1、线段绘制

基本步骤

构建形状

1. 创建 IPoint

IPoint m_Point = new PointClass();

m_Point.PutCoords(x, y);

2. 创建 IPointCollection

IPointCollection m_PointCollection = new PolylineClass();

m_PointCollection.AddPoint(m_Point, ref Type.Missing, ref Type.Missing);

3. 创建 IPolyline

IPolyline m_Polyline = new PolylineClass();

m_Polyline = m_PointCollection as IPolyline;

4. 创建 IElement

// Element 不能实例化，需要用其派生类实例化

IElement m_Element = m_SimpleLineSymbol as IElement;

m_Element.Geometry = m_Polyline;

设置形状样式

1. 创建 ISimpleLineSymbol

ISimpleLineSymbol m_SimpleLineSymbol = new SimpleLineSymbolClass();

2. 创建 ILineElement

ILineElement m_LineElement = new LineElementClass();

m_LineElement.Symbol = m_SimpleLineSymbol;

加载到地图

IMap m_Map = axMapControl1.Map;

IActiveView m_ActiveView = m_Map as IActiveView;

IGraphicsContainer m_Container = m_Map as IGraphicsContainer;

m_Container.AddElement(m_Element, 0);

m_Active.PartialRefresh(esriViewDrawPhase.esriViewGraphics, null, null);

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其他方法

private void DrawLine()  {      ILineElement pLineElement;      IElement pLElement;            IPolyline pLine;            RgbColor pColor = new RgbColor();      pColor.Red = 0;      pColor.Green = 0;      pColor.Blue = 255;            ISimpleLineSymbol pSimpleLineSymbol = new SimpleLineSymbolClass();      pSimpleLineSymbol.Color = pColor;      pSimpleLineSymbol.Width = 5;            pLineElement = new LineElementClass();      pLineElement.Symbol = pSimpleLineSymbol;            pLElement = pLineElement as IElement;            IRubberBand pRubberBand;      pRubberBand = new RubberLineClass();      pLine = pRubberBand.TrackNew(axMapControl1.ActiveView.ScreenDisplay, null) as IPolyline;            pLElement.Geometry = pLine;            IGraphicsContainer pGraphicsContainer;      pGraphicsContainer = axMapControl1.ActiveView as IGraphicsContainer; //把地图的当前view作为图片的容器            pGraphicsContainer.AddElement(pLElement, 0);//把刚刚的element转到容器上      axMapControl1.ActiveView.PartialRefresh(esriViewDrawPhase.esriViewGraphics, null, null);  }

View Code

2、编辑

点编辑：

IPoint pt;  pt = axMapControl1.ToMapPoint(e.x, e.y);  IMarkerElement pMarkerElement;  pMarkerElement = new MarkerElementClass();  IElement pElement;  pElement = pMarkerElement as IElement;  pElement.Geometry = pt;  pGraphicsContainer = pMap as IGraphicsContainer;  pGraphicsContainer.AddElement((IElement)pMarkerElement, 0);  pActiveView.Refresh();

线编辑：

IGeometry polyline;  polyline = axMapControl1.TrackLine();  ILineElement pLineElement;  pLineElement = new LineElementClass();  IElement pElement;  pElement = pLineElement as IElement;  pElement.Geometry = polyline;  pGraphicsContainer = pMap as IGraphicsContainer;  pGraphicsContainer.AddElement((IElement)pLineElement, 0);  pActiveView.Refresh();

面编辑：

IGeometry Polygon;  Polygon = axMapControl1.TrackPolygon();  IPolygonElement PolygonElement;  PolygonElement = new PolygonElementClass();  IElement pElement;  pElement = PolygonElement as IElement;  pElement.Geometry = Polygon;  pGraphicsContainer = pMap as IGraphicsContainer;  pGraphicsContainer.AddElement((IElement)PolygonElement, 0);  pActiveView.Refresh();

ArcEngine中画shape点的另一种方法

public override void OnMouseDown(int Button, int Shift, int X, int Y)  {           //base.OnMouseDown(Button, Shift, X, Y);      IFeatureLayer pFeatureLayer = mapControl.Map.get_Layer(0) as IFeatureLayer;      IFeatureClass fc = pFeatureLayer.FeatureClass;      IFeatureClassWrite fr = fc as IFeatureClassWrite;      IWorkspaceEdit pWorkspaceEdit = (fc as IDataset).Workspace as IWorkspaceEdit;            IFeature pFeature;      IPoint pPoint;      //开始事物操作      pWorkspaceEdit.StartEditing(false);            //开始编辑      pWorkspaceEdit.StartEditOperation();            pFeature = fc.CreateFeature();      pPoint = new PointClass();      IPoint Mp = mapControl.ToMapPoint(X, Y);      pPoint.PutCoords(Mp.X, Mp.Y);      pPoint.SpatialReference = mapControl.SpatialReference;      pFeature.Shape = pPoint;      pFeature.Store();      mapControl.ActiveView.Refresh();      if (Button == 2)      {          pWorkspaceEdit.StopEditOperation();          pWorkspaceEdit.StopEditing(true);      }  }

3、绘制Element、Symbol 在控件上

做符号预览的时候需要将ISymbol或IElement绘制到指定的控件上，下面边码边说，一起讨论讨论：

3.1 绘制在Panel上

ISymbol接口有Draw函数，查询其接口可以发现，我们需要执行ISymbol.SetupDC -> ISymbol.Draw -> ISymbol.ResetDC 这三个步骤；

首先SetupDC需要参数 hDC和IDisplayTransformation;贴代码：

例如：绘制在Panel上：

int width=Panel.Width;int heigth=Panel.Heigth;//绘制方法Graphics graph=Graphics.FromHwnd(Panel.Handle);graph.Clear(Panel.BackColor);//分辨率double dpi=graph.DpiX;IEnvelope pEnve=new EnvelopeClass();pEnve.PutCoords(0,0,width,heigth);Ipoint pCenterPt=new PointClass;pCenter.PutCoords(width/2,height/2); tagRECT myRect=new tagRECT();设置MyRect 的 top=0；bottom=heigh; left=0,right=width;IDisplayransformation pDisTrans=new  DisplayTrabsformation();pDisTrans.VisiableBounds=pEnve;pDisTrans.Bounds=pEnv;pDisTrans.Set_DeviceFrame(ref myRect);pDisTrans.Resolution=dpi; intPtr hdc=graph.GetHdc();ISymbol.SetupDC(hec.ToInt32,pDisTrans);ISymbol.Draw(pCenterPt);ISymbol.ResetDC(); //绘制完成后 是否绘图对象 graph.ReleaseHdc(hdc);graph.Dispose();