ArcMap的Editor工具，实现要素拖动、编辑

本来根本没有写这个工具的意思，自己一直用的Ae自带的工具。虽然可控制力弱了一些，但终究还是凑或能用。一天，问到一个同学，想请教一下，居然以百般理由回绝。算了，秉承毛老人家的口号：自力更生，丰衣足食！好了，闲话少说，各位看官，咱步入正题了。

首先，说一下，所有的要素的更新、插入、删除最好放在编辑的Session 里面，即以一对StartEditing和StopEditing包裹。

一开始我的疑问在于，为什么我用IWorkspaceEdit的StartEditing方法后，怎么鼠标不会变成AcrMap里面Editor的开始编辑那样呢，为什么不能选中要素，为什么不能双击后编辑要素？原来，选中要素和使要素处于编辑状态还是要自己写的(经高人指点，呵呵)。

先介绍一下程序中用到的变量：

Code

private AxMapControl m_MapControl;//从外部传进来的MapControl控件

private ILayer m_SelectedLayer;//当前正在编辑的图层

private bool m_IsEdited = false;//当前是否处于编辑状态

private bool m_IsInUse = false;//这个其实我这里没有用到，这个实在创建新要素时用到的

private List<IFeature> m_SelectedFeature;//这个存储鼠标点击下，击中的要素

private IPoint m_CurrentMousePosition;//这个好像也没用到，记录当前鼠标的位置

private IDisplayFeedback m_FeedBack;//这个就是当前屏幕(鼠标动作)的反馈信息
那我们就按照逻辑顺序来一一展示这个到底是怎么做的。首先是，开始和结束编辑的代码：

/// <summary>

/// 开始编辑

/// </summary>

/// <param name="bWithUndoRedo"></param>

public void StartEditing(bool bWithUndoRedo)

{

if (m_SelectedLayer == null) return;

IFeatureLayer featureLayer = m_SelectedLayer as IFeatureLayer;

if (featureLayer == null) return;

IFeatureClass featureClass = featureLayer.FeatureClass;

if (featureClass == null) return;

IDataset dataset = featureClass as IDataset;

IWorkspaceEdit workspaceEdit = dataset.Workspace as IWorkspaceEdit;

try

{

workspaceEdit.StartEditing(bWithUndoRedo);

m_IsEdited = true;

}

catch

{

return;

}

}
当然你可以直接传进来IWorkspace，这个可根据你具体的需求，我这里用当前图层获取工作空间。

/// <summary>

/// 结束编辑

/// </summary>

/// <param name="bSave"></param>

public void StopEditing(bool bSave)

{

if (m_IsEdited)

{

m_IsEdited = false;

if (m_SelectedLayer == null) return;

IFeatureLayer featureLayer = m_SelectedLayer as IFeatureLayer;

if (featureLayer == null) return;

IFeatureClass featureClass = featureLayer.FeatureClass;

if (featureClass == null) return;

IDataset dataset = featureClass as IDataset;

IWorkspaceEdit workspaceEdit = dataset.Workspace as IWorkspaceEdit;

if (workspaceEdit.IsBeingEdited())

{

try

{

workspaceEdit.StopEditing(bSave);

}

catch

{

workspaceEdit.AbortEditOperation();

return;

}

}

}

}

开始编辑已经好了，然后就是鼠标点击要素时候，让其处于选中状态，我这里为了方便控制，我分成了两个函数写，给为看官也可以合并成一个：

public void GetFeatureOnMouseDown(int x, int y)

{

m_SelectedFeature.Clear();

try

{

if (m_SelectedLayer == null) return;

IFeatureLayer featureLayer = m_SelectedLayer as IFeatureLayer;

if (featureLayer == null) return;

IFeatureClass featureClass = featureLayer.FeatureClass;

if (featureClass == null) return;

IPoint point = m_MapControl.ActiveView.ScreenDisplay.DisplayTransformation.ToMapPoint(x, y);

IGeometry geometry = point as IGeometry;

double length = ConvertPixelsToMapUnits(4);

ITopologicalOperator pTopo = geometry as ITopologicalOperator;

IGeometry buffer = pTopo.Buffer(length);

geometry = buffer.Envelope as IGeometry;

ISpatialFilter spatialFilter = new SpatialFilterClass();

spatialFilter.Geometry = geometry;

switch (featureClass.ShapeType)

{

case esriGeometryType.esriGeometryPoint:

spatialFilter.SpatialRel = esriSpatialRelEnum.esriSpatialRelContains;

break;

case esriGeometryType.esriGeometryPolygon:

spatialFilter.SpatialRel = esriSpatialRelEnum.esriSpatialRelIntersects;

break;

case esriGeometryType.esriGeometryPolyline:

spatialFilter.SpatialRel = esriSpatialRelEnum.esriSpatialRelCrosses;

break;

}

spatialFilter.GeometryField = featureClass.ShapeFieldName;

IQueryFilter filter = spatialFilter as IQueryFilter;

IFeatureCursor cursor = featureClass.Search(filter, false);

IFeature pfeature = cursor.NextFeature();

while (pfeature != null)

{

m_SelectedFeature.Add(pfeature);

pfeature = cursor.NextFeature();

}

}

catch

{

return;

}

}

/// <summary>

/// 根据鼠标点击位置使击中要素处于高亮显示状态

/// </summary>

/// <param name="x"></param>

/// <param name="y"></param>

public void SelectOnMouseDown()

{

try

{

if (m_SelectedLayer == null) return;

m_MapControl.Map.ClearSelection();

m_MapControl.ActiveView.PartialRefresh(esriViewDrawPhase.esriViewGeoSelection, null, null);

foreach (IFeature feature in m_SelectedFeature.ToArray())

{

m_MapControl.Map.SelectFeature(m_SelectedLayer, feature);

}

m_MapControl.ActiveView.PartialRefresh(esriViewDrawPhase.esriViewGeoSelection, null, null);

}

catch

{ return; }

}
相信大家对第一个函数并不陌生吧？对的，就是用的空间查询，把点击中的要素放进容器，再用第二个函数进行高亮显示。这个地方注意，如果数据量比较多，强烈推荐用PartialRefresh 而不要用Refresh，参数的含义请参考帮助。

这个只是开始编辑后，可以用鼠标点击选中要素，使其处于高亮状态，然而，ArcMap里面双击要素怎么出现节点用以编辑呢？这个是要自己绘制到MapControl上面去的：

/// <summary>

/// 在要素上面绘制一个可拖拽的符号

/// </summary>

/// <param name="geometry"></param>

public void DrawEditSymbol(IGeometry geometry, IDisplay display)

{

IEngineEditProperties engineProperty = new EngineEditorClass();

ISymbol pointSymbol = engineProperty.SketchVertexSymbol as ISymbol;

ISymbol sketchSymbol = engineProperty.SketchSymbol as ISymbol;

ITopologicalOperator pTopo = geometry as ITopologicalOperator;

sketchSymbol.SetupDC(display.hDC, display.DisplayTransformation);

sketchSymbol.Draw(pTopo.Boundary);

IPointCollection pointCol = geometry as IPointCollection;

for (int i = 0; i < pointCol.PointCount; i++)

{

IPoint point = pointCol.get_Point(i);

pointSymbol.SetupDC(display.hDC, display.DisplayTransformation);

pointSymbol.Draw(point);

pointSymbol.ResetDC();

}

ESRI.ArcGIS.ADF.ComReleaser.ReleaseCOMObject(sketchSymbol);

ESRI.ArcGIS.ADF.ComReleaser.ReleaseCOMObject(pointSymbol);

ESRI.ArcGIS.ADF.ComReleaser.ReleaseCOMObject(engineProperty);

}

注意，这个函数是在MapControl的AfterDraw里面调用的，IDisplay参数，是AfterDraw事件的参数，我这里就没有画出来，类似ArcMap里面还有一个红色的节点，这里全是绿色的，因为红色对我的用处不大，也就没有必要了，当然各位看官可以自行修改，还有就是绘制符号的时候一定要记得释放内存哦~

现在，编辑状态做好了，但是现在只是雏形，因为它还没有响应任何鼠标事件，当鼠标悬停在绿色的节点上时并不会让你可以拖拽，所以我们还要做点工作。

那现在就开始如果鼠标悬停在绿色节点上时的代码吧：

public void SnapVertex(int x,int y,IGeometry snapContainer,ref bool vertexSnaped,ref bool contained)

{

IPoint point = m_MapControl.ActiveView.ScreenDisplay.DisplayTransformation.ToMapPoint(x, y);

IPoint pHitPoint = null;

double hitDist = -1, tol = -1;

int vertexIndex = -1, partIndex = -1;

bool vertex = false;

tol = ConvertPixelsToMapUnits(4);

IHitTest pHitTest = snapContainer as IHitTest;

bool bHit=pHitTest.HitTest(point, tol, esriGeometryHitPartType.esriGeometryPartVertex, pHitPoint, ref hitDist, ref partIndex, ref vertexIndex, ref vertex);

vertexSnaped = false;

contained = false;

if (bHit)

{

m_MapControl.MousePointer = esriControlsMousePointer.esriPointerCrosshair;

vertexSnaped = true;

return;

}

else

{

IRelationalOperator pRelOperator=null;

ITopologicalOperator pTopo = null;

IGeometry buffer = null;

IPolygon polygon = null;

switch (snapContainer.GeometryType)

{

case esriGeometryType.esriGeometryPolyline:

pTopo = snapContainer as ITopologicalOperator;

buffer=pTopo.Buffer(3);

polygon = buffer as IPolygon;

pRelOperator=polygon as IRelationalOperator;

break;

case esriGeometryType.esriGeometryPolygon:

polygon = snapContainer as IPolygon;

pRelOperator=polygon as IRelationalOperator;

break;

case esriGeometryType.esriGeometryPoint:

pTopo = snapContainer as ITopologicalOperator;

buffer = pTopo.Buffer(3);

polygon = buffer as IPolygon;

pRelOperator = polygon as IRelationalOperator;

break;

default:

break;

}

if (pRelOperator == null) return;

if (pRelOperator.Contains(point))

{

m_MapControl.MousePointer = esriControlsMousePointer.esriPointerSizeAll;

contained = true;

}

else m_MapControl.MousePointer = esriControlsMousePointer.esriPointerArrow;

return;

}

}
这里就是根据鼠标悬停的位置，来改变鼠标样式，抱歉的很，我没有从AE里面找到和ArcMap一样的鼠标样式，只要用一些简单的替代了，当然你可以自己定义，也可以打电话、发Email质问ESRI客服，如果你知道了，一定要告诉我，否则我诅咒你找不到女朋友！这个函数里面，我需要判断，鼠标是悬停在要素的节点上，还是悬停在要素内部了，这个对于后面处理是拽节点还是移动要素有很大的帮助。

这个根据鼠标悬停位置改变鼠标样式，还远远不够滴，当你悬停到绿色节点上时，按下鼠标时，就意味这拖拽开始，当鼠标左键按下并移动时，要出现像橡皮筋一样的连接线，当左键弹起时，就意味着拖拽结束，如果再按下左键，就意味着要素的编辑结束。这个怎么做到呢，请看下面的代码：

public bool EditFeature(int x,int y,IGeometry geometry)

{

GetFeatureOnMouseDown(x, y);

SelectOnMouseDown();

if(m_SelectedFeature.Count<1)return false;

if (geometry == null) return false;

IPoint pHitPoint=null;

double hitDist = 0, tol = 0;

int vertexIndex = 0, vertexOffset = 0, numVertices = 0, partIndex = 0;

bool vertex=false;

IFeature editedFeature = m_SelectedFeature[0];

point = m_MapControl.ActiveView.ScreenDisplay.DisplayTransformation.ToMapPoint(x, y);

tol = ConvertPixelsToMapUnits(4);

//IGeometry pGeo = editedFeature.Shape;

//m_EditingFeature = editedFeature;

try

{

switch (geometry.GeometryType)

{

case esriGeometryType.esriGeometryPoint:

m_FeedBack = new MovePointFeedbackClass();

m_FeedBack.Display = m_MapControl.ActiveView.ScreenDisplay;

IMovePointFeedback pointMove = m_FeedBack as IMovePointFeedback;

pointMove.Start(geometry as IPoint, point);

break;

case esriGeometryType.esriGeometryPolyline:

if (TestGeometryHit(tol, point, geometry, ref pHitPoint, ref hitDist, ref partIndex, ref vertexOffset, ref vertexIndex, ref vertex))

{

if(!vertex)

{

IGeometryCollection geometryColl = geometry as IGeometryCollection;

IPath path = geometryColl.get_Geometry(partIndex) as IPath;

IPointCollection pointColl = path as IPointCollection;

numVertices = pointColl.PointCount;

object missing = Type.Missing;

if (vertexIndex == 0)

{

object start = 1 as object;

pointColl.AddPoint(point, ref start, ref missing);

}

else

{

object objVertexIndex=vertexIndex as object;

pointColl.AddPoint(point, ref missing, ref objVertexIndex);

}

TestGeometryHit(tol, point, geometry, ref pHitPoint, ref hitDist, ref partIndex, ref vertexOffset, ref vertexIndex, ref vertex);

}

m_FeedBack = new LineMovePointFeedbackClass();

m_FeedBack.Display = m_MapControl.ActiveView.ScreenDisplay;

ILineMovePointFeedback lineMove = m_FeedBack as ILineMovePointFeedback;

lineMove.Start(geometry as IPolyline, vertexIndex, point);

}

else return false;

break;

case esriGeometryType.esriGeometryPolygon:

if (TestGeometryHit(tol, point, geometry, ref pHitPoint, ref hitDist, ref partIndex, ref vertexOffset, ref vertexIndex, ref vertex))

{

if(!vertex)

{

IGeometryCollection geometryColl = geometry as IGeometryCollection;

IPath path = geometryColl.get_Geometry(partIndex) as IPath;

IPointCollection pointColl = path as IPointCollection;

numVertices = pointColl.PointCount;

object missing = Type.Missing;

if (vertexIndex == 0)

{

object start = 1 as object;

pointColl.AddPoint(point, ref start, ref missing);

}

else

{

object objVertexIndex = vertexIndex as object;

pointColl.AddPoint(point, ref missing, ref objVertexIndex);

}

TestGeometryHit(tol, point, geometry, ref pHitPoint, ref hitDist, ref partIndex, ref vertexOffset, ref vertexIndex, ref vertex);

}

m_FeedBack = new PolygonMovePointFeedbackClass();

m_FeedBack.Display = m_MapControl.ActiveView.ScreenDisplay;

IPolygonMovePointFeedback polyMove = m_FeedBack as IPolygonMovePointFeedback;

polyMove.Start(geometry as IPolygon, vertexIndex + vertexOffset, point);

}

else return false;

break;

default:

break;

}

}

catch {return false;}

return true;

}

public void FeatureEditMouseMove(int x,int y)

{

if (m_FeedBack == null) return;

IPoint point = m_MapControl.ActiveView.ScreenDisplay.DisplayTransformation.ToMapPoint(x, y);

m_FeedBack.MoveTo(point);

}

public IGeometry EndFeatureEdit(int x, int y)

{

if (m_FeedBack == null) return null;

IGeometry geometry = null;

IPoint point = m_MapControl.ActiveView.ScreenDisplay.DisplayTransformation.ToMapPoint(x, y);

if ((m_FeedBack as IMovePointFeedback) != null)

{

IMovePointFeedback pointMove = m_FeedBack as IMovePointFeedback;

geometry = pointMove.Stop() as IGeometry;

}

else if ((m_FeedBack as ILineMovePointFeedback) != null)

{

ILineMovePointFeedback lineMove = m_FeedBack as ILineMovePointFeedback;

geometry = lineMove.Stop() as IGeometry;

}

else if ((m_FeedBack as IPolygonMovePointFeedback) != null)

{

IPolygonMovePointFeedback polyMove = m_FeedBack as IPolygonMovePointFeedback;

geometry = polyMove.Stop() as IGeometry;

}

m_FeedBack = null;

m_MapControl.ActiveView.PartialRefresh(esriViewDrawPhase.esriViewGeography, m_SelectedLayer, null);

return geometry;

}

呵，这个排版真的是很累啊，无法自动缩进，害的我只能一行一行的移动。第一个函数，自然是点击下绿色节点时触发，意味着，我们的拖拽就开始了；但是，但按着鼠标左键来回移动时怎么处理啊？呵呵，这就是第二个函数的所具备的功能，所以你要在MapControl 的MouseMove事件中添加这个函数；但是当你确定你移动的位置是最佳位置的时候，想停下来怎么办呢？这就是第三个函数来帮你了，也就意味着你的拖拽结束，并返回一个IGeometry，这个IGeometry就是你编辑过后要素的新的几何形状，并且当你移动结束左键弹起的时候，这个新的IGeometry也需要显示出来它的绿色的节点，所以重绘的时候需要这个IGeometry。

好了，我们快大功告成了，stop！好像还少点东西，对了，我们最终是要把最新的几何形状赋给编辑的要素以实现更新，所以我们还需要下面的这个函数：

public bool UpdateEdit(IGeometry newGeom)

{

if (m_SelectedFeature.Count < 1) return false;

if (newGeom == null) return false;

if (newGeom.IsEmpty) return false;

IFeature feature = m_SelectedFeature[0];

IDataset dataset = feature.Class as IDataset;

IWorkspaceEdit workspaceEdit = dataset.Workspace as IWorkspaceEdit;

if (!workspaceEdit.IsBeingEdited()) return false;

workspaceEdit.StartEditOperation();

feature.Shape = newGeom;

feature.Store();

workspaceEdit.StopEditOperation();

m_SelectedFeature.Clear();

m_SelectedFeature.Add(feature);

ClearSelection();

return true;

}

呵呵，对的，这个函数很简单，就是更新一下编辑要素的几何形状，注意啊，这里我获取当前编辑的要素是从容器中取出来的，这样是不是很方便啊？这样我们就可以更新一个要素了。别忘了最后记得调用StopEditing以保存你的编辑！

当然，不可能一次性做好，我们需要更人性化一点，我们需要添加撤销和重做：

public void UndoEdit()

{

if (m_SelectedLayer == null) return;

IFeatureLayer featLayer = m_SelectedLayer as IFeatureLayer;

IDataset dataset = featLayer.FeatureClass as IDataset;

IWorkspaceEdit workspaceEdit = dataset.Workspace as IWorkspaceEdit;

bool bHasUndos = false;

workspaceEdit.HasUndos(ref bHasUndos);

if(bHasUndos)

{

workspaceEdit.UndoEditOperation();

}

ClearSelection();

}

public void RedoEdit()

{

if (m_SelectedLayer == null) return;

IFeatureLayer featLayer = m_SelectedLayer as IFeatureLayer;

IDataset dataset = featLayer.FeatureClass as IDataset;

IWorkspaceEdit workspaceEdit = dataset.Workspace as IWorkspaceEdit;

bool bHasUndos = false;

workspaceEdit.HasRedos(ref bHasUndos);

if (bHasUndos)

{

workspaceEdit.RedoEditOperation();

}

ClearSelection();

}

呵呵 这个也是很简单，对吧？这里需要给出几个上述函数中用到的辅助函数，这里就不一一阐明了，请各位看官自行分析：

private double ConvertPixelsToMapUnits(double pixelUnits)

{

int pixelExtent = m_MapControl.ActiveView.ScreenDisplay.DisplayTransformation.get_DeviceFrame().right- m_MapControl.ActiveView.ScreenDisplay.DisplayTransformation.get_DeviceFrame().left;

double realWorldDisplayExtent = m_MapControl.ActiveView.ScreenDisplay.DisplayTransformation.VisibleBounds.Width;

double sizeOfOnePixel = realWorldDisplayExtent / pixelExtent;

return pixelUnits * sizeOfOnePixel;

}

private bool TestGeometryHit(double tol,IPoint pPoint,IGeometry geometry,ref IPoint pHitPoint,

ref double hitDist, ref int partIndex, ref int vertexOffset,

ref int vertexIndex, ref bool vertexHit)

{

IHitTest pHitTest = geometry as IHitTest;

pHitPoint = new PointClass();

bool last = true;

bool res = false;

if (pHitTest.HitTest(pPoint, tol, esriGeometryHitPartType.esriGeometryPartVertex, pHitPoint, ref hitDist, ref partIndex, ref vertexIndex, ref last))

{

vertexHit = true;

res = true;

}

else

{

if (pHitTest.HitTest(pPoint, tol, esriGeometryHitPartType.esriGeometryPartBoundary, pHitPoint, ref hitDist, ref partIndex, ref vertexIndex, ref last))

{

vertexHit = false;

res = true;

}

}

if(partIndex>0)

{

IGeometryCollection pGeoColl = geometry as IGeometryCollection;

vertexOffset = 0;

for (int i = 0; i < partIndex;i=2*i+1)

{

IPointCollection pointColl = pGeoColl.get_Geometry(i) as IPointCollection;

vertexOffset = vertexOffset + pointColl.PointCount;

}

}

return res;

}

/// <summary>

/// 清除要素选择状态，恢复常态

/// </summary>

public void ClearSelection()

{

m_MapControl.Map.ClearSelection();

m_MapControl.ActiveView.PartialRefresh(esriViewDrawPhase.esriViewGeography, m_SelectedLayer, null);

}

各位看官，由于要素的移动、要素的创建和要素编辑在代码逻辑上差不多，所以我就不做过多阐述了，都是在处理鼠标的事件，需要做判断。其实，可能有看官已经了解，在AE的帮助里面就有类似的代码，是的，我参考了这部分代码，并对ESRI的开发和工作人员表示感谢。

最后，谢谢AE开发群一叶知秋老大哥的帮助，总是在繁忙之中耐心的指导，再次表示感谢。

希望大家能够有所启发，谢谢大家的支持！

最后需要示例源码的请联系我，我的邮箱是lipengguo.cz # gmail.com