AE学习笔记之地图编辑（上）

        地图编辑这一部分还是挺复杂的，先看一下整个编辑过程的流程图（图1），再继续介绍每一步的细节信息和代码。



图1 流程图
具体步骤如下：
一、新建一个编辑工具栏
工具栏的样式如下，包括一下几个内容：编辑、选择、取消、重复、节点、移动、目标图层（Combox列表）、属性、保存、退出。各个控件的功能介绍如下：
编辑：该按钮是开始编辑按钮。
选择：单击该按钮可以选择地图上一定区域内的要素。
取消：取消本次编辑。
重复：回复上次编辑。
节点：对要素的节点信息进行编辑。
移动：移动选择的要素。
目标图层：显示当前地图中包含的矢量图层名。
属性：显示选择要素的属性信息。
保存：保存当前编辑内容。
退出：退出本次编辑。
        在对地图编辑之前需要将当前MapControl中包含的地图传入该类中。因此需要在类的Load函数中获取需要编辑的地图。



二、地图编辑
        不同的图层所具有的要素类型也不相同，整体可分为：单点、多点、线、面。在单击编辑时，打开编辑空间的开始编辑。
//开始编辑
public void StartEditing()
{
try
{
if (InEdit() == -1) return;
if (!(m_pCurrentLayer is ESRI.ArcGIS.Carto.IGeoFeatureLayer)) return;
ESRI.ArcGIS.Carto.IFeatureLayer pFeatureLayer = this.m_pCurrentLayer as ESRI.ArcGIS.Carto.IFeatureLayer;
ESRI.ArcGIS.Geodatabase.IDataset pDataset = pFeatureLayer.FeatureClass as ESRI.ArcGIS.Geodatabase.IDataset;
ESRI.ArcGIS.Geodatabase.IWorkspaceEdit pWorkspaceEdit = pDataset.Workspace as ESRI.ArcGIS.Geodatabase.IWorkspaceEdit;
if (!pWorkspaceEdit.IsBeingEdited())
{
pWorkspaceEdit.StartEditing(true);
pWorkspaceEdit.EnableUndoRedo();
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
以上包含了三步：
1.得到矢量图层中的要素类（FeatureClass）;
2.将要素类转化为数据集（IDataset）;
3.把要素集的工作空间转化为编辑工作空间，开始编辑（StartEditing(true)）。其中true表示是否启用UndoRedo，真表示启用。下面就接着：EnableUndoRedo();

        由于编辑时需要选择图层，就以目前图层中选择的图层作为当前编辑图层。然后根据图层的要素类型进行编辑：
         
//编辑
public void NewFeatureMouseDown(int x, int y)
{
ESRI.ArcGIS.Display.INewLineFeedback pNewLineFeedback;
ESRI.ArcGIS.Display.INewMultiPointFeedback pMultiPointFeedback;
ESRI.ArcGIS.Display.INewPolygonFeedback pPolygonFeedback;
try
{
if (this.InEdit() == -1) return;
ESRI.ArcGIS.Carto.IFeatureLayer pFeatureLayer = m_pCurrentLayer as ESRI.ArcGIS.Carto.IFeatureLayer;
ESRI.ArcGIS.Carto.IActiveView pActiveView = m_pMap as ESRI.ArcGIS.Carto.IActiveView;
ESRI.ArcGIS.Geometry.IPoint pPoint = pActiveView.ScreenDisplay.DisplayTransformation.ToMapPoint(x, y);
if (!m_bInUse)
{
this.m_pMap.ClearSelection();
switch (pFeatureLayer.FeatureClass.ShapeType)
{
case (ESRI.ArcGIS.Geometry.esriGeometryType.esriGeometryPoint):
CreateFeature(pPoint);
break;
case (ESRI.ArcGIS.Geometry.esriGeometryType.esriGeometryMultipoint):
m_bInUse = true;
this.m_pFeedback = new ESRI.ArcGIS.Display.NewMultiPointFeedbackClass();
pMultiPointFeedback = m_pFeedback as ESRI.ArcGIS.Display.INewMultiPointFeedback;
m_pPointCollection = new ESRI.ArcGIS.Geometry.Multipoint();
pMultiPointFeedback.Start(m_pPointCollection, pPoint);

break;
case (ESRI.ArcGIS.Geometry.esriGeometryType.esriGeometryPolyline):
m_bInUse = true;
this.m_pFeedback = new ESRI.ArcGIS.Display.NewLineFeedbackClass();
pNewLineFeedback = m_pFeedback as ESRI.ArcGIS.Display.INewLineFeedback;
pNewLineFeedback.Start(pPoint);
break;
case (ESRI.ArcGIS.Geometry.esriGeometryType.esriGeometryPolygon):
m_bInUse = true;
this.m_pFeedback = new ESRI.ArcGIS.Display.NewPolygonFeedbackClass();
pPolygonFeedback = m_pFeedback as ESRI.ArcGIS.Display.INewPolygonFeedback;
pPolygonFeedback.Start(pPoint);
break;
}
if (m_pFeedback != null)
m_pFeedback.Display = pActiveView.ScreenDisplay;
}
else
{
if (this.m_pFeedback is ESRI.ArcGIS.Display.INewMultiPointFeedback)
{
object obj = System.Reflection.Missing.Value;
m_pPointCollection.AddPoint(pPoint, ref obj, ref obj);
}
else if (this.m_pFeedback is ESRI.ArcGIS.Display.INewLineFeedback)
{
pNewLineFeedback = this.m_pFeedback as ESRI.ArcGIS.Display.INewLineFeedback;
pNewLineFeedback.AddPoint(pPoint);
}
else if (this.m_pFeedback is ESRI.ArcGIS.Display.INewPolygonFeedback)
{
pPolygonFeedback = this.m_pFeedback as ESRI.ArcGIS.Display.INewPolygonFeedback;
pPolygonFeedback.AddPoint(pPoint);
}
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
结束编辑：
public void NewFeatureEnd()
{
ESRI.ArcGIS.Geometry.IGeometry pGeometry = null;
ESRI.ArcGIS.Geometry.IPointCollection pPointCol = null;
try
{
if (this.m_pFeedback is ESRI.ArcGIS.Display.INewMultiPointFeedback)
{
ESRI.ArcGIS.Display.INewMultiPointFeedback pNewMultiPointFeedback = m_pFeedback as ESRI.ArcGIS.Display.INewMultiPointFeedback;
pNewMultiPointFeedback.Stop(); //返回值为Void
pGeometry = this.m_pPointCollection as ESRI.ArcGIS.Geometry.IGeometry;
}
else if (this.m_pFeedback is ESRI.ArcGIS.Display.INewLineFeedback)
{
ESRI.ArcGIS.Display.INewLineFeedback pNewLineFeedback = this.m_pFeedback as ESRI.ArcGIS.Display.INewLineFeedback;
ESRI.ArcGIS.Geometry.IPolyline pPolyline = pNewLineFeedback.Stop();
pPointCol = pPolyline as ESRI.ArcGIS.Geometry.IPointCollection;
if (pPointCol.PointCount < 2)
{
MessageBox.Show("至少输入两个节点");
return;
}
else
pGeometry = pPointCol as ESRI.ArcGIS.Geometry.IGeometry;
}
else if (this.m_pFeedback is ESRI.ArcGIS.Display.INewPolygonFeedback)
{
ESRI.ArcGIS.Display.INewPolygonFeedback pNewPolygonFeedback = this.m_pFeedback as ESRI.ArcGIS.Display.INewPolygonFeedback;
ESRI.ArcGIS.Geometry.IPolygon pPolygon = pNewPolygonFeedback.Stop();
pPointCol = pPolygon as ESRI.ArcGIS.Geometry.IPointCollection;
if (pPointCol.PointCount < 3)
{
MessageBox.Show("至少输入三个节点");
return;
}
else
pGeometry = pPointCol as ESRI.ArcGIS.Geometry.IGeometry;
}
CreateFeature(pGeometry);
m_pFeedback = null;
m_bInUse = false;
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);

}

}

结束编辑中的CreatFeature()函数：
public void CreateFeature(ESRI.ArcGIS.Geometry.IGeometry pGeometry)
{
try
{
if (pGeometry == null) return;
if (this.m_pCurrentLayer == null) return;
ESRI.ArcGIS.Geodatabase.IWorkspaceEdit pWorkspaceEdit = GetWorkspaceEdit();
ESRI.ArcGIS.Carto.IFeatureLayer pFeatureLayer = this.m_pCurrentLayer as ESRI.ArcGIS.Carto.IFeatureLayer;
ESRI.ArcGIS.Geodatabase.IFeatureClass pFeatureClass = pFeatureLayer.FeatureClass;
pWorkspaceEdit.StartEditOperation();
ESRI.ArcGIS.Geodatabase.IFeature pFeature = pFeatureClass.CreateFeature();
pFeature.Shape = pGeometry;
pFeature.Store();
pWorkspaceEdit.StopEditOperation();
this.m_pMap.SelectFeature(this.m_pCurrentLayer, pFeature);
ESRI.ArcGIS.Carto.IActiveView pActiveView = this.m_pMap as ESRI.ArcGIS.Carto.IActiveView;
pActiveView.Refresh();

}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}

        整个大体的框架就是这样，其中含包含的具体细节信息我会在下一节中在做详细的介绍。
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