ArcMap的Editor工具，实现要素拖动、编

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

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：

///

///

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。

///

///

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; } }

///

///

{ 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：

///

///

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;

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; }

///

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！

示例源码下载地址 http://download.csdn.net/source/947550

本文来源：https://www.bwwdw.com/article/pn72.html