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：
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。
转载地址 https://blog.csdn.net/huyanliang/article/details/75529819