编程创建共享参数（完整代码演示）

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原文链接： http://blog.csdn.net/joexiongjin/article/details/8098942
作者：  叶雄进 , Autodesk ADN

Revit提供了命令用户可以用来为对象添加共享参数，共享参数这个直译名字比较不容易理解。我觉得翻译成扩展参数比较好懂。就是你可以为某一类或几类对象创建更多的参数。这个参数可以显示在对象的参数属性对话框中，更多的关于共享参数请看Revit产品帮助。

Revit 也公共了API来创建共享参数。

创建共享参数的步骤和相关的类是这些：

§获得共享参数定义文件.

§ClassDefinitionFile

§Application.Options.SharedParametersFilename

§Application.OpenSharedParameterFile

§获得共享参数组.

§ClassAutodesk.Revit.Parameters.DefinitionGroup

§DefinitionFile.Groups

§DefinitionFile.Groups.Create

§获得共享参数定义,可设置共享参数可见性

§ClassParameters.Definition

§DefinitionGroup.Definitions

§DefinitionGroup.Definitions.Create

§创建Category集合,把需要添加共享参数对象的Category加入到集合中

§CategorySetcatSet =revitApp.Create.NewCategorySet()

§catSet.Insert(doc.Settings.Categories.Item(BuiltInCategory.OST_Doors ) )

§catSet.Insert(doc.Settings.Categories.Item(BuiltInCategory.OST_Windows ) )

§绑定参数,设置所在的参数组

§Dim binding AsParameters.Binding =revitApp.Create.NewInstanceBinding(catSet )

§doc.ParameterBindings.Insert(fireRatingParamDef, binding, parameterGroup)

共享参数的创建都需要共享参数文件的途径来实现。无法直接创建共享参数。

下面是创建共享参数的一段代码：

#region Copyright
//
// Copyright (C) 2010-2012 by Autodesk, Inc.
//
// Permission to use, copy, modify, and distribute this software in
// object code form for any purpose and without fee is hereby granted,
// provided that the above copyright notice appears in all copies and
// that both that copyright notice and the limited warranty and
// restricted rights notice below appear in all supporting
// documentation.
//
// AUTODESK PROVIDES THIS PROGRAM "AS IS" AND WITH ALL FAULTS.
// AUTODESK SPECIFICALLY DISCLAIMS ANY IMPLIED WARRANTY OF
// MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE.  AUTODESK, INC.
// DOES NOT WARRANT THAT THE OPERATION OF THE PROGRAM WILL BE
// UNINTERRUPTED OR ERROR FREE.
//
// Use, duplication, or disclosure by the U.S. Government is subject to
// restrictions set forth in FAR 52.227-19 (Commercial Computer
// Software - Restricted Rights) and DFAR 252.227-7013(c)(1)(ii)
// (Rights in Technical Data and Computer Software), as applicable.
//
// Ported from old rac labs by Jeremy Tammik
// 
#endregion // Copyright

#region Namespaces
using System;
using System.Diagnostics;
using System.Collections.Generic;
using Autodesk.Revit.ApplicationServices;
using Autodesk.Revit.Attributes;
using Autodesk.Revit.DB;
using Autodesk.Revit.UI;
using Autodesk.Revit.UI.Selection;
using Util;
using System.IO;
#endregion

namespace IntroCs
{
  /// <summary>
  /// Create a new shared parameter, then set and retrieve its value.
  /// In this example, we store a fire rating value on all doors.
  /// Please also look at the FireRating Revit SDK sample.
  /// </summary>
  [Transaction(TransactionMode.Automatic)]
  class SharedParameter : IExternalCommand
  {
    const string kSharedParamsGroupAPI = "API Parameters";
    const string kSharedParamsDefFireRating = "API FireRating";
    const string kSharedParamsPath = "C:\\temp\\SharedParams.txt";

    public Result Execute(
      ExternalCommandData commandData,
      ref string message,
      ElementSet elements)
    {
      UIDocument uidoc = commandData.Application.ActiveUIDocument;
      Application app = commandData.Application.Application; 
      Document doc = uidoc.Document;

      // Get the current shared params definition file
      DefinitionFile sharedParamsFile = GetSharedParamsFile(app);
      if (null == sharedParamsFile)
      {
        message = "Error getting the shared params file.";
        return Result.Failed;
      }

      // Get or create the shared params group
      DefinitionGroup sharedParamsGroup = GetOrCreateSharedParamsGroup(
        sharedParamsFile, kSharedParamsGroupAPI);
      if (null == sharedParamsGroup)
      {
        message = "Error getting the shared params group.";
        return Result.Failed;
      }

      Category cat = doc.Settings.Categories.get_Item(BuiltInCategory.OST_Doors);

      // Visibility of the new parameter:
      // Category.AllowsBoundParameters property indicates if a category can 
      // have shared or project parameters. If it is false, it may not be bound 
      // to shared parameters using the BindingMap. Please note that non-user-visible 
      // parameters can still be bound to these categories. 
      bool visible = cat.AllowsBoundParameters;

      // Get or create the shared params definition
      Definition fireRatingParamDef = GetOrCreateSharedParamsDefinition(
        sharedParamsGroup, ParameterType.Number, kSharedParamsDefFireRating, visible);
      if (null == fireRatingParamDef)
      {
        message = "Error in creating shared parameter.";
        return Result.Failed;
      }

      // Create the category set for binding and add the category
      // we are interested in, doors or walls or whatever:
      CategorySet catSet = app.Create.NewCategorySet();
      try
      {
        catSet.Insert(cat);
      }
      catch (Exception)
      {
        message = string.Format(
          "Error adding '{0}' category to parameters binding set.",
          cat.Name);
        return Result.Failed;
      }

      // Bind the param
      try
      {
        Binding binding = app.Create.NewInstanceBinding(catSet);
        // We could check if already bound, but looks like Insert will just ignore it in such case
        doc.ParameterBindings.Insert(fireRatingParamDef, binding);
      }
      catch (Exception ex)
      {
        message = ex.Message;
        return Result.Failed;
      }

      return Result.Succeeded;
    }

    /// <summary>
    /// Helper to get shared parameters file.
    /// </summary>
    public static DefinitionFile GetSharedParamsFile(Application app)
    {
      // Get current shared params file name
      string sharedParamsFileName;
      try
      {
        sharedParamsFileName = app.SharedParametersFilename;
      }
      catch (Exception ex)
      {
        TaskDialog.Show("Get shared params file", "No shared params file set:" + ex.Message);
        return null;
      }

      if (0 == sharedParamsFileName.Length ||
        !System.IO.File.Exists(sharedParamsFileName))
      {
        StreamWriter stream;
        stream = new StreamWriter(kSharedParamsPath);
        stream.Close();
        app.SharedParametersFilename = kSharedParamsPath;
        sharedParamsFileName = app.SharedParametersFilename;
      }

      // Get the current file object and return it
      DefinitionFile sharedParametersFile;
      try
      {
        sharedParametersFile = app.OpenSharedParameterFile();
      }
      catch (Exception ex)
      {
        TaskDialog.Show("Get shared params file", "Cannnot open shared params file:" + ex.Message);
        sharedParametersFile = null;
      }
      return sharedParametersFile;
    }

    public static DefinitionGroup GetOrCreateSharedParamsGroup(
     DefinitionFile sharedParametersFile,
     string groupName)
    {
      DefinitionGroup g = sharedParametersFile.Groups.get_Item(groupName);
      if (null == g)
      {
        try
        {
          g = sharedParametersFile.Groups.Create(groupName);
        }
        catch (Exception)
        {
          g = null;
        }
      }
      return g;
    }

    public static Definition GetOrCreateSharedParamsDefinition(
      DefinitionGroup defGroup,
      ParameterType defType,
      string defName,
      bool visible)
    {
      Definition definition = defGroup.Definitions.get_Item(defName);
      if (null == definition)
      {
        try
        {
          definition = defGroup.Definitions.Create(defName, defType, visible);
        }
        catch (Exception)
        {
          definition = null;
        }
      }
      return definition;
    }
  }

  [Transaction(TransactionMode.Automatic)]
  public class PerDocParameter : IExternalCommand
  {
    public const string kParamGroupName = "Per-doc Params";
    public const string kParamNameVisible = "Visible per-doc Integer";
    public const string kParamNameInvisible = "Invisible per-doc Integer";

    public Result Execute(
      ExternalCommandData commandData,
      ref string message,
      ElementSet elements)
    {
      UIDocument uiDoc = commandData.Application.ActiveUIDocument;
      Application app = commandData.Application.Application;
      Document doc = uiDoc.Document;

      // get the current shared params definition file
      DefinitionFile sharedParamsFile = SharedParameter.GetSharedParamsFile(app);
      if (null == sharedParamsFile)
      {
        TaskDialog.Show("Per document parameter", "Error getting the shared params file.");
        return Result.Failed;
      }
      // get or create the shared params group
      DefinitionGroup sharedParamsGroup = SharedParameter.GetOrCreateSharedParamsGroup(sharedParamsFile, kParamGroupName);
      if (null == sharedParamsGroup)
      {
        TaskDialog.Show("Per document parameter", "Error getting the shared params group.");
        return Result.Failed;
      }
      // visible param
      Definition docParamDefVisible = SharedParameter.GetOrCreateSharedParamsDefinition(sharedParamsGroup, ParameterType.Integer, kParamNameVisible, true);
      if (null == docParamDefVisible)
      {
        TaskDialog.Show("Per document parameter", "Error creating visible per-doc parameter.");
        return Result.Failed;
      }
      // invisible param
      Definition docParamDefInvisible = SharedParameter.GetOrCreateSharedParamsDefinition(sharedParamsGroup, ParameterType.Integer, kParamNameInvisible, false);
      if (null == docParamDefInvisible)
      {
        TaskDialog.Show("Per document parameter", "Error creating invisible per-doc parameter.");
        return Result.Failed;
      }
      // bind the param
      try
      {
        CategorySet catSet = app.Create.NewCategorySet();
        catSet.Insert(doc.Settings.Categories.get_Item(BuiltInCategory.OST_ProjectInformation));
        Binding binding = app.Create.NewInstanceBinding(catSet);
        doc.ParameterBindings.Insert(docParamDefVisible, binding);
        doc.ParameterBindings.Insert(docParamDefInvisible, binding);
      }
      catch (Exception e)
      {
        TaskDialog.Show("Per document parameter", "Error binding shared parameter: " + e.Message);
        return Result.Failed;
      }
      // set the initial values
      // get the singleton project info element
      Element projInfoElem = GetProjectInfoElem(doc);

      if (null == projInfoElem)
      {
        TaskDialog.Show("Per document parameter", "No project info elem found. Aborting command...");
        return Result.Failed;
      }
      // for simplicity, access params by name rather than by GUID:
      projInfoElem.get_Parameter(kParamNameVisible).Set(55);
      projInfoElem.get_Parameter(kParamNameInvisible).Set(0);
      return Result.Succeeded;
    }

    /// <summary>
    /// Return the one and only project information element using Revit 2009 filtering
    /// by searching for the "Project Information" category. Only one such element exists.
    /// </summary>
    public static Element GetProjectInfoElem(Document doc)
    {
      FilteredElementCollector collector = new FilteredElementCollector(doc);
      collector.OfCategory(BuiltInCategory.OST_ProjectInformation);
      IList<Element> elems = collector.ToElements();

      Debug.Assert(elems.Count == 1, "There should be exactly one of this object in the project"); 

      return elems[0]; 
    }
  }
}