ArcGIS Engine 中的绘制与编辑

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();