C# 调用 Google Earth Com API开发（三）

好久没有更新《C#调用Google Earth Com API开发》系列文章了，今天带给大家的是第三篇，本篇相对于第二篇主要改进了三个方面。

1) 实现GoogleEarth显示画面随窗口大小改变而改变

2) 截获GoogleEarth鼠标消息，实现单击、双击功能；鼠标滚轮缩放现在只能放大！O(∩_∩)O~

3) 实现GoogleEarth彩色截图（测试环境：Windows 2003 Server ，Vista与Win7中不可用，XP未测）

下面还是继续看代码：

1、GoogleEarth动态改变大小

   1: /// <summary>

   2: /// 重新改变GoogleEarth视图的大小

   3: /// </summary>

   4: private void ResizeGoogleControl()

   5: {

   6:     NativeMethods.SendMessage(GEHWnd, (uint)NativeMethods.WM_COMMAND, NativeMethods.WM_PAINT, 0);

   7:     NativeMethods.PostMessage(GEHWnd, NativeMethods.WM_QT_PAINT, 0, 0);

   8:  

   9:     RECT mainRect = new RECT();

  10:     NativeMethods.GetWindowRect(GEHWnd, out mainRect);

  11:     clientRect = new RECT();

  12:     NativeMethods.GetClientRect(GEHrender, out clientRect);

  13:  

  14:     int offsetW = mainRect.Width - clientRect.Width;

  15:     int offsetH = mainRect.Height - clientRect.Height;

  16:  

  17:     int newWidth = this.Control.Width + (int)offsetW;

  18:     int newHeight = this.Control.Height + (int)offsetH;

  19:  

  20:     NativeMethods.SetWindowPos(GEHWnd, NativeMethods.HWND_TOP,

  21:         0, 0, newWidth, newHeight, 

  22:         NativeMethods.SWP_FRAMECHANGED);

  23:  

  24:     NativeMethods.SendMessage(GEHWnd, (uint)NativeMethods.WM_COMMAND, NativeMethods.WM_SIZE, 0);

  25: }

2、鼠标消息

此例子中对于鼠标消息到处理使用了钩子，调用HookAPI.dll实现。

   1:          /// <summary>

   2:          /// 鼠标钩子

   3:          /// </summary>

   4:          private MouseHook mouseHook;

   5:   

   6:          // 设置鼠标钩子

   7:          mouseHook = new MouseHook();

   8:          mouseHook.MouseClick += new MouseEventHandler(mouseHook_MouseClick);

   9:          mouseHook.MouseDbClick += new MouseEventHandler(mouseHook_MouseDbClick);

  10:          mouseHook.MouseWheel += new MouseEventHandler(mouseHook_MouseWheel);

  11:         // 启动鼠标钩子

  12:          mouseHook.StartHook(HookType.WH_MOUSE_LL, 0);

单击事件：

   1: /// <summary>

   2: /// 鼠标钩子。鼠标单击事件

   3: /// </summary>

   4: /// <param name="sender"></param>

   5: /// <param name="e"></param>

   6: void mouseHook_MouseClick(object sender, MouseEventArgs e)

   7: {

   8:     IntPtr hWnd = NativeMethods.WindowFromPoint(e.Location);

   9:     if (hWnd == this.GeRenderHWnd)

  10:     {

  11:         Point point = this.Control.PointToClient(e.Location);

  12:         // 如果鼠标击点位置在控件内部，则说明鼠标点击了GoogleEarth视图

  13:         if (this.Control.ClientRectangle.Contains(point))

  14:         {

  15:             Console.WriteLine("点击了GoogleEarth...");

  16:  

  17:             DoublePoint dp = ((GERenderPanel)Control).DetermineScreenCoordinates(point.X, point.Y);

  18:  

  19:             ParameterizedThreadStart pts = new ParameterizedThreadStart(ShowMouseClickPoint);

  20:  

  21:             Thread thread = new Thread(pts);

  22:             thread.Start(dp);

  23:  

  24:         }

  25:     }

  26: }

  27:  

  28: protected void ShowMouseClickPoint(object obj)

  29: {

  30:     //Thread.Sleep(20);

  31:     DoublePoint dp = (DoublePoint)obj;

  32:     PointOnTerrainGE pGe = GeApp.GetPointOnTerrainFromScreenCoords(dp.X, dp.Y);

  33:     Console.WriteLine("鼠标点击了：Lnt=" + pGe.Longitude.ToString() 

  34:         + ";Lat=" + pGe.Latitude.ToString());

  35: }

 

双击事件：

   1: /// <summary>

   2:  /// 鼠标钩子。鼠标双击事件

   3:  /// </summary>

   4:  /// <param name="sender"></param>

   5:  /// <param name="e"></param>

   6:  void mouseHook_MouseDbClick(object sender, MouseEventArgs e)

   7:  {

   8:      IntPtr hWnd = NativeMethods.WindowFromPoint(e.Location);

   9:      if (hWnd == this.GeRenderHWnd)

  10:      {

  11:          Point point = this.Control.PointToClient(e.Location);

  12:          // 如果鼠标击点位置在控件内部，则说明鼠标点击了GoogleEarth视图

  13:          if (this.Control.ClientRectangle.Contains(point))

  14:          {

  15:              Console.WriteLine("xx双击了GoogleEarth...");

  16:  

  17:              DoublePoint dp = ((GERenderPanel)Control).DetermineScreenCoordinates(point.X, point.Y);

  18:  

  19:              ParameterizedThreadStart pts = new ParameterizedThreadStart(ShowMouseDbClickPoint);

  20:  

  21:              Thread thread = new Thread(pts);

  22:              thread.Start(dp);

  23:  

  24:          }

  25:      }

  26:  }

  27:  

  28:  protected void ShowMouseDbClickPoint(object obj)

  29:  {

  30:      //Thread.Sleep(20);

  31:      DoublePoint dp = (DoublePoint)obj;

  32:      PointOnTerrainGE pGe = GeApp.GetPointOnTerrainFromScreenCoords(dp.X, dp.Y);

  33:      Console.WriteLine("xx鼠标双击了：Lnt=" + pGe.Longitude.ToString()

  34:          + ";Lat=" + pGe.Latitude.ToString());

  35:  

  36:      MessageBox.Show("我还是出来一下吧！省得你不知道你已经双击了鼠标！");

  37:  }

 

这两处代码还比较简陋，比如未添加主窗口焦点检测，相信读者可以自行添加。O(∩_∩)O~

3、截图

程序中有两种截图功能，一种是GoogleEarth自带的截图功能，只能截取黑白图片；另一种为彩色截图，但是Vista以上操作系统不支持，还未找到合适的方法实现Vista与Win7兼容。

1) GoogleEarth自带截图功能：

   1: GEViewContent view = GetGEView();

   2:  

   3: if (view != null)

   4: {

   5:     ApplicationGE ge = view.GeApplication;

   6:     if (ge != null && ge.IsInitialized() > 0)

   7:     {

   8:         using (SaveFileDialog sfd = new SaveFileDialog())

   9:         {

  10:             sfd.Filter = "jpg图片|*.jpg";

  11:             sfd.AddExtension = true;

  12:             sfd.CheckPathExists = true;

  13:             sfd.Title = "保存Google Earth截图";

  14:  

  15:             if (sfd.ShowDialog() == DialogResult.OK)

  16:             {

  17:                 ge.SaveScreenShot(sfd.FileName, 100);

  18:             }

  19:         }

  20:     }

  21: }

2) 彩色截图：

   1: GEViewContent view = GetGEView();

   2: if (view != null)

   3: {

   4:     int nWidth = view.Control.Width;

   5:     int nHeight = view.Control.Height;

   6:     Point pt = view.Control.PointToScreen(view.Control.Location);

   7:     int nXSrc = pt.X;

   8:     int nYSrc = pt.Y;

   9:  

  10:     IntPtr hRender = view.GeRenderHWnd;

  11:  

  12:     if (hRender != IntPtr.Zero)

  13:     {

  14:         // 取得Render DC

  15:         IntPtr hRenderDC = NativeMethods.GetWindowDC(hRender);

  16:         // 创建hBitmap

  17:         IntPtr hBitmap = NativeMethods.CreateCompatibleBitmap(hRenderDC, nWidth, nHeight);

  18:         // 创建MEM DC

  19:         IntPtr hMemDC = NativeMethods.CreateCompatibleDC(hRenderDC);

  20:         // 将Bitmap Select到MemDC

  21:         NativeMethods.SelectObject(hMemDC, hBitmap);

  22:         // 直接拷屏

  23:         NativeMethods.BitBlt(hMemDC, 0, 0, nWidth, nHeight,

  24:             hRenderDC, 0, 0, 13369376);

  25:  

  26:         using(Bitmap bmp = Bitmap.FromHbitmap(hBitmap))

  27:         {

  28:             using(SaveFileDialog sfd = new SaveFileDialog())

  29:             {

  30:                 sfd.Filter = "JPG图片|*.jpg|PNG图片|*.png";

  31:                 sfd.AddExtension = true;

  32:                 sfd.CheckPathExists = true;

  33:                 sfd.Title = "保存Google Earth截图";

  34:  

  35:                 if (sfd.ShowDialog() == DialogResult.OK)

  36:                 {

  37:                     ImageFormat imgFormat = null;

  38:                     // 默认选择JPG

  39:                     if (sfd.FilterIndex == 0)

  40:                     {

  41:                         imgFormat = ImageFormat.Jpeg;

  42:                     }

  43:                     // 选择PNG

  44:                     else

  45:                     {

  46:                         imgFormat = ImageFormat.Png;

  47:                     }

  48:                     bmp.Save(sfd.FileName, imgFormat);

  49:                 }

  50:             }

  51:             

  52:             //销毁资源

  53:             NativeMethods.DeleteDC(hRenderDC);

  54:             NativeMethods.DeleteDC(hMemDC);

  55:         }

  56:     }

 

OK，这篇GE开发到此为止，请读者继续等待后面的精彩文章…

不好意思，刚才忘记上传源程序了！

https://files.cnblogs.com/wpwen/GEDemo_2009-05-22.rar