Open a file, read text and display in a listbox

Plumebee

Hi, I am very new to programming and have just started to use Visual Basic 2005 Express Edition. I am trying to read from a text file to draw a rectangles and lines. However to begin I'm trying to get the information to show in a listbox so that I know the application is reading the file correctly. I seem to be able to open the file but it doesn't display anything in the listbox.

Expand|Select|Wrap|Line Numbers

 Dim FileName As String

        Dim reader As System.IO.StreamReader
 
        uieOpenFileDialog.InitialDirectory = "C:\"

        uieOpenFileDialog.Title = "Open a File"

        uieOpenFileDialog.Filter = "Text Files(*.txt)|*.txt|All Files(*.*)|*.*"

        uieOpenFileDialog.ShowDialog()
 
        MsgBox(FileName)

        Dim DidWork As Integer = uieOpenFileDialog.ShowDialog()

        If DidWork = DialogResult.Cancel Then

            MsgBox("Cancel Button Clicked")

        Else

            FileName = uieOpenFileDialog.FileName

            MsgBox(FileName)

        End If
 
        reader = System.IO.File.OpenText(uieOpenFileDialog.FileName)

        Dim shape As String

        Dim code As Integer
 
        Try

            Me.ListBox1.Items.Clear()
 
            Do While reader.Peek <> -1

                shape = reader.ReadLine

                If shape = "Rectangle" Then

                    Select Case code

                        Case 1
 
                            rect.X = Convert.ToInt32(reader.ReadLine)

                            rect.Y = Convert.ToInt32(reader.ReadLine)

                            rect.Width = Convert.ToInt32(reader.ReadLine)

                            rect.Height = Convert.ToInt32(reader.ReadLine)
 
                            ListBox1.Items.Add()
 
                        Case 2

                            rect.X = Convert.ToInt32(reader.ReadLine)

                            rect.Y = Convert.ToInt32(reader.ReadLine)

                            rect.Width = Convert.ToInt32(reader.ReadLine)

                            rect.Height = Convert.ToInt32(reader.ReadLine)
 
                            ListBox1.Items.Add
 
                    End Select

                Else

                End If

            Loop

        Catch

            Me.ListBox1.Items.Add("file is empty")

        End Try

        reader.Close()

    End Sub

The error code I'm receiving is: Error 1 Argument not specified for parameter 'item' of 'Public Function Add(item As Object) As Integer'.

Teme64

You should add something to ListBox when you're using Add method (lines 36 and 45). Change lines to following:

Expand|Select|Wrap|Line Numbers

 ListBox1.Items.Add("Code=" & code &  ", Rect.X=" & rect.X & ", Rect.Y=" & rect.Y & ", Rect.Width=" & rect.Width & ", Rect.Height=" & rect.Height)
 
 

and you'll see what you read from your file.

rpicilli

Hi friend.

Give a example of the line you have in this file text this way I could help you.

Your code is missing information. For example:

shape = reader.ReadLine
If shape = "Rectangle" Then
Select Case code *******You never put any value in code always is 0 (zero)
Case 1
****Convert the same value in this 4 lines. This will give you a DOT on screen
rect.X = Convert.ToInt32(reader.ReadLine)
rect.Y = Convert.ToInt32(reader.ReadLine)
rect.Width = Convert.ToInt32(reader.ReadLine)
rect.Height = Convert.ToInt32(reader.ReadLine)

ListBox1.Items.Add()

Case 2
rect.X = Convert.ToInt32(reader.ReadLine)
rect.Y = Convert.ToInt32(reader.ReadLine)
rect.Width = Convert.ToInt32(reader.ReadLine)
rect.Height = Convert.ToInt32(reader.ReadLine)

***here you are adding nothing to the listbox1
ListBox1.Items.Add

End Select
Else
End If

Put here a line of the text file that I'll help you.

Rogerio

Open a file, read text and display in a listbox

re: Open a file, read text and display in a listbox

re: Open a file, read text and display in a listbox

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