vb google maps specific location - vb.net

Question

Imports System.Windows.Threading
Imports System.Threading
Imports System.Net
Imports System.Drawing
Imports System.IO
Imports Microsoft.Win32
Class Window1
#Region "Fields"
Private geoDoc As XDocument
Private location As String
Private zoom As Integer
Private saveDialog As New SaveFileDialog
Private mapType As String
Private lat As Double
Private lng As Double
#End Region
Private Sub GetGeocodeData()
Dim geocodeURL As String = "http://maps.googleapis.com/maps/api/" & _
"geocode/xml?address=" & location & "&sensor=false"
Try
geoDoc = XDocument.Load(geocodeURL)
Catch ex As WebException
Me.Dispatcher.BeginInvoke(New ThreadStart(AddressOf HideProgressBar), _
DispatcherPriority.Normal, Nothing)
MessageBox.Show("Ensure that internet connection is available.", _
"Map App", MessageBoxButton.OK, MessageBoxImage.Error)
Exit Sub
End Try
Me.Dispatcher.BeginInvoke(New ThreadStart(AddressOf ShowGeocodeData), _
DispatcherPriority.Normal, Nothing)
End Sub
Private Sub ShowGeocodeData()
Dim responseStatus = geoDoc...<status>.Single.Value()
If (responseStatus = "OK") Then
Dim formattedAddress = geoDoc...<formatted_address>(0).Value()
Dim latitude = geoDoc...<location>(0).Element("lat").Value()
Dim longitude = geoDoc...<location>(0).Element("lng").Value()
Dim locationType = geoDoc...<location_type>(0).Value()
AddressTxtBlck.Text = formattedAddress
LatitudeTxtBlck.Text = latitude
LongitudeTxtBlck.Text = longitude
Select Case locationType
Case "APPROXIMATE"
AccuracyTxtBlck.Text = "Approximate"
Case "ROOFTOP"
AccuracyTxtBlck.Text = "Precise"
Case Else
AccuracyTxtBlck.Text = "Approximate"
End Select
lat = Double.Parse(latitude)
lng = Double.Parse(longitude)
If (SaveButton.IsEnabled = False) Then
SaveButton.IsEnabled = True
RoadmapToggleButton.IsEnabled = True
TerrainToggleButton.IsEnabled = True
End If
ElseIf (responseStatus = "ZERO_RESULTS") Then
MessageBox.Show("Unable to show results for: " & vbCrLf & _
location, "Unknown Location", MessageBoxButton.OK, _
MessageBoxImage.Information)
DisplayXXXXXXs()
AddressTxtBox.SelectAll()
End If
ShowMapButton.IsEnabled = True
ZoomInButton.IsEnabled = True
ZoomOutButton.IsEnabled = True
MapProgressBar.Visibility = Windows.Visibility.Hidden
End Sub
' Get and display map image in Image ctrl.
Private Sub ShowMapImage()
Dim bmpImage As New BitmapImage()
Dim mapURL As String = "http://maps.googleapis.com/maps/api/staticmap?" & _
"size=500x400&markers=size:mid%7Ccolor:red%7C" & _
location & "&zoom=" & zoom & "&maptype=" & mapType & "&sensor=false"
bmpImage.BeginInit()
bmpImage.UriSource = New Uri(mapURL)
bmpImage.EndInit()
MapImage.Source = bmpImage
End Sub
Private Sub ShowMapUsingLatLng()
Dim bmpImage As New BitmapImage()
Dim mapURL As String = "http://maps.googleapis.com/maps/api/staticmap?" & _
"center=" & lat & "," & lng & "&" & _
"size=500x400&markers=size:mid%7Ccolor:red%7C" & _
location & "&zoom=" & zoom & "&maptype=" & mapType & "&sensor=false"
bmpImage.BeginInit()
bmpImage.UriSource = New Uri(mapURL)
bmpImage.EndInit()
MapImage.Source = bmpImage
End Sub
' Zoom-in on map.
Private Sub ZoomIn()
If (zoom < 21) Then
zoom += 1
ShowMapUsingLatLng()
If (ZoomOutButton.IsEnabled = False) Then
ZoomOutButton.IsEnabled = True
End If
Else
ZoomInButton.IsEnabled = False
End If
End Sub
' Zoom-out on map.
Private Sub ZoomOut()
If (zoom > 0) Then
zoom -= 1
ShowMapUsingLatLng()
If (ZoomInButton.IsEnabled = False) Then
ZoomInButton.IsEnabled = True
End If
Else
ZoomOutButton.IsEnabled = False
End If
End Sub
Private Sub SaveMap()
Dim mapURL As String = "http://maps.googleapis.com/maps/api/staticmap?" & _
"center=" & lat & "," & lng & "&" & _
"size=500x400&markers=size:mid%7Ccolor:red%7C" & _
location & "&zoom=" & zoom & "&maptype=" & mapType & "&sensor=false"
Dim webClient As New WebClient()
Try
Dim imageBytes() As Byte = webClient.DownloadData(mapURL)
Using ms As New MemoryStream(imageBytes)
Image.FromStream(ms).Save(saveDialog.FileName, Imaging.ImageFormat.Png)
End Using
Catch ex As WebException
MessageBox.Show("Unable to save map. Ensure that you are" & _
" connected to the internet.", "Error!", _
MessageBoxButton.OK, MessageBoxImage.Stop)
Exit Sub
End Try
End Sub
Private Sub MoveUp()
' Default zoom is 15 and at this level changing
' the center point is done by 0.003 degrees.
' Shifting the center point is done by higher values
' at zoom levels less than 15.
Dim diff As Double
Dim shift As Double
' Use 88 to avoid values beyond 90 degrees of lat.
If (lat < 88) Then
If (zoom = 15) Then
lat += 0.003
ElseIf (zoom > 15) Then
diff = zoom - 15
shift = ((15 - diff) * 0.003) / 15
lat += shift
Else
diff = 15 - zoom
shift = ((15 + diff) * 0.003) / 15
lat += shift
End If
ShowMapUsingLatLng()
Else
lat = 90
End If
End Sub
Private Sub MoveDown()
Dim diff As Double
Dim shift As Double
If (lat > -88) Then
If (zoom = 15) Then
lat -= 0.003
ElseIf (zoom > 15) Then
diff = zoom - 15
shift = ((15 - diff) * 0.003) / 15
lat -= shift
Else
diff = 15 - zoom
shift = ((15 + diff) * 0.003) / 15
lat -= shift
End If
ShowMapUsingLatLng()
Else
lat = -90
End If
End Sub
Private Sub MoveLeft()
Dim diff As Double
Dim shift As Double
' Use -178 to avoid negative values below -180.
If (lng > -178) Then
If (zoom = 15) Then
lng -= 0.003
ElseIf (zoom > 15) Then
diff = zoom - 15
shift = ((15 - diff) * 0.003) / 15
lng -= shift
Else
diff = 15 - zoom
shift = ((15 + diff) * 0.003) / 15
lng -= shift
End If
ShowMapUsingLatLng()
Else
lng = 180
End If
End Sub
Private Sub MoveRight()
Dim diff As Double
Dim shift As Double
If (lng < 178) Then
If (zoom = 15) Then
lng += 0.003
ElseIf (zoom > 15) Then
diff = zoom - 15
shift = ((15 - diff) * 0.003) / 15
lng += shift
Else
diff = 15 - zoom
shift = ((15 + diff) * 0.003) / 15
lng += shift
End If
ShowMapUsingLatLng()
Else
lng = -180
End If
End Sub
Private Sub DisplayXXXXXXs()
AddressTxtBlck.Text = "XXXXXXXXX, XXXXX, XXXXXX"
LatitudeTxtBlck.Text = "XXXXXXXXXX"
LongitudeTxtBlck.Text = "XXXXXXXXXX"
AccuracyTxtBlck.Text = "XXXXXXXXX"
End Sub
Private Sub HideProgressBar()
MapProgressBar.Visibility = Windows.Visibility.Hidden
ShowMapButton.IsEnabled = True
End Sub
' ShowMapButton click event handler.
Private Sub ShowMapButton_Click(ByVal sender As Object, ByVal e As System.Windows.RoutedEventArgs) Handles ShowMapButton.Click
If (AddressTxtBox.Text <> String.Empty) Then
location = AddressTxtBox.Text.Replace(" ", "+")
zoom = 15
mapType = "roadmap"
Dim geoThread As New Thread(AddressOf GetGeocodeData)
geoThread.Start()
ShowMapImage()
AddressTxtBox.SelectAll()
ShowMapButton.IsEnabled = False
MapProgressBar.Visibility = Windows.Visibility.Visible
If (RoadmapToggleButton.IsChecked = False) Then
RoadmapToggleButton.IsChecked = True
TerrainToggleButton.IsChecked = False
End If
Else
MessageBox.Show("Enter location address.", _
"Map App", MessageBoxButton.OK, MessageBoxImage.Exclamation)
AddressTxtBox.Focus()
End If
End Sub
' SaveFileDialog FileOk event handler.
Private Sub saveDialog_FileOk(ByVal sender As Object, ByVal e As EventArgs)
Dim td As New Thread(AddressOf SaveMap)
td.Start()
End Sub
' ZoomInButton click event handler.
Private Sub ZoomInButton_Click(ByVal sender As Object, ByVal e As System.Windows.RoutedEventArgs) Handles ZoomInButton.Click
ZoomIn()
End Sub
' ZoomOutButton click event handler.
Private Sub ZoomOutButton_Click(ByVal sender As Object, ByVal e As System.Windows.RoutedEventArgs) Handles ZoomOutButton.Click
ZoomOut()
End Sub
' SaveButton click event handler.
Private Sub SaveButton_Click(ByVal sender As Object, ByVal e As System.Windows.RoutedEventArgs) Handles SaveButton.Click
saveDialog.ShowDialog()
End Sub
' RoadmapToggleButton Checked event handler.
Private Sub RoadmapToggleButton_Checked(ByVal sender As Object, ByVal e As System.Windows.RoutedEventArgs) Handles RoadmapToggleButton.Checked
If (mapType <> "roadmap") Then
mapType = "roadmap"
ShowMapUsingLatLng()
TerrainToggleButton.IsChecked = False
End If
End Sub
' TerrainToggleButton Checked event handler.
Private Sub TerrainToggleButton_Checked(ByVal sender As Object, ByVal e As System.Windows.RoutedEventArgs) Handles TerrainToggleButton.Checked
If (mapType <> "terrain") Then
mapType = "terrain"
ShowMapUsingLatLng()
RoadmapToggleButton.IsChecked = False
End If
End Sub
Private Sub MapImage_MouseLeftButtonUp(ByVal sender As Object, ByVal e As System.Windows.Input.MouseButtonEventArgs) Handles MapImage.MouseLeftButtonUp
If (location IsNot Nothing) Then
Dim gMapURL As String = "http://maps.google.com/maps?q=" & location
Process.Start("IExplore.exe", gMapURL)
End If
End Sub
Private Sub Window1_Loaded(ByVal sender As Object, ByVal e As System.Windows.RoutedEventArgs) Handles Me.Loaded
AddressTxtBox.Focus()
With saveDialog
.DefaultExt = "png"
.Title = "Save Map Image"
.OverwritePrompt = True
.Filter = "(*.png)|*.png"
End With
AddHandler saveDialog.FileOk, AddressOf saveDialog_FileOk
End Sub
Private Sub MinimizeButton_Click(ByVal sender As Object, ByVal e As System.Windows.RoutedEventArgs) Handles MinimizeButton.Click
Me.WindowState = Windows.WindowState.Minimized
End Sub
Private Sub CloseButton_Click(ByVal sender As Object, ByVal e As System.Windows.RoutedEventArgs) Handles CloseButton.Click
Me.Close()
End Sub
//ds
Private Sub BgndRectangle_MouseLeftButtonDown(ByVal sender As Object, ByVal e As System.Windows.Input.MouseButtonEventArgs) Handles BgndRectangle.MouseLeftButtonDown
Me.DragMove()
End Sub
//df
Private Sub MoveUpButton_Click(ByVal sender As Object, ByVal e As System.Windows.RoutedEventArgs) Handles MoveUpButton.Click
MoveUp()
End Sub
//sdf
Private Sub MoveDownButton_Click(ByVal sender As Object, ByVal e As System.Windows.RoutedEventArgs) Handles MoveDownButton.Click
MoveDown()
End Sub
Private Sub MoveLeftButton_Click(ByVal sender As Object, ByVal e As System.Windows.RoutedEventArgs) Handles MoveLeftButton.Click
MoveLeft()
End Sub
Private Sub MoveRightButton_Click(ByVal sender As Object, ByVal e As System.Windows.RoutedEventArgs) Handles MoveRightButton.Click
MoveRight()
End Sub
End Class
i have this class for searching through google maps.
how can i pass it a location so that on startup it can show the given location on the map?

Answer 1

The WPF form has a loaded event, you can add some code there to load your first map:
Private Sub MainWindow_Loaded(sender As Object, e As RoutedEventArgs) Handles Me.Loaded
ShowMapButton_Click(sender, e)
End Sub
In this case I hardcoded an address into the AddressTxtBox and called Show Map. You can add whatever code you need to set up the conditions for the first map.
If the question is "How do I pass information to a form to be used when it first load" that is a much shorter post!
I don't work a lot with WPF so I'm not up on naming conventions and best practices so keep that in mind... For example the called form would not be called MainWindow!
In Winforms a method like this could be used:
Public in_StartAddress As String = ""
Private Sub MainWindow_Loaded(sender As Object, e As RoutedEventArgs) Handles Me.Loaded
If in_StartAddress.Length > 0 Then AddressTxtBox.Text = in_StartAddress
ShowMapButton_Click(sender, e)
End Sub
' calling routine on another form
Private Sub Button_Click(sender As Object, e As RoutedEventArgs)
Dim frm As New MainWindow
frm.in_StartAddress = "1600 Pensylvania Ave, Washington DC"
frm.Show()
frm = Nothing
End Sub
Look for posts on passing parameters to new forms/windows.