创建和编辑AutoCAD图元 > 使用选择集 > 定义选择集过滤规则 > 
过滤扩展数据
 
 

External applications can attach data such as text strings, numeric values, 3D points, distances, and layer names to AutoCAD objects. This data is referred to as extended data, or xdata. You can filter entities containing extended data for a specified application.

外部应用程序可以向 AutoCAD 对象附加数据，例如文字字符串、数值、三维点、距离和图层名。这种数据称为外部数据或 Xdata。用户可以过滤包含指定的应用程序外部数据的图元。

选择包含外部数据的圆

The following example filters for circles containing xdata added by the “MY_APP” application:

下例将通过过滤查找出包含通过“MY_APP”应用程序添加的外部数据的圆：

VB.NET 

Imports Autodesk.AutoCAD.Runtime
Imports Autodesk.AutoCAD.ApplicationServices
Imports Autodesk.AutoCAD.DatabaseServices
Imports Autodesk.AutoCAD.EditorInput
 
<CommandMethod("FilterXdata")> _
Public Sub FilterXdata()
  '' 获得当前文档的编辑器     Get the current document editor
  Dim acDocEd As Editor = Application.DocumentManager.MdiActiveDocument.Editor
 
  '' 创建一个 TypedValue 数组，用于定义过滤条件    Create a TypedValue array to define the filter criteria
  Dim acTypValAr(1) As TypedValue
  acTypValAr.SetValue(New TypedValue(DxfCode.Start, "Circle"), 0)
  acTypValAr.SetValue(New TypedValue(DxfCode.ExtendedDataRegAppName, _
                                     "MY_APP"), 1)
 
  '' 赋值过滤条件给 SelectionFilter 对象    Assign the filter criteria to a SelectionFilter object
  Dim acSelFtr As SelectionFilter = New SelectionFilter(acTypValAr)
 
  '' 要求在图形区域中选择对象    Request for objects to be selected in the drawing area
  Dim acSSPrompt As PromptSelectionResult
  acSSPrompt = acDocEd.GetSelection(acSelFtr)
 
  '' 如果提示状态是 OK，对象就被选择了    If the prompt status is OK, objects were selected
  If acSSPrompt.Status = PromptStatus.OK Then
      Dim acSSet As SelectionSet = acSSPrompt.Value
 
      Application.ShowAlertDialog("Number of objects selected: " & _
                                  acSSet.Count.ToString())
  Else
      Application.ShowAlertDialog("Number of objects selected: 0")
  End If
End Sub

C# 

using Autodesk.AutoCAD.Runtime;
using Autodesk.AutoCAD.ApplicationServices;
using Autodesk.AutoCAD.DatabaseServices;
using Autodesk.AutoCAD.EditorInput;
 
[CommandMethod("FilterXdata")]
public static void FilterXdata()
{
  // 获得当前文档的编辑器     Get the current document editor
  Editor acDocEd = Application.DocumentManager.MdiActiveDocument.Editor;
 
  // 创建一个 TypedValue 数组，用于定义过滤条件    Create a TypedValue array to define the filter criteria
  TypedValue[] acTypValAr = new TypedValue[2];
  acTypValAr.SetValue(new TypedValue((int)DxfCode.Start, "Circle"), 0);
  acTypValAr.SetValue(new TypedValue((int)DxfCode.ExtendedDataRegAppName,
                                     "MY_APP"), 1);
 
  // 赋值过滤条件给 SelectionFilter 对象    Assign the filter criteria to a SelectionFilter object
  SelectionFilter acSelFtr = new SelectionFilter(acTypValAr);
 
  // 要求在图形区域中选择对象    Request for objects to be selected in the drawing area
  PromptSelectionResult acSSPrompt;
  acSSPrompt = acDocEd.GetSelection(acSelFtr);
 
  // 如果提示状态是 OK，对象就被选择了    If the prompt status is OK, objects were selected
  if (acSSPrompt.Status == PromptStatus.OK)
  {
      SelectionSet acSSet = acSSPrompt.Value;
 
      Application.ShowAlertDialog("Number of objects selected: " +
                                  acSSet.Count.ToString());
  }
  else
  {
      Application.ShowAlertDialog("Number of objects selected: 0");
  }
}
VBA/ActiveX 代码参考