Click here to Skip to main content
Click here to Skip to main content

Embedding Google Earth in a C# Application

, 8 Dec 2008 LGPL3
Rate this:
Please Sign up or sign in to vote.
How to embed the Google Earth scene in a C# application.

Introduction

If you're interested in utilizing the Google Earth viewer as a control in a custom application, then continue reading. There are quite a few links around the Internet that provide information as to how to add references to your project, create a ApplicationGE, and control the Google Earth application. However, most of these tutorials do not focus on the details of embedding Google Earth in an application. That's what I will focus on here. From now on, GE means Google Earth.

The Code

You'll probably start off on your embedding adventure much like I did, with:

EARTHLib.ApplicationGE ge = new ApplicationGEClass();

If the GE process already exists, we will obtain a reference to it; if not, a new process will be created, and you would see the GE logo flash on the screen while loading. You will then see the main Google Earth screen with the embedded viewer. Since we are interested in embedding GE, we are not interested in having the main screen around, so we hide it!

ShowWindowAsync(ge.GetMainHwnd(), 0);

For all intensive purposes, we now have an empty screen. What we'd like to do next is embed the scene that GE renders into our application. We accomplish this by setting the render Hwnds parent to that of the window we would like to render to:

SetParent(ge.GetRenderHwnd(), this.Handle.ToInt32());

In the example above, 'this' is a Windows Form. The end result, if you perform these same steps, should look similar to the image below, although I do warn that results may vary Smile | :)

google_earth_embedded.jpg

You will notice that resizing the window has no effect on the scene. If you plan on embedding GE in an application for any useful purposes, you'll most likely need it to respond to resizing. I spent a bit of time sniffing into the events that were passed to the scene when I performed re-size of the main GE application window. This led me to a special event, WM_QT_PAINT, in addition to a sequence of others. It took a bit of tinkering to get it all right, but this appeared to work for me:

SendMessage(ge.GetMainHwnd(), WM_COMMAND, WM_PAINT, 0);
PostMessage(ge.GetMainHwnd(), WM_QT_PAINT, 0, 0);
SetWindowPos( ge.GetMainHwnd(), HWND_TOP, 0, 0, (int)this.Width, 
             (int)this.Height, SWP_FRAMECHANGED);
SendMessage(ge.GetRenderHwnd(), WM_COMMAND, WM_SIZE, 0);

This should allow the scene to adjust according to the parent form's size. I bundled this up into a method named "ResizeGoogleControl", and called it after SetParent and within my Form_Resize event. The results are illustrated in this image:

google_earth_embedded_good.jpg

The Example

I slapped together a test app that you are welcome to use for reference. If you have any comments or suggestions, be sure to send me an email or add a comment. Create a new C# project in Visual Studio and replace the Form1.cs code with this:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Runtime.InteropServices;
using System.Text;
using System.Windows.Forms;

using EARTHLib;

namespace resize_google_earth
{

public partial class Form1 : Form
{
    [DllImport("user32.dll")]
    private static extern int SetParent(
    int hWndChild,
    int hWndParent);

    [DllImport("user32.dll")]
    private static extern bool ShowWindowAsync(
    int hWnd,
    int nCmdShow);

    [DllImport("user32.dll", SetLastError = true)]
    private static extern bool PostMessage(
    int hWnd,
    uint Msg,
    int wParam,
    int lParam);

    [DllImport("user32.dll", EntryPoint = "SetWindowPos")]
    private static extern bool SetWindowPos(
    int hWnd,
    int hWndInsertAfter,
    int X,
    int Y,
    int cx,
    int cy,
    uint uFlags);

    [DllImport("user32.dll")]
    private static extern int SendMessage(
    int hWnd,
    uint Msg,
    int wParam,
    int lParam);

    private const int HWND_TOP = 0x0;
    private const int WM_COMMAND = 0x0112;
    private const int WM_QT_PAINT = 0xC2DC;
    private const int WM_PAINT = 0x000F;
    private const int WM_SIZE = 0x0005;
    private const int SWP_FRAMECHANGED = 0x0020;

    public Form1()
    {
        InitializeComponent();

        ge = new ApplicationGEClass();

        ShowWindowAsync(ge.GetMainHwnd(), 0);
        SetParent(ge.GetRenderHwnd(), this.Handle.ToInt32());
        ResizeGoogleControl();
    }

    private void Form1_Resize(object sender, EventArgs e)
    {
        ResizeGoogleControl();
    }

    private void ResizeGoogleControl()
    {
        SendMessage(ge.GetMainHwnd(), WM_COMMAND, WM_PAINT, 0);
        PostMessage(ge.GetMainHwnd(), WM_QT_PAINT, 0, 0);

        SetWindowPos(
        ge.GetMainHwnd(),
        HWND_TOP,
        0,
        0,
        (int)this.Width,
        (int)this.Height,
        SWP_FRAMECHANGED);

        SendMessage(ge.GetRenderHwnd(), WM_COMMAND, WM_SIZE, 0);
    }

    private EARTHLib.ApplicationGE ge = null;
}
}

License

This article, along with any associated source code and files, is licensed under The GNU Lesser General Public License (LGPLv3)

Share

About the Author

Joseph Armbruster
Software Developer
United States United States
I love to write programs and vim is my editor of choice. Programming languages fascinate me and I feel at least reasonably familiar with C, python, C++, JAVA, C#, ECMAScript, Lua and Ruby. I also use a few open source relational database systems; postgresql, mysql, sqlite. Some of my interests include: programming languages, geoprocessing, number theory, network protocols, web services, cryptography, linux, windows, open source, GIS.
 
See: http://www.joevial.com

Comments and Discussions

 
QuestionSome Questions PinmemberMollaahmadi8-Sep-14 20:49 
BugGoogleEarth process isn't closed after form closing! PinmemberMember 1088091513-Jun-14 3:11 
GeneralRe: GoogleEarth process isn't closed after form closing! PinmemberZibusiso22-Aug-14 3:31 
QuestionAn errors occured while building PinmemberMember 1088091513-Jun-14 0:39 
AnswerRe: An errors occured while building PinmemberMember 1088091513-Jun-14 2:27 
QuestionPlease post LAT and LONG example for specific location.... Pinmemberzeeshan00917-Apr-14 10:38 
AnswerRe: Please post LAT and LONG example for specific location.... PinmemberMember 1088091513-Jun-14 3:41 
QuestionEARTHLib PinmemberMember 105766996-Feb-14 5:30 
AnswerRe: EARTHLib Pinmembernamth2994-Apr-14 23:34 
QuestionForm not loading Google Earth PinmemberMember 842394629-Apr-13 11:09 
QuestionAdd GPS Pinmember3nZo23-Apr-13 2:37 
QuestionDear Sir, PinmemberEthiopaninomaltt23-Feb-13 3:51 
QuestionHow to get Coordiantes from cursor PinmemberM.S.S.E22-Jan-13 0:57 
QuestionWPF Compatibilty PinmemberMember 960766617-Nov-12 9:23 
QuestionThis demo just open once , GE dont run in second Pinmembershindo2165-Sep-12 18:48 
AnswerRe: This demo just open once , GE dont run in second Pinmembershindo2165-Sep-12 19:21 
GeneralRe: This demo just open once , GE dont run in second Pinmemberraddog14-Jan-13 13:54 
QuestionMouse wheel zoom in/out doesn't work? [modified] Pinmembersherifffruitfly23-Aug-12 19:40 
Questionplace mark icon Pinmembermojimoj18-Mar-12 9:52 
QuestionHi Pinmembermyazar16-Nov-11 10:31 
GeneralMy vote of 4 Pinmemberspicolihill@hotmail.com27-May-11 12:44 
Generalx64 (64bit) machines Pinmemberth3_v0ice1-May-11 7:10 
GeneralInitializeComponent() Pinmembernat0626-Jan-11 22:00 
GeneralRe: InitializeComponent() PinmemberRayChenMedical21-Apr-11 7:25 
GeneralEARTHLib; Pinmembermostafa.elsadany7-Jan-11 5:28 

General General    News News    Suggestion Suggestion    Question Question    Bug Bug    Answer Answer    Joke Joke    Rant Rant    Admin Admin   

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.

| Advertise | Privacy | Terms of Use | Mobile
Web04 | 2.8.1411019.1 | Last Updated 8 Dec 2008
Article Copyright 2008 by Joseph Armbruster
Everything else Copyright © CodeProject, 1999-2014
Layout: fixed | fluid