这个系列好久没有更新了，时间拖得太久了，一来是工作确实忙，出差比较多；二来，最近公司有点动荡，部门独立出来成立一个公司，有些其他事情耽搁了；三来，懒。这篇文章将介绍一下图层树，图层树的英文简写是Toc，全程Table of content。
ArcMap的TOC功能很强大，基本上我在实现TOC的时候，也是照虎画猫（我实现的这个和ArcMap比起来就是一只小猫，蛮丑的小猫）。闲话少扯，进入正题。
Toc的功能包括：
1、显示（调整）图层组织结构
2、对图层的显示/隐藏状态进行控制
3、提供针对图层的特殊操作，包括数据导出、选择集管理、属性设置等
Toc控件本身较为简单，继承了UserControl的一个用户自定义控件，增加了图层顺序拖动调整的功能。通过与右键菜单的结合，展示出了丰富的功能。
在实现右键菜单时，首先要获取在Toc中选中的对象类型及状态，比如：如果选中的是FeatureLayer，那就可以进行数据导出、选择集操作，如果选中的FeatureLayer对应的FeatureClass的GeometryType是Polygon，就显示“设置为工作区域”菜单……
要达到这个目的，就需要在Toc控件中对外公开一个当前选中对象的属性—SelectItem。具体的定义如下：
public partial class TocControl : UserControl
{
..........
#region 属性定义
public object BuddyControl
{
get
{
return this.axTOCControl1.Buddy;
}
set
{
this.axTOCControl1.SetBuddyControl(value);
}
}
/// <summary>
/// 获取当前图层
/// </summary>
public ESRI.ArcGIS.Carto.ILayer CurrentLayer
{
get
{
return m_layer;
}
}
private SelectItem selectedItem = null;
/// <summary>
/// 当前选中的对象
/// </summary>
public SelectItem SeletedItem
{
get
{
return this.selectedItem;
}
}
#endregion
private void GetSelectItem(int x,int y)
{
esriTOCControlItem item = esriTOCControlItem.esriTOCControlItemNone;
ILayer layer = null;
IBasicMap map = null;
this.axTOCControl1.HitTest(x, y, ref item, ref map, ref layer, ref m_other, ref m_index);
switch (item)
{
case esriTOCControlItem.esriTOCControlItemLayer:
this.selectedItem = new SelectItem(item, layer);
break;
case esriTOCControlItem.esriTOCControlItemMap:
this.selectedItem = new SelectItem(item, map);
break;
case esriTOCControlItem.esriTOCControlItemLegendClass:
this.selectedItem = new SelectItem(item, m_other);
break;
case esriTOCControlItem.esriTOCControlItemHeading:
this.selectedItem = new SelectItem(item, null);
break;
case esriTOCControlItem.esriTOCControlItemNone:
this.selectedItem = null;
break;
default:
this.selectedItem = null;
break;
}
}
public class SelectItem
{
public SelectItem(esriTOCControlItem type,object obj)
{
this.itemType = type;
this.itemObject = obj;
}
private esriTOCControlItem itemType = esriTOCControlItem.esriTOCControlItemLayer;
public esriTOCControlItem ItemType
{
get { return itemType; }
set { itemType = value; }
}
private object itemObject = null;
public object ItemObject
{
get { return itemObject; }
set { itemObject = value; }
}
}
..........
}
接下来做的就是需要根据Toc的SelectItem类型进行菜单显示状态控制。大家或许已经猜到了实现方法——使用IConditionEvaluator。没错，在我的框架中，为Toc控件实现了两个ConditionEvaluator，分别是TocItemSelectedConditionEvaluator和LayerFeatureSelectedConditionEvaluator。
TocItemSelectedConditionEvaluator用来判断Toc当前选中对象的具体类型，实现代码：
/// <summary>
/// Toc控件选择对象条件计算器
/// Toc控件选择对象类型包括：图层:layer,feautrelayer,rasterlayer,grouplayer，地图:map，图例:legend
/// wangyuxiang 2010-12-16
/// </summary>
class TocItemSelectedConditionEvaluator : IConditionEvaluator
{
public bool IsValid(object caller, Condition condition)
{
if (WorkbenchSingleton.Workbench == null) {
return false;
}
string itemtype = condition.Properties["itemtype"];
GISP.Lib.ArcGIS.ArcMap.GUI.MapDisplayBinding.TocControl tocControl = null;
foreach (PadDescriptor pad in WorkbenchSingleton.Workbench.PadContentCollection)
{
if (pad.PadContent != null && pad.PadContent.Control is GISP.Lib.ArcGIS.ArcMap.GUI.MapDisplayBinding.TocControl)
{
tocControl = pad.PadContent.Control as GISP.Lib.ArcGIS.ArcMap.GUI.MapDisplayBinding.TocControl;
if (tocControl.SeletedItem != null)
{
if (itemtype == "*")
{
return true;
}
if (Convert.ToString(itemtype).ToLower().Equals("layer"))
{
return tocControl.SeletedItem.ItemType == ESRI.ArcGIS.Controls.esriTOCControlItem.esriTOCControlItemLayer;
}
else if (Convert.ToString(itemtype).ToLower().Equals("map"))
{
return tocControl.SeletedItem.ItemType == ESRI.ArcGIS.Controls.esriTOCControlItem.esriTOCControlItemMap;
}
else if (Convert.ToString(itemtype).ToLower().Equals("legend"))
{
return tocControl.SeletedItem.ItemType == ESRI.ArcGIS.Controls.esriTOCControlItem.esriTOCControlItemLegendClass;
}
else if (Convert.ToString(itemtype).ToLower().Equals("featurelayer"))
{
return (tocControl.SeletedItem.ItemType == ESRI.ArcGIS.Controls.esriTOCControlItem.esriTOCControlItemLayer && tocControl.SeletedItem.ItemObject is IFeatureLayer);
}
else if (Convert.ToString(itemtype).ToLower().Equals("rasterlayer"))
{
return (tocControl.SeletedItem.ItemType == ESRI.ArcGIS.Controls.esriTOCControlItem.esriTOCControlItemLayer && tocControl.SeletedItem.ItemObject is IRasterLayer);
}
else if (Convert.ToString(itemtype).ToLower().Equals("grouplayer"))
{
return (tocControl.SeletedItem.ItemType == ESRI.ArcGIS.Controls.esriTOCControlItem.esriTOCControlItemLayer && tocControl.SeletedItem.ItemObject is IGroupLayer);
}
}
break;
}
}
return false;
}
}
LayerFeatureSelectedConditionEvaluator用来判断当前选中的FeatureLayer是否存在选择集，实现代码：
/// <summary>
/// 图层要素选择条件计算器
/// wangyuxiang 2010-12-17
/// </summary>
class LayerFeatureSelectedConditionEvaluator : IConditionEvaluator
{
public bool IsValid(object caller, Condition condition)
{
if (WorkbenchSingleton.Workbench == null) {
return false;
}
GISP.Lib.ArcGIS.ArcMap.GUI.MapDisplayBinding.TocControl tocControl = null;
foreach (PadDescriptor pad in WorkbenchSingleton.Workbench.PadContentCollection)
{
if (pad.PadContent.Control is GISP.Lib.ArcGIS.ArcMap.GUI.MapDisplayBinding.TocControl)
{
tocControl = pad.PadContent.Control as GISP.Lib.ArcGIS.ArcMap.GUI.MapDisplayBinding.TocControl;
if (tocControl.SeletedItem != null)
{
if (tocControl.SeletedItem.ItemObject is IFeatureLayer)
{
IFeatureSelection featureSelection = tocControl.SeletedItem.ItemObject as IFeatureSelection;
if (featureSelection != null)
{
ISelectionSet selectionSet = featureSelection.SelectionSet;
return (selectionSet != null && selectionSet.Count > 0);
}
}
}
break;
}
}
return false;
}
}
整个右键菜单的Addin配置如下：
<!--二维地图Toc控件右键菜单--> <Path name = "/SDF/Pads/ArcMap/TocPad/ContextMenu"> <Condition name = "TocItemSelected" itemtype="layer"> <MenuItem id = "RemoveLayer" type="ContextMenu" label = "移除" icon="ArcGIS.LayerTreeDelete16" class = "GISP.Addin.ArcMap.Commands.TocCommand_RemoveSelectedLayer"/> <MenuItem id = "RemoveLayer" type="ContextMenu" label = "标注" icon="ArcGIS.LayerTreeDelete16" class = "GISP.Addin.ArcMap.Commands.TocCommand_ShowLayerLabel"/> <ComplexCondition> <And> <Condition name = "TocItemSelected" itemtype="featurelayer" action="Disable"/> </And> <MenuItem id = "ZoomToLayer" type="ContextMenu" label = "查看属性表" icon ="ArcGIS.LayerTableOpen16" class = "GISP.Addin.ArcMap.Commands.TocCommand_ShowLayerAttribute"/> </ComplexCondition> <MenuItem id = "ZoomToLayer" type="ContextMenu" label = "缩放到图层" icon="GIS.MapControl.FullScreen" class = "GISP.Addin.ArcMap.Commands.TocCommand_ZoomToSelectedLayer"/> <ComplexCondition> <And> <Condition name = "MapScaleOutOfLayerScale" action="Disable"/> </And> <MenuItem id = "ZoomToVisible" type="ContextMenu" label = "缩放到图层显示比例尺" class = "GISP.Addin.ArcMap.Commands.TocCommand_ZoomToShowLayer"/> </ComplexCondition> <ComplexCondition> <And> <Condition name = "TocItemSelected" itemtype="featurelayer" action="Disable"/> </And> <MenuItem id = "LayerSection" label = "选择集" type ="Menu"> <ComplexCondition> <And> <Condition name = "LayerFeatureSelected" action="Disable"/> </And> <MenuItem id = "ZoomToSection" type="ContextMenu" label = "缩放到选中要素" icon="ArcGIS.ScreenPosition16" class = "GISP.Addin.ArcMap.Commands.TocCommand_ZoomToSelectedFeatures"/> <MenuItem id = "PanToSection" type="ContextMenu" label = "移动到选中要素" class = "GISP.Addin.ArcMap.Commands.TocCommand_PanToSelectedFeatures"/> <MenuItem id = "ClearSelectFeatures" type="ContextMenu" label = "取消选中状态" class = "GISP.Addin.ArcMap.Commands.TocCommand_ClearFeaturelayerSelection"/> <MenuItem id = "SwtichSelectFeatures" type="ContextMenu" label = "切换选中状态" class = ""/> <MenuItem id = "AddSelectFeaturesToWorkArea" type="ContextMenu" label = "添加到工作区域" class = "GISP.Addin.ArcMap.Commands.TocCommand_SetSelectFeaturesAsWorkAreas"/> </ComplexCondition> <ComplexCondition> <And> <Condition name = "WorkAreaIsValid" action="Disable"/> </And> <MenuItem id = "selectIntersectWIthWorkArea" type="ContextMenu" label = "选择工作区域内要素" icon="ArcGIS.GenericAddGreen16" class = "GISP.Addin.ArcMap.Commands.TocCommand_SelectFeaturesIntersectsWithWorkAreas"/> </ComplexCondition> <MenuItem id = "SelectAllFeatures" type="ContextMenu" label = "全部选中" class = "GISP.Addin.ArcMap.Commands.TocCommand_SelectAllFeatures"/> </MenuItem> </ComplexCondition> <ComplexCondition> <And> <Condition name = "TocItemSelected" itemtype="featurelayer" action="Disable"/> </And> <MenuItem id = "Separator" type = "Separator" /> <MenuItem id = "FeatureLayerData" label = "数据" icon="ArcGIS.ContentsWindowDrapedLayers16" type = "Menu"> <MenuItem id = "ExportFeatureLayerData" type="ContextMenu" label = "导出" icon="ArcGIS.LayerToLayer16" class = "GISP.Addin.ArcMap.Commands.TocCommand_ExportFeatureLayer"/> </MenuItem> <MenuItem id = "SetAsWorkArea" type="ContextMenu" label = "设置为工作区域" icon ="ArcGIS.GenericOptions16" class = "GISP.Addin.ArcMap.Commands.WorkArea_SetLayerAsWorkAreaCommand"/> <MenuItem id = "Separator" type = "Separator" /> </ComplexCondition> </Condition> <Condition name = "TocItemSelected" itemtype="*"> <MenuItem id = "LayerProperties" type="ContextMenu" label = "属性" icon ="ArcGIS.GenericOptions16" class = "GISP.Addin.ArcMap.Commands.TocCommand_ShowTocItemProperty"/> </Condition> </Path>
至此Toc控件Over，具体的右键菜单功能根据需求进行开发。