How to refresh the data in an XMLReader object
Public Class Form1
Inherits System.Windows.Forms.Form
'Dataset used to read data in from files
Dim dsTicker As New DataSet("Ticker")
'XML Reader used to read data from dataset and
'handle it
Dim xmlReader As New Xml.XmlDataDocument()
'Path to xml file
Const strTickerPath = "http://www.vastock.com/raw/ticker.xml"
'String used to hold xml read from file, to pass to the xml reader
Dim strCurrentXML As String
'Strings used to hold information about the stock
Dim strCurrentStockName As String
Dim strCurrentStockPrice As String
Dim strCurrentStockChange As String
'Integer used to loop through records
Dim intCurrentRow As Integer = 0
Dim intCurrentLoop
Dim intTickerSpeed As Integer = 100
Dim strTickerText As String
Dim strWatchListOn As Boolean
Dim strWatchList As String
Dim strWatchListData As String
Dim i As Long
Dim WatchArray As Array
#Region " Windows Form Designer generated code "
Public Sub New()
MyBase.New()
'This call is required by the Windows Form Designer.
InitializeComponent()
'Add any initialization after the InitializeComponent() call
End Sub
'Form overrides dispose to clean up the component list.
Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
If disposing Then
If Not (components Is Nothing) Then
components.Dispose()
End If
End If
MyBase.Dispose(disposing)
End Sub
'Required by the Windows Form Designer
Private components As System.ComponentModel.IContainer
'NOTE: The following procedure is required by the Windows Form Designer
'It can be modified using the Windows Form Designer.
'Do not modify it using the code editor.
Friend WithEvents mnuMain As System.Windows.Forms.MainMenu
Friend WithEvents MenuItem1 As System.Windows.Forms.MenuItem
Friend WithEvents MenuItem4 As System.Windows.Forms.MenuItem
Friend WithEvents MenuItem5 As System.Windows.Forms.MenuItem
Friend WithEvents MenuItem7 As System.Windows.Forms.MenuItem
Friend WithEvents tmrScroll As System.Windows.Forms.Timer
Friend WithEvents lblTicker As System.Windows.Forms.RichTextBox
Friend WithEvents MenuItem2 As System.Windows.Forms.MenuItem
Friend WithEvents MenuItem3 As System.Windows.Forms.MenuItem
<System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
Me.components = New System.ComponentModel.Container()
Me.mnuMain = New System.Windows.Forms.MainMenu()
Me.MenuItem1 = New System.Windows.Forms.MenuItem()
Me.MenuItem4 = New System.Windows.Forms.MenuItem()
Me.MenuItem5 = New System.Windows.Forms.MenuItem()
Me.MenuItem7 = New System.Windows.Forms.MenuItem()
Me.MenuItem2 = New System.Windows.Forms.MenuItem()
Me.tmrScroll = New System.Windows.Forms.Timer(Me.components)
Me.lblTicker = New System.Windows.Forms.RichTextBox()
Me.MenuItem3 = New System.Windows.Forms.MenuItem()
Me.SuspendLayout()
'
'mnuMain
'
Me.mnuMain.MenuItems.AddRange(New System.Windows.Forms.MenuItem()
{Me.MenuItem1, Me.MenuItem5})
'
'MenuItem1
'
Me.MenuItem1.Index = 0
Me.MenuItem1.MenuItems.AddRange(New System.Windows.Forms.MenuItem()
{Me.MenuItem4})
Me.MenuItem1.Text = "&File"
'
'MenuItem4
'
Me.MenuItem4.Index = 0
Me.MenuItem4.Text = "Exit"
'
'MenuItem5
'
Me.MenuItem5.Index = 1
Me.MenuItem5.MenuItems.AddRange(New System.Windows.Forms.MenuItem()
{Me.MenuItem7, Me.MenuItem2, Me.MenuItem3})
Me.MenuItem5.Text = "&Application"
'
'MenuItem7
'
Me.MenuItem7.Index = 0
Me.MenuItem7.Text = "A&bout"
'
'MenuItem2
'
Me.MenuItem2.Index = 1
Me.MenuItem2.Text = "&Configuration"
'
'tmrScroll
'
Me.tmrScroll.Enabled = True
'
'lblTicker
'
Me.lblTicker.BorderStyle = System.Windows.Forms.BorderStyle.None
Me.lblTicker.Dock = System.Windows.Forms.DockStyle.Fill
Me.lblTicker.Font = New System.Drawing.Font("Courier New", 8.25!,
System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point,
CType(0, Byte))
Me.lblTicker.Multiline = False
Me.lblTicker.Name = "lblTicker"
Me.lblTicker.ReadOnly = True
Me.lblTicker.ScrollBars = System.Windows.Forms.RichTextBoxScrollBars.None
Me.lblTicker.Size = New System.Drawing.Size(824, 12)
Me.lblTicker.TabIndex = 0
Me.lblTicker.Text = ""
'
'MenuItem3
'
Me.MenuItem3.Index = 2
Me.MenuItem3.Text = "Stock &Watchlist"
'
'Form1
'
Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
Me.ClientSize = New System.Drawing.Size(824, 12)
Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.lblTicker})
Me.ForeColor = System.Drawing.SystemColors.ControlLight
Me.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedToolWindow
Me.MaximizeBox = False
Me.Menu = Me.mnuMain
Me.MinimizeBox = False
Me.Name = "Form1"
Me.ShowInTaskbar = False
Me.StartPosition = System.Windows.Forms.FormStartPosition.Manual
Me.Text = "Virtual Airline Stock Market - Stock Ticker"
Me.TopMost = True
Me.ResumeLayout(False)
End Sub
#End Region
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles MyBase.Load
'Show loading window
Dim LoadingForm As New Loading()
LoadingForm.Show()
'Set the ticker to be 10 pixels less than the window size.
lblTicker.Width = Me.Width - 10
'Refresh Ticker
LoadTickerData()
InsertTickerData()
'Set size
Me.Width = Screen.FromControl(Me).GetWorkingArea(Me).Width
tmrScroll.Interval = intTickerSpeed
'Set the ticker to be 10 pixels less than the window size.
lblTicker.Width = Me.Width - 10
Dim temp As New Form()
MaintainSize(temp)
LoadingForm.Close()
End Sub
Private Sub InsertTickerData()
strWatchList = ""
For intCurrentLoop = 1 To
xmlReader.ChildNodes(0).ChildNodes(1).ChildNodes.Count - 1
'Load data into strings, using indices to navigate - 0 being the first node
meaning:
'xmlReader.ChildNodes(0) is navigating to the <ticker> element
'xmlReader.ChildNodes(0).ChildNodes(1) is navigating to the <data> element
'xmlReader.ChildNodes(0).ChildNodes(1).ChildNodes(0) is navigating to the
<entry> element
'xmlReader.ChildNodes(0).ChildNodes(1).ChildNodes(0).ChildNodes(n) is
navigating to:
'0 = Stock Name
'1 = Stock Price
'2 = Stock Price Change
'Then .InnerText simply reads the data from that node.
strCurrentStockName =
xmlReader.ChildNodes(0).ChildNodes(1).ChildNodes(intCurrentRow).ChildNodes(0
).InnerText
strCurrentStockPrice =
xmlReader.ChildNodes(0).ChildNodes(1).ChildNodes(intCurrentRow).ChildNodes(1
).InnerText
strCurrentStockChange =
xmlReader.ChildNodes(0).ChildNodes(1).ChildNodes(intCurrentRow).ChildNodes(2
).InnerText
If strWatchListOn = "1" Then
For i = 0 To WatchArray.GetUpperBound(0)
If strCurrentStockName = WatchArray(i) Then
strWatchList &= strCurrentStockName
strWatchList &= " Price: v$" & strCurrentStockPrice
strWatchList &= " Change: v$"
strWatchList &= " | "
End If
Next
End If
lblTicker.Text &= strCurrentStockName
lblTicker.Text &= " Price: v$" & strCurrentStockPrice
lblTicker.Text &= " Change: " & strCurrentStockChange
lblTicker.Text &= " | "
intCurrentRow = intCurrentRow + 1
Next
strTickerText = lblTicker.Text
End Sub
Private Sub LoadTickerData()
'Read the xml file into the dataset
dsTicker.ReadXml(strTickerPath)
'Set the string to the ACTUAL XML - not the data
strCurrentXML = dsTicker.GetXml
'Load that string/xml into the xmlReader for handling
xmlReader.LoadXml(strCurrentXML)
End Sub
Private Sub MenuItem4_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles MenuItem4.Click
'Exit Program
End
End Sub
Private Sub MaintainSize(ByVal frmTicker As Form)
Dim BoundRec As Rectangle = Screen.GetBounds(frmTicker)
Me.Width = BoundRec.Width
Me.Height = 64
Me.Left = 0
Me.Top = 0
End Sub
Private Sub Form1_Resize(ByVal sender As Object, ByVal e As
System.EventArgs) Handles MyBase.Resize
'Set the ticker to be 10 pixels less than the window size.
lblTicker.Width = Me.Width - 10
Dim temp As New Form()
MaintainSize(temp)
End Sub
Private Sub tmrScroll_Tick(ByVal sender As Object, ByVal e As
System.EventArgs) Handles tmrScroll.Tick
If lblTicker.Text = "" Then
lblTicker.Text = strTickerText
Else
lblTicker.Text = Mid(lblTicker.Text, 2)
End If
Dim temp As New Form()
MaintainSize(temp)
End Sub
Private Sub MenuItem7_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles MenuItem7.Click
'Load about form
Dim AboutForm As New About()
AboutForm.Show()
End Sub
Private Sub MenuItem2_Click_1(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles MenuItem2.Click
intTickerSpeed = InputBox("Please enter the speed for the ticker (characters
per interval):")
tmrScroll.Interval = intTickerSpeed
End Sub
Private Sub MenuItem3_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles MenuItem3.Click
End Sub
End Class
