create a file."
        Catch exc As ArgumentNullException
            Label1.Text = "You must enter a name to create a file."
        Catch exc As IOException
            Label1.Text = "The file already exists."
        Catch exc As PathTooLongException
            Label1.Text = "The file name is to long."
        End Try

        TextBox1.Text = ""
        DisplayFiles(MyPath)
    End Sub

    Private Sub btnDelete_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDelete.Click
        Try
            ' Insert the code here 












        Catch exc As ArgumentNullException
            Label1.Text = "You must specify a file to delete."
        Catch exc As NullReferenceException
            Label1.Text = "You must specify a file to delete."
        Catch exc As UnauthorizedAccessException
            Label1.Text = "You are not authorized to delete this file."
        End Try
        TextBox1.Text = ""
        DisplayFiles(MyPath)

    End Sub

    Private Sub btnDisplay_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDisplay.Click
        Label3.Text = ""
        Try
            ' Insert the code here 









        Catch exc As ArgumentNullException
            Label1.Text = "You must select a file that exists."
        End Try

        DisplayFiles(MyPath)
    End Sub
End Class