Add a Google Map to a VB Desktop Application

Code:  Form 1

The form 1 class starts out with the default class declaration. An import statement was added to pull in the System.Text library; this is required to support the use of string builders within the application.

Imports System.Text

Public Class Form1

Following the class declaration, the next bit of code in the class is used to handle the button click event that requests a map of a physical address from Google Maps; that code is as follows: 

''' <summary>

''' Map a physical address

''' </summary>

''' <param name="sender"></param>

''' <param name="e"></param>

''' <remarks></remarks>

Private Sub btnMapIt_Click(ByVal sender As System.Object, ByVal e As

System.EventArgs) Handles btnMapIt.Click

    Try

        Dim street As String = String.Empty

        Dim city As String = String.Empty

        Dim state As String = String.Empty

        Dim zip As String = String.Empty

        Dim queryAddress As New StringBuilder()

        queryAddress.Append("http://maps.google.com/maps?q=")

        ' build street part of query string

        If txtStreet.Text <> String.Empty Then

            street = txtStreet.Text.Replace(" ", "+")

            queryAddress.Append(street + "," & "+")

        End If

        ' build city part of query string

        If txtCity.Text <> String.Empty Then

            city = txtCity.Text.Replace(" ", "+")

            queryAddress.Append(city + "," & "+")

        End If

        ' build state part of query string

        If txtState.Text <> String.Empty Then

            state = txtState.Text.Replace(" ", "+")

            queryAddress.Append(state + "," & "+")

        End If

        ' build zip code part of query string

        If txtZipCode.Text <> String.Empty Then

            zip = txtZipCode.Text.ToString()

            queryAddress.Append(zip)

        End If

        ' pass the url with the query string to web browser control

        webBrowser1.Navigate(queryAddress.ToString())

    Catch ex As Exception

        MessageBox.Show(ex.Message.ToString(), "Unable to Retrieve Map")

    End Try

End Sub 

A quick examination of this code reveals that the contents of the text boxes used to define the physical address are captured from the form and used to populate variables local to the event handler. A string builder is used to build the URL and query string. 

Once the string builder is initialized, the first part of the URL is appended to it. As each additional section of the address is conditioned for use in the query string, it too is appended to the query string. Once the string is defined, it is passed to the web browser control as its navigate URL. At that point, the web browser will display the address if it can be found or will summon Goggle Maps with optional selections used to narrow down to a single address.

The next bit of code in the application performs a similar function with Latitudes and Longitudes; the click event handler for the button is used to evoke the map based upon the user supplied lat/long values. That code is as follows: 

''' <summary>

''' Map a location by latitude and longitude

''' </summary>

''' <param name="sender"></param>

''' <param name="e"></param>

''' <remarks></remarks>

Private Sub btnMapLatLong_Click(ByVal sender As System.Object, ByVal e As 

System.EventArgs) Handles btnMapLatLong.Click

    If txtLat.Text = String.Empty Or txtLong.Text = String.Empty Then

        MessageBox.Show("Supply a latitude and longitude value.", "Missing Data")

    End If

    Try

        Dim lat As String = String.Empty

        Dim lon As String = String.Empty

        Dim queryAddress As New StringBuilder()

        queryAddress.Append("http://maps.google.com/maps?q=")

        ' build latitude part of query string

        If txtLat.Text <> String.Empty Then

            lat = txtLat.Text

            queryAddress.Append(lat + "%2C")

        End If

        ' build longitude part of query string

        If txtLong.Text <> String.Empty Then

            lon = txtLong.Text

            queryAddress.Append(lon)

        End If

        webBrowser1.Navigate(queryAddress.ToString())

    Catch ex As Exception

        MessageBox.Show(ex.Message.ToString(), "Error")

    End Try

End Sub