C#+AE 地图制图(一)

待我称王封你为后i 2023-02-12 05:26 9阅读 0赞

### 文章目录 ###

*  一、地图制图
 *   *  1.1颜色模型
     *  1.2专题制图
 *  二、部分功能实现
 *   *  2.1视图同步
     *  2.2图例、指北针和比例尺
 *  三、小结

# 一、地图制图 #

> 地图制图是研究地图及其编制和应用的一门学科，它研究用地图反映自然界和人类社会各种线性的空间分布、相互联系及其动态变化的规律。地图制图的核心内容其实就是地图符号的运用，它通过色彩和图形等的不同组合来描述地理现象和解释地理规律。

在没有了解ArcgisEngine中的地图制图之前，我总感觉这部分应该会很简单，添加个指北针、图例啥的不就行了吗，但是真正了解之后是真的心累啊，这部分的内容是比较繁杂的，许多概念都需要搞清楚弄明白才能较好的掌握这部分内容。

## 1.1颜色模型 ##

> 1、RGB模型：也称加色法模型，它是以红、绿、蓝为三原色，将各种原色混合在一起即可产生复合色，适用于显示器等发光体的显示。  
> 2、CMYK模型：这种模型是专门针对印刷业设定的彩色标准，它通过对青©、品红(M)、黄(Y)、黑(K)这四种颜色的变化以及他们相互之间的叠加来得到各种颜色。相较于RGB模式，CMYK模式是一种依靠反光的色彩模式。  
> 3、HSV模型：该模型是根据颜色的直观特性而创建的一种颜色空间，也称为六角锥体模型。模型中的参数分别是：色调(H)、饱和度(S)和亮度(V)。H用于角度度量，取值范围为0-360，从红色开始按逆时针方向计算，红色为0，绿色为120，蓝色为240，他们的补色是黄色60、青色180、品红300；S表示颜色的纯度；V表示颜色的明暗值，描述颜色的明暗度，取值0-100。该模型是一种比较直观的颜色模型，在图像编辑工具中被广泛应用，但是其不能直接进行光线混合运算和光强运算等操作。  
> Gray模型：也称灰色模型，也就是我们常说的黑白图像。

## 1.2专题制图 ##

> 专题地图是着重表示一种或几种自然或社会经济现象的地理分布或强调这些现象的某一方面特征的地图。专题地图通常使用数据集的一组或多组数据，利用颜色渲染、图案填充、符号、图标等方法，给数据中的特定值指派特定的颜色、图案或符号，从而创建不同的专题地图。

本次的学习因为也只学习了地图制图的一部分，所以就写了这几个概念\*~\*。

# 二、部分功能实现 #

## 2.1视图同步 ##

有时候不免要进行MapControl控件与PageLayoutControl控件的切换，此时就需要进行视图同步了。  
代码如下:

/// <summary>
            /// 视图同步
            /// </summary>
            public void copyToPageLayout()
            { 
                IObjectCopy objectCopy = new ObjectCopy();//对象拷贝接口
                object copyFromMap = axMapControl_MapView.Map;//地图对象
                object copyMap = objectCopy.Copy(copyFromMap);//将axMapControl1的地图对象拷贝
                object copyToMap = axPageLayoutControl.ActiveView.FocusMap;//axPageLayoutControl活动视图中的地图
                objectCopy.Overwrite(copyMap, ref copyToMap);//将axMapControl地图对象覆盖axPageLayout当前地图
            }
    
    		//OnMapReplaced事件是指一个地图被另一个地图替换时会触发该事件
            private void axMapControl_MapView_OnMapReplaced(object sender, AxESRI.ArcGIS.Controls.IMapControlEvents2_OnMapReplacedEvent e)
            { 
                copyToPageLayout();
            }
    		
    		//地图绘制完成后会触发该事件
            private void axMapControl_MapView_OnAfterScreenDraw(object sender, AxESRI.ArcGIS.Controls.IMapControlEvents2_OnAfterScreenDrawEvent e)
            { 
                IActiveView activeView = (IActiveView)axPageLayoutControl.ActiveView.FocusMap;//axPageLayoutControl的活动视图的地图
                IDisplayTransformation displayTransformation = activeView.ScreenDisplay.DisplayTransformation;//活动视图的屏幕显示的显示信息
                displayTransformation.VisibleBounds = axMapControl_MapView.Extent;//将axMapControl的范围赋值给axPageLayoutControl的范围
                axPageLayoutControl.ActiveView.Refresh();//刷新axPageLayoutControl的活动视图
                copyToPageLayout();//将axMapControl的地图拷贝到axPageLayoutControl中
            }

实现效果：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2RheXVoYWl0YW5nMQ_size_16_color_FFFFFF_t_70]

## 2.2图例、指北针和比例尺 ##

代码如下：  
mainForm.cs:

//全局变量
    		private OperatePageLayout m_OperatePageLayout = null;
            private INewEnvelopeFeedback pNewEnvelopeFeedback;	//控制包络创建的对象
            private IPoint m_MovePt = null;
            private IPoint m_PointPt = null;
            private EnumMapSurroundType _enumMapSurType = EnumMapSurroundType.None;
            private FrmSymbol frmSym = null;
            private IStyleGalleryItem pStyleGalleryItem;
    
            
    		//axPageLayoutControl控件的点击事件
     		private void axPageLayoutControl_OnMouseDown(object sender, AxESRI.ArcGIS.Controls.IPageLayoutControlEvents_OnMouseDownEvent e)
            { 
                if (_enumMapSurType != EnumMapSurroundType.None)
                { 
                    IActiveView pActiveView = null;
                    pActiveView = axPageLayoutControl.PageLayout as IActiveView;
                    m_PointPt = pActiveView.ScreenDisplay.DisplayTransformation.ToMapPoint(e.x, e.y);
                    if (pNewEnvelopeFeedback == null)
                    { 
                        pNewEnvelopeFeedback = new NewEnvelopeFeedbackClass();
                        pNewEnvelopeFeedback.Display = pActiveView.ScreenDisplay;
                        pNewEnvelopeFeedback.Start(m_PointPt);
                    }
                    else
                    { 
                        pNewEnvelopeFeedback.MoveTo(m_PointPt);
                    }
                }
            }
    		
    		//鼠标移动事件
    		private void axPageLayoutControl_OnMouseMove(object sender, AxESRI.ArcGIS.Controls.IPageLayoutControlEvents_OnMouseMoveEvent e)
            { 
                try
                { 
                    if (_enumMapSurType != EnumMapSurroundType.None)
                    { 
                        if (pNewEnvelopeFeedback != null)
                        { 
                            m_MovePt = (axPageLayoutControl.PageLayout as IActiveView).ScreenDisplay.DisplayTransformation.ToMapPoint(e.x, e.y);
                            pNewEnvelopeFeedback.MoveTo(m_MovePt);
                        }
                    }
                }
                catch
                { 	}
            }
    
    		//鼠标弹起事件
    		private void axPageLayoutControl_OnMouseUp(object sender, AxESRI.ArcGIS.Controls.IPageLayoutControlEvents_OnMouseUpEvent e)
            { 
                if (_enumMapSurType != EnumMapSurroundType.None)
                { 
                    if (pNewEnvelopeFeedback != null)
                    { 
                        IActiveView pActiveView = null;
                        pActiveView = axPageLayoutControl.PageLayout as IActiveView;
                        IEnvelope pEnvelope = pNewEnvelopeFeedback.Stop();
                        AddMapSurround(pActiveView, _enumMapSurType, pEnvelope);
                        pNewEnvelopeFeedback = null;
                        _enumMapSurType = EnumMapSurroundType.None;
                    }
                }
            }
            
            //图例
            private void barButtonItem_legend_ItemClick(object sender, DevExpress.XtraBars.ItemClickEventArgs e)
            { 
                try
                { 
                    _enumMapSurType = EnumMapSurroundType.Legend;
                }
                catch 
                { 	}
            }
    
    		//指北针
    		private void barButtonItem_NorthArrow_ItemClick(object sender, DevExpress.XtraBars.ItemClickEventArgs e)
            { 
                try
                { 
                    _enumMapSurType = EnumMapSurroundType.NorthArrow;
                    if (frmSym == null || frmSym.IsDisposed)
                    { 
                        frmSym = new FrmSymbol();
                        frmSym.GetSelSymbolItem += new FrmSymbol.GetSelSymbolItemEventHandler(frmSym_GetSelSymbolItem);	//绑定获取符号样式的事件
                    }
                    frmSym.EnumMapSurType = _enumMapSurType;
                    frmSym.InitUI();
                    frmSym.ShowDialog();
                }
                catch (Exception ex)
                { 
                    MessageBox.Show(ex.Message);
                }
            }
    
    		//获取符号样式
    		private void frmSym_GetSelSymbolItem(ref IStyleGalleryItem pStyleItem)
            { 
                pStyleGalleryItem = pStyleItem;
            }
    
    		//比例尺
    		private void barButtonItem_Scale_ItemClick(object sender, DevExpress.XtraBars.ItemClickEventArgs e)
            { 
                try
                { 
                    _enumMapSurType = EnumMapSurroundType.ScaleBar;
                    if (frmSym == null || frmSym.IsDisposed)
                    { 
                        frmSym = new FrmSymbol();
                        frmSym.GetSelSymbolItem += new FrmSymbol.GetSelSymbolItemEventHandler(frmSym_GetSelSymbolItem);	//绑定获取符号样式的事件
                    }
                    frmSym.EnumMapSurType = _enumMapSurType;
                    frmSym.InitUI();
                    frmSym.ShowDialog();
                }
                catch (Exception ex)
                { 	}
            }
    
    		// 添加整饰的要素
    		 private void AddMapSurround(IActiveView pAV, EnumMapSurroundType _enumMapSurroundType, IEnvelope pEnvelope)
            { 
                try
                { 
                    switch (_enumMapSurroundType)
                    { 
                        case EnumMapSurroundType.NorthArrow:
                            addNorthArrow(axPageLayoutControl.PageLayout, pEnvelope, pAV);
                            break;
                        case EnumMapSurroundType.ScaleBar:
                            makeScaleBar(pAV, axPageLayoutControl.PageLayout, pEnvelope);
                            break;
                        case EnumMapSurroundType.Legend:
                            MakeLegend(pAV, axPageLayoutControl.PageLayout, pEnvelope);
                            break;
                    }
                }
                catch (Exception ex)
                { 
                    MessageBox.Show(ex.Message);
                }
            }
    
    		// 添加图例
    		private void MakeLegend(IActiveView pActiveView, IPageLayout pPageLayout, IEnvelope pEnv)
            { 
                UID pID = new UID();
                pID.Value = "esriCarto.Legend";
                IGraphicsContainer pGraphicsContainer = pPageLayout as IGraphicsContainer;
                IMapFrame pMapFrame = pGraphicsContainer.FindFrame(pActiveView.FocusMap) as IMapFrame;
                IMapSurroundFrame pMapSurroundFrame = pMapFrame.CreateSurroundFrame(pID, null);//根据唯一标示符，创建与之对应MapSurroundFrame
                IElement pDeletElement = axPageLayoutControl.FindElementByName("Legend");//获取PageLayout中的图例元素
                if (pDeletElement != null)
                { 
                    pGraphicsContainer.DeleteElement(pDeletElement);  //如果已经存在图例，删除已经存在的图例
                }
                //设置MapSurroundFrame背景
                ISymbolBackground pSymbolBackground = new SymbolBackgroundClass();
                IFillSymbol pFillSymbol = new SimpleFillSymbolClass();
                ILineSymbol pLineSymbol = new SimpleLineSymbolClass();
                pLineSymbol.Color = m_OperatePageLayout.GetRgbColor(0, 0, 0);
                pFillSymbol.Color = m_OperatePageLayout.GetRgbColor(240, 240, 240);
                pFillSymbol.Outline = pLineSymbol;
                pSymbolBackground.FillSymbol = pFillSymbol;
                pMapSurroundFrame.Background = pSymbolBackground;
                //添加图例
                IElement pElement = pMapSurroundFrame as IElement;
                pElement.Geometry = pEnv as IGeometry;
                IMapSurround pMapSurround = pMapSurroundFrame.MapSurround;
                ILegend pLegend = pMapSurround as ILegend;
                pLegend.ClearItems();
                pLegend.Title = "图例";
                for (int i = 0; i < pActiveView.FocusMap.LayerCount; i++)
                { 
                    ILegendItem pLegendItem = new HorizontalLegendItemClass();
                    pLegendItem.Layer = pActiveView.FocusMap.get_Layer(i);//获取添加图例关联图层 
                    pLegendItem.ShowDescriptions = false;
                    pLegendItem.Columns = 1;
                    pLegendItem.ShowHeading = true;
                    pLegendItem.ShowLabels = true;
                    pLegend.AddItem(pLegendItem);//添加图例内容
                }
                pGraphicsContainer.AddElement(pElement, 0);
                pActiveView.PartialRefresh(esriViewDrawPhase.esriViewGraphics, null, null);
            }
    
    		//添加指北针
    		void addNorthArrow(IPageLayout pPageLayout, IEnvelope pEnv, IActiveView pActiveView)
            { 
                IMap pMap = pActiveView.FocusMap;
                IGraphicsContainer pGraphicsContainer = pPageLayout as IGraphicsContainer;
                IMapFrame pMapFrame = pGraphicsContainer.FindFrame(pMap) as IMapFrame;
                if (pStyleGalleryItem == null) return;
                IMapSurroundFrame pMapSurroundFrame = new MapSurroundFrameClass();
                pMapSurroundFrame.MapFrame = pMapFrame;
                INorthArrow pNorthArrow = new MarkerNorthArrowClass();
                pNorthArrow = pStyleGalleryItem.Item as INorthArrow;
                pNorthArrow.Size = pEnv.Width * 50;
                pMapSurroundFrame.MapSurround = (IMapSurround)pNorthArrow;//根据用户的选取，获取相应的MapSurround 
                IElement pElement = axPageLayoutControl.FindElementByName("NorthArrows");//获取PageLayout中的指北针元素
                if (pElement != null)
                { 
                    pGraphicsContainer.DeleteElement(pElement);  //如果存在指北针，删除已经存在的指北针
                }
                IElementProperties pElePro = null;
                pElement = (IElement)pMapSurroundFrame;
                pElement.Geometry = (IGeometry)pEnv;
                pElePro = pElement as IElementProperties;
                pElePro.Name = "NorthArrows";
                pGraphicsContainer.AddElement(pElement, 0);
                pActiveView.PartialRefresh(esriViewDrawPhase.esriViewGraphics, null, null);
            }
    
    		//添加比例尺
    		 public void makeScaleBar(IActiveView pActiveView, IPageLayout pPageLayout, IEnvelope pEnv)
            { 
                IMap pMap = pActiveView.FocusMap;
                IGraphicsContainer pGraphicsContainer = pPageLayout as IGraphicsContainer;
                IMapFrame pMapFrame = pGraphicsContainer.FindFrame(pMap) as IMapFrame;
                if (pStyleGalleryItem == null) return;
                IMapSurroundFrame pMapSurroundFrame = new MapSurroundFrameClass();
                pMapSurroundFrame.MapFrame = pMapFrame;
                pMapSurroundFrame.MapSurround = (IMapSurround)pStyleGalleryItem.Item;
                IElement pElement = axPageLayoutControl.FindElementByName("ScaleBar");
                if (pElement != null)
                { 
                    pGraphicsContainer.DeleteElement(pElement);  //删除已经存在的比例尺
                }
                IElementProperties pElePro = null;
                pElement = (IElement)pMapSurroundFrame;
                pElement.Geometry = (IGeometry)pEnv;
                pElePro = pElement as IElementProperties;
                pElePro.Name = "ScaleBar";
                pGraphicsContainer.AddElement(pElement, 0);
                pActiveView.PartialRefresh(esriViewDrawPhase.esriViewGraphics, null, null);
            }

EnumMapSurroundType.cs:

//创建要素枚举类型
    	public enum EnumMapSurroundType
        { 
            None = 0,
            NorthArrow = 1,
            ScaleBar = 2,
            Legend = 3,
        }

FrmSymbol.cs:

public partial class FrmSymbol : DevExpress.XtraEditors.XtraForm
        { 
            public FrmSymbol()
            { 
                InitializeComponent();
            }
    
            public ISymbol pSelSymbol;
            private IStyleGalleryItem pStyleGalleryItem;
            private ISymbologyStyleClass pSymStyleClass;
    		
    		//创建获取符号样式的事件对象
            public delegate void GetSelSymbolItemEventHandler(ref IStyleGalleryItem pStyleItem);
            public event GetSelSymbolItemEventHandler GetSelSymbolItem = null;
    
            string filepath = System.AppDomain.CurrentDomain.SetupInformation.ApplicationBase;
    
            private EnumMapSurroundType _enumMapSurType = EnumMapSurroundType.None;
            public EnumMapSurroundType EnumMapSurType
            { 
                get {  return _enumMapSurType; }
                set {  _enumMapSurType = value; }
            }
            public void InitUI()
            { 
                SymbologyCtrl.Clear();
                string StyleFilePath = filepath + "Symbol\\ESRI.ServerStyle";//获取系统符号库的路径
                SymbologyCtrl.LoadStyleFile(StyleFilePath);
                switch (_enumMapSurType)
                { 
                    case EnumMapSurroundType.NorthArrow://根据选择，载入系统指北针符号库
                        SymbologyCtrl.StyleClass = esriSymbologyStyleClass.esriStyleClassNorthArrows;
                        pSymStyleClass = SymbologyCtrl.GetStyleClass(esriSymbologyStyleClass.esriStyleClassNorthArrows);
                        break;
                    case EnumMapSurroundType.ScaleBar://根据选择，载入系统比例尺符号库
                        SymbologyCtrl.StyleClass = esriSymbologyStyleClass.esriStyleClassScaleBars;
                        pSymStyleClass = SymbologyCtrl.GetStyleClass(esriSymbologyStyleClass.esriStyleClassScaleBars);
                        break;
                }
                pSymStyleClass.UnselectItem();
            }
            private void simpleButton_OK_Click(object sender, EventArgs e)
            { 
                GetSelSymbolItem(ref pStyleGalleryItem);//传递用户选择的值
                this.Close();
            }
    
            private void simpleButton_Cancel_Click(object sender, EventArgs e)
            { 
                GetSelSymbolItem(ref pStyleGalleryItem);//传递用户选择的值
                this.Close();
            }
    
            private void SymbologyCtrl_OnMouseDown(object sender, AxESRI.ArcGIS.Controls.ISymbologyControlEvents_OnMouseDownEvent e)
            { 
                try
                { 
                    pStyleGalleryItem = SymbologyCtrl.HitTest(e.x, e.y);//用户选择需要符号 
                }
                catch (Exception ex)
                { 
    
                }
            }
        }

OperatePageLayout.cs:

class OperatePageLayout
        { 
            #region RGB颜色
            /// <summary>
            /// RGB颜色设置
            /// </summary>
            /// <param name="intR"></param>
            /// <param name="intG"></param>
            /// <param name="intB"></param>
            /// <returns></returns>
            public IRgbColor GetRgbColor(int intR, int intG, int intB)
            { 
                IRgbColor pRgbColor = null;
                if (intR < 0 || intR > 255 || intG < 0 || intG > 255 || intB < 0 || intB > 255)
                { 
                    return pRgbColor;
                }
                pRgbColor = new RgbColorClass();
                pRgbColor.Red = intR;
                pRgbColor.Green = intG;
                pRgbColor.Blue = intB;
                return pRgbColor;
            }
            #endregion
    
            #region 获取指定路径文件夹下子文件夹名称
            /// <summary>
            /// 获取指定路径文件夹下子文件夹名称
            /// </summary>
            /// <param name="sDirPath"></param>
            /// <returns></returns>
            public static List<string> GetChildDirectoryName(string sDirPath)
            { 
                List<string> plstDirName = null;
                try
                { 
                    string sDirName = string.Empty;
                    plstDirName = new List<string>();
                    DirectoryInfo _direcInfo = new DirectoryInfo(sDirPath);
                    DirectoryInfo[] _dirInfo = _direcInfo.GetDirectories();
                    foreach (DirectoryInfo _directoryInfo in _dirInfo)
                    { 
                        sDirName = _directoryInfo.Name;
                        if (!plstDirName.Contains(sDirName))
                        { 
                            plstDirName.Add(sDirName);
                        }
                    }
                }
                catch (Exception ex)
                { 
                }
                return plstDirName;
            }
            #endregion
            #region 获取指定文件夹下文件名称
            /// <summary>
            /// 获取指定文件夹下文件名称
            /// </summary>
            /// <param name="sDirPath"></param>
            /// <returns></returns>
            public static List<string> GetFiles(string sDirPath)
            { 
                List<string> plstFileName = null;
                try
                { 
                    FileInfo[] _fileInfo = null;
                    string sFileName = string.Empty;
                    plstFileName = new List<string>();
    
                    DirectoryInfo _direcInfo = new DirectoryInfo(sDirPath);
                    _fileInfo = _direcInfo.GetFiles();
                    foreach (FileInfo _fInfo in _fileInfo)
                    { 
                        sFileName = _fInfo.Name;
                        if (!plstFileName.Contains(sFileName))
                        { 
                            plstFileName.Add(sFileName);
                        }
                    }
                }
                catch (Exception ex)
                { 
                }
                return plstFileName;
            }
            #endregion
            #region 模板替换
            /// <summary>
            /// 模板替换
            /// </summary>
            /// <param name="_pageLayoutCtrl"></param>
            /// <param name="sTemplatePath"></param>
            /// <returns></returns>
            public static bool UseTemplateMxtToPageLayout(AxPageLayoutControl _pageLayoutCtrl, string sTemplatePath)
            { 
                bool bSuccess = false;
                try
                { 
                    IMap pMap = null;
                    IActiveView pActiveView = null;
                    IPageLayout pCurPageLayout = _pageLayoutCtrl.PageLayout;
                    pActiveView = pCurPageLayout as IActiveView;
                    pMap = pActiveView.FocusMap;
    
                    //读取模板
                    IMapDocument pTempMapDocument = new MapDocumentClass();
                    pTempMapDocument.Open(sTemplatePath, "");
    
                    IPageLayout pTempPageLayout = pTempMapDocument.PageLayout;
                    IPage pTempPage = pTempPageLayout.Page;
                    IPage pCurPage = pCurPageLayout.Page;
    
                    //替换单位及地图方向
                    pCurPage.Orientation = pTempPage.Orientation;
                    pCurPage.Units = pTempPage.Units;
    
                    //替换页面尺寸
                    Double dWidth; Double dHeight;
                    pTempPage.QuerySize(out dWidth, out dHeight);
                    pCurPage.PutCustomSize(dWidth, dHeight);
    
                    //删除当前layout中除了mapframe外的所有element
                    IGraphicsContainer pGraph;
                    pGraph = pCurPageLayout as IGraphicsContainer;
                    pGraph.Reset();
                    IElement pElement = pGraph.Next();
                    IMapFrame pMapFrame = null;
                    pMapFrame = pGraph.FindFrame(pMap) as IMapFrame;
                    while (pElement != null)
                    { 
                        if (pElement is IMapFrame)
                        { 
                            pMapFrame = pElement as IMapFrame;
                        }
                        else
                        { 
                            pGraph.DeleteElement(pElement);
                            pGraph.Reset();
                        }
                        pElement = pGraph.Next();
                    }
    
                    //遍历模板中的PageLayout所有元素，替换当前PageLayout的所有元素
                    IGraphicsContainer pTempGraph = pTempPageLayout as IGraphicsContainer;
                    pTempGraph.Reset();
                    pElement = pTempGraph.Next();
                    IArray pArray = new ArrayClass();
                    while (pElement != null)
                    { 
                        if (pElement is IMapFrame)
                        { 
                            IElement pMapFrameElement = pMapFrame as IElement;
                            pMapFrameElement.Geometry = pElement.Geometry;
                        }
                        else
                        { 
                            if (pElement is IMapSurroundFrame)
                            { 
                                IMapSurroundFrame pTempMapSurroundFrame = pElement as IMapSurroundFrame;
                                pTempMapSurroundFrame.MapFrame = pMapFrame;
                                IMapSurround pTempMapSurround = pTempMapSurroundFrame.MapSurround;
                            }
                            pArray.Add(pElement);
                        }
                        pElement = pTempGraph.Next();
                    }
    
                    int pElementCount = pArray.Count;
                    for (int i = 0; i < pArray.Count; i++)
                    { 
                        pGraph.AddElement(pArray.get_Element(pElementCount - 1 - i) as IElement, 0);
                    }
    
                    pActiveView.Refresh();
                    bSuccess = true;
                }
                catch (Exception ex)
                { 
    
                }
                return bSuccess;
            }
            #endregion 
        }

实现效果：  
(1)指北针  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2RheXVoYWl0YW5nMQ_size_16_color_FFFFFF_t_70 1]  
(2)比例尺  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2RheXVoYWl0YW5nMQ_size_16_color_FFFFFF_t_70 2]  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2RheXVoYWl0YW5nMQ_size_16_color_FFFFFF_t_70 3]

# 三、小结 #

这一部分的内容很容易会出错，不仅需要多个鼠标事件的配合，更是使用到了C\#语言中的事件的概念，也是因为感觉到这部分的代码过多，所以打算多写几篇笔记来记录一下。

> 参考资料：《ArcgisEngine地理信息系统开发教程》

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