C#调用GoogleEarthComAPI开发（三）(转载)

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原作者: [db:作者] 来自: [db:来源] 收藏邀请

原文地址：http://www.cnblogs.com/wpwen/archive/2009/05/22/1486892.html

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

/// <summary>

/// 重新改变GoogleEarth视图的大小

/// </summary>

void ResizeGoogleControl()

   5: {

uint)NativeMethods.WM_COMMAND, NativeMethods.WM_PAINT, 0);

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

   8:  

new RECT();

out mainRect);

new RECT();

out clientRect);

  13:  

int offsetW = mainRect.Width - clientRect.Width;

int offsetH = mainRect.Height - clientRect.Height;

  16:  

int)offsetW;

int)offsetH;

  19:  

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

  21:         0, 0, newWidth, newHeight, 

  22:         NativeMethods.SWP_FRAMECHANGED);

  23:  

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：

/// <summary>

/// 鼠标钩子。鼠标单击事件

/// </summary>

object sender, MouseEventArgs e)

   7: {

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

this.GeRenderHWnd)

  10:     {

this.Control.PointToClient(e.Location);

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

this.Control.ClientRectangle.Contains(point))

  14:         {

);

  16:  

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

  18:  

new ParameterizedThreadStart(ShowMouseClickPoint);

  20:  

new Thread(pts);

  22:             thread.Start(dp);

  23:  

  24:         }

  25:     }

  26: }

  27:  

object obj)

  29: {

//Thread.Sleep(20);

  31:     DoublePoint dp = (DoublePoint)obj;

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

 + pGe.Longitude.ToString() 

 + pGe.Latitude.ToString());

  35: }

双击事件：

/// <summary>

/// 鼠标钩子。鼠标双击事件

/// </summary>

object sender, MouseEventArgs e)

   7:  {

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

this.GeRenderHWnd)

  10:      {

this.Control.PointToClient(e.Location);

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

this.Control.ClientRectangle.Contains(point))

  14:          {

);

  16:  

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

  18:  

new ParameterizedThreadStart(ShowMouseDbClickPoint);

  20:  

new Thread(pts);

  22:              thread.Start(dp);

  23:  

  24:          }

  25:      }

  26:  }

  27:  

object obj)

  29:  {

//Thread.Sleep(20);

  31:      DoublePoint dp = (DoublePoint)obj;

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

 + pGe.Longitude.ToString()

 + pGe.Latitude.ToString());

  35:  

);

  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:  

null)

   4: {

   5:     ApplicationGE ge = view.GeApplication;

null && ge.IsInitialized() > 0)

   7:     {

new SaveFileDialog())

   9:         {

;

true;

true;

;

  14:  

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();

null)

   3: {

int nWidth = view.Control.Width;

int nHeight = view.Control.Height;

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

int nXSrc = pt.X;

int nYSrc = pt.Y;

   9:  

  10:     IntPtr hRender = view.GeRenderHWnd;

  11:  

if (hRender != IntPtr.Zero)

  13:     {

// 取得Render DC

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

// 创建hBitmap

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

// 创建MEM DC

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

// 将Bitmap Select到MemDC

  21:         NativeMethods.SelectObject(hMemDC, hBitmap);

// 直接拷屏

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

  24:             hRenderDC, 0, 0, 13369376);

  25:  

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

  27:         {

new SaveFileDialog())

  29:             {

;

true;

true;

;

  34:  

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

  36:                 {

null;

// 默认选择JPG

if (sfd.FilterIndex == 0)

  40:                     {

  41:                         imgFormat = ImageFormat.Jpeg;

  42:                     }

// 选择PNG

else

  45:                     {

  46:                         imgFormat = ImageFormat.Png;

  47:                     }

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

  49:                 }

  50:             }

  51:             

//销毁资源

  53:             NativeMethods.DeleteDC(hRenderDC);

  54:             NativeMethods.DeleteDC(hMemDC);

  55:         }

  56:     }