ArcGIS Engine开发之地图导出

关于地图导出的方法有很多，但是核心技术就那么一点。下面是从项目实战中总结的一部分地图导出的方法：（以全域导出和区域导出为例）

1.由于地图导出用到的函数和方法容易重复，增加了工作量故首先将其进行封装成类（ExportMap类）：用到的主要接口为：IActiveView(活动视图接口)、IGeometry(几何接口)、IRgbColor（颜色接口）、IElement（要素接口）等。

具体的封装代码如下：

   class ExportMap
     {
         #region 输出视图
         public static void ExportView(IActiveView view, IGeometry pGeo, int Outputresoultion, int Width, int Height, string ExpPath, bool bRegion)
         {
             IExport pExport = null;
             tagRECT exportrect = new tagRECT();
             IEnvelope pEnvelop = pGeo.Envelope;
             string sType = System.IO.Path.GetExtension(ExpPath);
             switch (sType)
             {
                 case ".jpg":
                     pExport = new ExportJPEGClass();
                     break;
                 case ".bmp":
                     pExport = new ExportBMPClass();
                     break;
                 case ".gif":
                     pExport = new ExportGIFClass();
                     break;
                 case ".tif":
                     pExport = new ExportTIFFClass();
                     break;
                 case ".png":
                     pExport = new ExportPNGClass();
                     break;
                 case ".pdf":
                     pExport = new ExportPDFClass();
                     break;
                 default:
                     MessageBox.Show("没有输出格式，默认JPEG");
                     pExport = new ExportJPEGClass();
                     break;
             }
             pExport.ExportFileName = ExpPath;
             exportrect.left = ;
             exportrect.top = ;
             exportrect.right = Width;
             exportrect.bottom = Height;
             if (bRegion)
             {
                 view.GraphicsContainer.DeleteAllElements();
                 view.Refresh();
             }
             IEnvelope envelop = new EnvelopeClass();
             envelop.PutCoords((double)exportrect.left, (double)exportrect.top, (double)exportrect.right, (double)exportrect.bottom);
             pExport.PixelBounds = envelop;
             view.Output(pExport.StartExporting(), Outputresoultion, ref exportrect, pEnvelop, null);
             pExport.FinishExporting();
             pExport.Cleanup();
         }
         #endregion
         #region 获取RGB颜色
         private static  IRgbColor GetRgbColor(int intR,int intG,int intB)
         {
             IRgbColor pRgbColor=null;
             if(intR<||intR>||intG<||intG>||intB<||intB>)
             {
                 return pRgbColor;
             }
             pRgbColor=new RgbColorClass();
             pRgbColor.Red=intR;
             pRgbColor.Green=intG;
             pRgbColor.Blue=intB;
             return pRgbColor;
         }
         #endregion
         #region 创建图形元素
         /// <summary>
         ///
         /// </summary>
         /// <param name="pGeomentry">几何图形</param>
         /// <param name="lineColor">边框颜色</param>
         /// <param name="fillColor">填充颜色</param>
         /// <returns></returns>
         public static IElement CreateElement(IGeometry pGeomentry, IRgbColor lineColor, IRgbColor fillColor)
         {
             if (pGeomentry == null || lineColor == null || fillColor == null)
             {
                 return null;
             }
             IElement pElem = null;
             try
             {
                 if (pGeomentry is IEnvelope)

                     pElem = new RectangleElementClass();
                 else if (pGeomentry is IPolygon)
                     pElem = new PolygonElementClass();
                 else if (pGeomentry is ICircularArc)
                 {
                     ISegment pSegCircle = pGeomentry as ISegment;
                     ISegmentCollection pSegColl = new PolygonClass();
                     object o = Type.Missing;
                     pSegColl.AddSegment(pSegCircle, ref o, ref o);
                     IPolygon pPolygon = pSegCircle as IPolygon;
                     pGeomentry = pPolygon as IGeometry;
                     pElem = new CircleElementClass();
                 }
                 else if (pGeomentry is IPolyline)
                     pElem = new LineElementClass();
                 if (pElem == null)
                     return null;
                 pElem.Geometry = pGeomentry;
                 IFillShapeElement pFElem = pElem as IFillShapeElement;
                 ISimpleFillSymbol pSymbol = new SimpleFillSymbolClass();
                 pSymbol.Color=fillColor ;
                 pSymbol.Outline.Color=lineColor;
                 pSymbol.Style = esriSimpleFillStyle.esriSFSCross;//图形元素的样式
                 if (pSymbol == null)
                 {
                     return null;
                 }
                 pFElem.Symbol = pSymbol;
             }
             catch(Exception ex)
             {
                 MessageBox.Show(ex.Message );
             }
             return pElem;
         }
         #endregion
         #region 视图窗口绘制几何图形元素
         /// <summary>
         ///
         /// </summary>
         /// <param name="pGeometry">几何图形</param>
         /// <param name="activeView">活动视图</param>
         public static void AddElement(IGeometry pGeometry,IActiveView activeView)
         {
             IRgbColor fillColor=GetRgbColor(,,);
             IRgbColor lineColor=GetRgbColor(,,);
             IElement pEle=CreateElement(pGeometry,lineColor,fillColor );//调用图形元素的函数
             IGraphicsContainer pGC = activeView.GraphicsContainer;
             if (pGC != null)
             {
                 pGC.AddElement(pEle, );
                 activeView.PartialRefresh(esriViewDrawPhase.esriViewGraphics, pEle, null);
             }
         }
         #endregion
         #region 全域导出
         /// <summary>
         /// 全域导出
         /// </summary>
         /// <param name="OutputResolution">输出分辨率</param>
         /// <param name="ExpPath">输出路径</param>
         /// <param name="view">视图</param>
         public static void ExportActiveView(int OutputResolution, string ExpPath, IActiveView view)
         {
             IExport pExport = null;
             tagRECT exportRect;
             IEnvelope envelop2 = view.Extent;
             int num = (int)Math.Round(view.ScreenDisplay.DisplayTransformation.Resolution);
             string sType = System.IO.Path.GetExtension(ExpPath);
             switch (sType)
             {
                 case ".jgp":
                     pExport = new ExportJPEGClass();
                     break;
                 case ".bmp":
                     pExport = new ExportBMPClass();
                     break;
                 case ".gif":
                     pExport = new ExportGIFClass();
                     break;
                 case ".tif":
                     pExport = new ExportTIFFClass();
                     break;
                 case ".png":
                     pExport = new ExportPNGClass();
                     break;
                 case ".pdf":
                     pExport = new ExportPDFClass();
                     break;
                 default: MessageBox.Show("No Export Foemat,the default format is JPEG!");
                     pExport = new ExportJPEGClass();
                     break;
             }
             pExport.ExportFileName = ExpPath;
             exportRect.left = ; exportRect.top = ;
             exportRect.right = (int)Math.Round((double)(view.ExportFrame.right * (((double)OutputResolution) / ((double)num))));
             exportRect.bottom = (int)Math.Round((double)(view.ExportFrame.bottom * (((double)OutputResolution) / ((double)num))));
             IEnvelope envelop = new EnvelopeClass();
             envelop.PutCoords((double)exportRect.left, (double)exportRect.top, (double)exportRect.right, (double)exportRect.bottom);
             pExport.PixelBounds = envelop;
             view.Output(pExport.StartExporting(), OutputResolution, ref exportRect, envelop2, null);
             pExport.FinishExporting();
             pExport.Cleanup();
         }
         #endregion
         #region  区域导出
         /// <summary>
         /// 区域导出
         /// </summary>
         /// <param name="pGeo">输出的图形</param>
         /// <param name="OutputResolution">输出的范围</param>
         /// <param name="ExpPath">输出路径</param>
         /// <param name="view">视图</param>
         public static void ExportRegion(IGeometry pGeo, int OutputResolution, string ExpPath, IActiveView view)
         {
             IExport export = null;
             IWorldFileSettings setting = null;
             IEnvelope envelope2 = pGeo.Envelope;
             string str = ExpPath.Substring(ExpPath.Length - , ).ToUpper();
             switch (str)
             {
                 case "JPG":
                     setting = new ExportJPEGClass();
                     export = new ExportJPEGClass();
                     setting = export as IWorldFileSettings;
                     setting.MapExtent = envelope2;
                     setting.OutputWorldFile = false;
                     break;
                 case "BMP":
                     setting = new ExportBMPClass();
                     export = new ExportBMPClass();
                     setting = export as IWorldFileSettings;
                     setting.MapExtent = envelope2;
                     setting.OutputWorldFile = false;
                     break;
                 case "TIF":
                     setting = new ExportTIFFClass();
                     export = new ExportTIFFClass();
                     setting = export as IWorldFileSettings;
                     setting.MapExtent = envelope2;
                     setting.OutputWorldFile = false;
                     break;
                 case "PNG":
                     setting = new ExportPNGClass();
                     export = new ExportPNGClass();
                     setting = export as IWorldFileSettings;
                     setting.MapExtent = envelope2;
                     setting.OutputWorldFile = false;
                     break;
                 default: break;
             }
             if (setting == null)
             {
                 export.ExportFileName = ExpPath;
                 int num = (int)Math.Round(view.ScreenDisplay.DisplayTransformation.Resolution);
                 tagRECT grect2 = new tagRECT();//实例化矩形
                 IEnvelope envelop3 = new EnvelopeClass();
                 view.ScreenDisplay.DisplayTransformation.TransformRect(envelope2, ref grect2, );
                 grect2.left = ;
                 grect2.top = ;
                 grect2.right = (int)Math.Round((double)(grect2.right - grect2.left) * (((double)OutputResolution) / ((double)num)));
                 grect2.bottom = (int)Math.Round((double)((grect2.bottom - grect2.top) * (((double)OutputResolution) / ((double)num))));
                 envelop3.PutCoords((double)grect2.left, (double)grect2.top, (double)grect2.right, (double)grect2.bottom);
                 export.PixelBounds = envelop3;
                 view.GraphicsContainer.DeleteAllElements();
                 view.Output(export.StartExporting(), OutputResolution, ref grect2, envelope2, null);
                 export.FinishExporting();
                 export.Cleanup();
                 AddElement(pGeo, view);
             }

         }
         #endregion
     }

2.添加输出设置窗体，分别有，输出图片的高、宽、分辨率、输出保存路径、导出按钮。

具体的设置代码如下：

 public partial class ExportMapForm : DevExpress.XtraEditors.XtraForm
     {
         //定义全局变量
         private string pSavePath = "";
         private IActiveView pActiveView;
         private IGeometry pGeometry = null;
         #region 只读属性，地图导出空间图形
         public IGeometry GetGeometry
         {
             set { pGeometry = value; }
         }
         private bool bRegion = true;
         #endregion
         /// <summary>
         /// 只读属性，是全域导出还是区域导出
         /// </summary>
         public bool IsRegion
         {
             set { bRegion = value; }
         }

         //获取主窗口的MapControl控件
         public ExportMapForm(AxMapControl mainAxMapControl)
         {
             InitializeComponent();

             pActiveView = mainAxMapControl.ActiveView;

         }

         private void ExportMapForm_Load(object sender, EventArgs e)
         {

         }
         #region 输入窗口的大小
         private void InitFormSize()
         {
             cboResoultion.Text = pActiveView.ScreenDisplay.DisplayTransformation.Resolution.ToString();
             cboResoultion.Items.Add(cboResoultion.Text);
             if (bRegion)
             {
                 IEnvelope pEnvelop = pGeometry.Envelope;
                 tagRECT pRECT = new tagRECT();
                 pActiveView.ScreenDisplay.DisplayTransformation.TransformRect(pEnvelop, ref pRECT,);
                 if (cboResoultion.Text != "")
                 {
                     txtWidth.Text = pRECT.right.ToString();
                     txtHeight.Text = pRECT.bottom.ToString();
                 }
             }
             else
             {
                 if (cboResoultion.Text != "")
                 {
                     txtWidth.Text = pActiveView.ExportFrame.right.ToString();
                     txtHeight.Text = pActiveView.ExportFrame.bottom.ToString();
                 }
             }
         }
         #endregion
         #region combox的ChangeIndex事件
         private void cboResoultion_SelectedIndexChanged(object sender, EventArgs e)
         {
             double num = (int)Math.Round(pActiveView.ScreenDisplay.DisplayTransformation.Resolution);
             if (cboResoultion.Text == "")
             {
                 txtWidth.Text = "";
                 txtHeight.Text = "";
                 return;
             }
             if (bRegion)
             {
                 IEnvelope pEnvelop = pGeometry.Envelope;
                 tagRECT pRECT = new tagRECT();
                 pActiveView.ScreenDisplay.DisplayTransformation.TransformRect(pEnvelop, ref pRECT,);
                 if (cboResoultion.Text != "")
                 {
                     txtWidth.Text = Math.Round((double)(pRECT.right * (double.Parse(cboResoultion.Text) / (double)num))).ToString();
                 }
             }
             else
             {
                 txtWidth.Text = Math.Round((double)(pActiveView.ExportFrame.right * (double.Parse(cboResoultion.Text) / (double)num))).ToString();
                 txtHeight.Text = Math.Round((double)(pActiveView.ExportFrame.bottom * (double.Parse(cboResoultion.Text) / (double)num))).ToString();
             }
         }
         #endregion
         #region 保存按钮的单击事件
         private void btnExPath_Click(object sender, EventArgs e)
         {
             SaveFileDialog sfdExportMap = new SaveFileDialog();
             sfdExportMap.DefaultExt = "jpg|bmp|gif|tif|png|pdf";
             sfdExportMap.Filter = "JPGE 文件(*.jpg)|*.jpg|BMP 文件(*.bmp)|*.bmp|GIF 文件(*.gif)|*.gif|TIF 文件(*.tif)|*.tif|PNG 文件(*.png)|*.png|PDF 文件(*.pdf)|*.pdf";
             sfdExportMap.OverwritePrompt = true;//重复写入时提示错误
             sfdExportMap.Title = "保存为";
             txtExPath.Text = "";
             if (sfdExportMap.ShowDialog() != DialogResult.Cancel)
             {
                 pSavePath = sfdExportMap.FileName;
                 txtExPath.Text = sfdExportMap.FileName;
             }
         }
         #endregion
         #region 导出按钮单击事件
         private void btnExPort_Click(object sender, EventArgs e)
         {
             if (txtExPath.Text == "")
             {
                 MessageBox.Show("请先确定导出路径！", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
                 return;
             }
             else if (cboResoultion.Text == "")
             {
                 if (txtExPath.Text == "")
                 {
                     MessageBox.Show("请输入分辨率！", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
                     return;
                 }
             }
             else if (Convert.ToInt16(cboResoultion.Text) == )
             {
                 MessageBox.Show("请正确输入分辨率！", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
                 return;
             }
             else
             {
                 try
                 {
                     int resoultion = int.Parse(cboResoultion.Text);//输出图片的分辨率
                     int width = int.Parse(cboResoultion.Text);//输出图片的宽度
                     int height = int.Parse(cboResoultion.Text);//输出图片的高度
                     ExportMap.ExportView(pActiveView, pGeometry, resoultion, width, height, pSavePath, bRegion);
                     pActiveView.GraphicsContainer.DeleteAllElements();
                     pActiveView.Refresh();
                     MessageBox.Show("导出成功！", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
                 }
                 catch (Exception)
                 {
                     MessageBox.Show("导出失败！", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
                 }
             }
         }
         #endregion
         #region 取消按钮的单击事件
         private void btnCancel_Click(object sender, EventArgs e)
         {
             //局部导出时没有导出图像就退出
             pActiveView.GraphicsContainer.DeleteAllElements();
             pActiveView.Refresh();
             Dispose();
         }
         #endregion
         #region 图片导出窗口Close事件
         private void ExportMapForm_FormClosed(object sender, FormClosedEventArgs e)
         {
             //局部导出时没有导出图像就关闭
             pActiveView.GraphicsContainer.DeleteAllElements();
             pActiveView.Refresh();
             Dispose();

         }
         #endregion

3.在main窗体中进行实例化输出窗体：private ExportMapForm frmExpMap = null;

4.在MainMap Control_OnMouseDown中进行写入case：（只适合区域导出，单击选择边框）

 #region 地图的区域导出
                     case "ExportRegion":
                         //删除视图中的数据
                         mainMapControl.ActiveView.GraphicsContainer.DeleteAllElements();
                         mainMapControl.ActiveView.Refresh();
                         IPolygon pPolygon = DrawPolygon(mainMapControl);
                         if (pPolygon == null) return;
                         ExportMap.AddElement(pPolygon, mainMapControl.ActiveView);
                         if (frmExpMap == null || frmExpMap.IsDisposed)
                         {
                             frmExpMap = new ExportMapForm(mainMapControl);
                         }
                         frmExpMap.IsRegion = true;
                         frmExpMap.GetGeometry = pPolygon as IGeometry;
                         frmExpMap.Show();
                         frmExpMap.Activate();
                         break;
                     #endregion

5.全域导出和区域导出按钮的单击事件代码：

       #region 地图导出之全域导出
         private void btnExportMap_ItemClick(object sender, ItemClickEventArgs e)
         {
             if (frmExpMap == null || frmExpMap.IsDisposed)
             {
                 frmExpMap = new ExportMapForm(mainMapControl);
             }
             frmExpMap.IsRegion = false;
             frmExpMap.GetGeometry = mainMapControl.ActiveView.Extent;
             frmExpMap.Show();
             frmExpMap.Activate();
         }
         #endregion
         #region 地图导出之区域导出
         private void btnExportRegionMap_ItemClick(object sender, ItemClickEventArgs e)
         {
             mainMapControl.CurrentTool = null;
             mainMapControl.MousePointer = esriControlsMousePointer.esriPointerCrosshair;
             pMouseOperate = "ExportRegion";
         }
         #endregion