转：C#调用GoogleEarth COM API开发（一、二）

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原文地址：http://www.cnblogs.com/wpwen/archive/2009/02/06/1385570.html

一、准备

Google Earth提供了个人免费版、Plus版、Pro版，个人开发只安装个人免费版就可以了，如果需要更多的功能，那么只有每年上交$400购买专业版了

到目前为止，GoogleEarth的二次开发接口还比较少，功能太弱，仅仅提供了1.0的类库。

GoogleEarth COM API参考文档可以在这里找到：http://earth.google.com/comapi/index.html

C#调用COM的参考资料多如牛毛，大家可以到网上搜一下

二、例子

这里提供一个利用VS2008 + Google Earth 5.0开发一个“Hello world”程序

首先，确保已经正确安装GE，打开VS2008 ，新建一个Windows应用程序项目，在“项目”菜单中选择“添加引用…”，切换到“COM”选项卡，选择“Google Earth 1.0 Type Library”，其实就是Google Earth的主程序

在项目的引用中你可以看到已经添加了一个EARTHLib的引用，然后我们就可以调用其中的接口进行开发了。

下面就是小例子的代码（功能很简单，只有三个，打开GE，然后让GE保存一张截图，然后可以打开这个截图看看。呵呵）

1: // 功能：GE实例

2: // 描述：GE COM API 网址：http://earth.google.com/comapi/index.html

3: // 作者：温伟鹏

4: // 日期：2008-01-20

6: using System;

7: using System.Collections.Generic;

8: using System.ComponentModel;

9: using System.Data;

10: using System.Drawing;

11: using System.Text;

12: using System.Windows.Forms;

13: using EARTHLib;

14: using System.Runtime.InteropServices;

15: using System.IO;

16: using System.Diagnostics;

17:

18: namespace GEDemo

19: {

20: public partial class Form1 : Form

21: {

22: /// <summary>

23: /// 标记GE是否已经启动

24: /// </summary>

25: private bool isGeStarted = false;

26: /// <summary>

27: /// 定义GE应用程序类

28: /// </summary>

29: private ApplicationGEClass GeApp;

30:

31: public Form1()

32: {

33: InitializeComponent();

34: }

35:

36: private void button1_Click(object sender, EventArgs e)

37: {

38: StartGE();

39: }

40:

41: /// <summary>

42: /// 启动GE

43: /// </summary>

44: private void StartGE()

45: {

46: if (isGeStarted)

47: {

48: return;

49: }

50:

51: try

52: {

53: GeApp = (ApplicationGEClass)Marshal.GetActiveObject("GoogleEarth.Application");

54:

55: isGeStarted = true;

56: }

57: catch

58: {

59: GeApp = new ApplicationGEClass();

60:

61: isGeStarted = true;

62: }

63: }

64:

65: private void button2_Click(object sender, EventArgs e)

66: {

67: string ssFile = Path.Combine(Application.StartupPath, "ScreenShot.jpg");

68:

69: try

70: {

71: //quality的取值范围在(0,100)之间，质量越高，quality越大

72: GeApp.SaveScreenShot(ssFile, 100);

73:

74: MessageBox.Show("成功保存截屏图像：" + ssFile);

75: }

76: catch(Exception ex)

77: {

78: MessageBox.Show("保存截屏图像时发生错误：" + ex.Message);

79: }

80: }

81:

82: private void button3_Click(object sender, EventArgs e)

83: {

84: string ssFile = Path.Combine(Application.StartupPath, "ScreenShot.jpg");

85:

86: if (!File.Exists(ssFile))

87: {

88: MessageBox.Show("未能找到保存的截屏图像！");

89: return;

90: }

91:

92: Process.Start(ssFile);

93: }

94:

95: private void button4_Click(object sender, EventArgs e)

96: {

97: this.Close();

98: Application.Exit();

99: }

100:

101: }

102: }

继《C#调用GoogleEarth Com API开发（一）》，我Neil又带给大家第二篇文章。这一篇文章在第一篇的基础上，展示如何调用Windows API将GoogleEarth的界面隐藏掉，并将GoogleEarth的地图显示在自定义的窗体上。废话少说，直接上代码。

1、主窗口代码：

1: // 功能：GE实例(二)

2: // 描述：GE COM API 网址：http://earth.google.com/comapi/index.html

3: // 作者：温伟鹏

4: // 日期：2009-02-08

6: using System;

7: using System.Collections.Generic;

8: using System.ComponentModel;

9: using System.Data;

10: using System.Drawing;

11: using System.Text;

12: using System.Windows.Forms;

13: using EARTHLib;

14:

15: namespace GEDemo

16: {

17: public partial class Form2 : Form

18: {

19: /// <summary>

20: /// 用来关闭GoogleEarth的消息定义

21: /// </summary>

22: static readonly Int32 WM_QUIT = 0x0012;

23:

24: private IntPtr GEHWnd = (IntPtr)5;

25: private IntPtr GEHrender = (IntPtr)5;

26: private IntPtr GEParentHrender = (IntPtr)5;

27: /// <summary>

28: /// 定义GE应用程序类

29: /// </summary>

30: private ApplicationGEClass GeApp;

31:

32: public Form2()

33: {

34: InitializeComponent();

35: }

36:

37: protected override void OnLoad(EventArgs e)

38: {

39: base.OnLoad(e);

40:

41: if (!this.DesignMode)

42: {

43: GeApp = new ApplicationGEClass();

44:

45: GEHWnd = (IntPtr)GeApp.GetMainHwnd();

46:

47: NativeMethods.SetWindowPos(GEHWnd, NativeMethods.HWND_BOTTOM, 0, 0, 0, 0,

48: NativeMethods.SWP_NOSIZE + NativeMethods.SWP_HIDEWINDOW);

49:

50: GEHrender = (IntPtr)GeApp.GetRenderHwnd();

51: GEParentHrender = (IntPtr)NativeMethods.GetParent(GEHrender);

52:

53: NativeMethods.MoveWindow(GEHrender, 0, 0, this.Width, this.Height, true);

54:

55: NativeMethods.SetParent(GEHrender, this.Handle);

56: }

57: }

58:

59: protected override void OnClosing(CancelEventArgs e)

60: {

61: base.OnClosing(e);

62:

63: NativeMethods.PostMessage(GeApp.GetMainHwnd(), WM_QUIT, 0, 0);

64: }

65: }

66: }

2、NativeMethods类定义：

1: // 功能：Windows API调用

2: // 描述：大家可以参照MSDN

3: // 作者：温伟鹏

4: // 日期：2009-02-08

6: using System;

7: using System.Collections.Generic;

8: using System.Text;

9: using System.Runtime.InteropServices;

10:

11: namespace GEDemo

12: {

13: public class NativeMethods

14: {

15: [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]

16: public static extern bool SetWindowPos(IntPtr hWnd, IntPtr hWndInsertAfter, int x, int y, int cx, int cy, UInt32 uflags);

17:

18: [DllImport("user32.dll", CharSet = CharSet.Auto)]

19: public static extern IntPtr PostMessage(int hWnd, int msg, int wParam, int lParam);

20:

21: #region 预定义

22:

23: public static readonly IntPtr HWND_BOTTOM = new IntPtr(1);

24: public static readonly IntPtr HWND_NOTOPMOST = new IntPtr(-2);

25: public static readonly IntPtr HWND_TOP = new IntPtr(0);

26: public static readonly IntPtr HWND_TOPMOST = new IntPtr(-1);

27: public static readonly UInt32 SWP_NOSIZE = 1;

28: public static readonly UInt32 SWP_NOMOVE = 2;

29: public static readonly UInt32 SWP_NOZORDER = 4;

30: public static readonly UInt32 SWP_NOREDRAW = 8;

31: public static readonly UInt32 SWP_NOACTIVATE = 16;

32: public static readonly UInt32 SWP_FRAMECHANGED = 32;

33: public static readonly UInt32 SWP_SHOWWINDOW = 64;

34: public static readonly UInt32 SWP_HIDEWINDOW = 128;

35: public static readonly UInt32 SWP_NOCOPYBITS = 256;

36: public static readonly UInt32 SWP_NOOWNERZORDER = 512;

37: public static readonly UInt32 SWP_NOSENDCHANGING = 1024;

38:

39: #endregion

40:

41: public delegate int EnumWindowsProc(IntPtr hwnd, int lParam);

42:

43: [DllImport("user32", CharSet = CharSet.Auto)]

44: public extern static IntPtr GetParent(IntPtr hWnd);

45:

46: [DllImport("user32", CharSet = CharSet.Auto)]

47: public extern static bool MoveWindow(IntPtr hWnd, int X, int Y, int nWidth, int nHeight, bool bRepaint);

48:

49: [DllImport("user32", CharSet = CharSet.Auto)]

50: public extern static IntPtr SetParent(IntPtr hWndChild, IntPtr hWndNewParent);

51:

52: [DllImport("user32.dll", ExactSpelling = true, CharSet = CharSet.Auto)]

53: public static extern IntPtr GetWindow(IntPtr hWnd, int uCmd);

54:

55: public static int GW_CHILD = 5;

56: public static int GW_HWNDNEXT = 2;

57: }

58: }

3、执行效果：