一.什麼是Schema

Schema是Revit擴充套件資料的技術關鍵詞,revit到這裡，需要對Revit二開基礎有一定了解。

二.Schema架構

建立revit擴充套件資料第一步是建立Schema（類似建立架構設計，設計Schema儲存結構，類似設計DB 資料表結構），第二步是將擴充套件資料放入Entity，最終儲存的位置在Element。

三.程式碼

SchemaMaager

public class SchemaManager
    {
        private static SchemaManager instance;
        
 
public static SchemaManager Current
        {
            get 
            { 
                if(instance == null)
                    instance = new SchemaManager();
                return instance;
            }
        }

        protected SchemaManager() { }


        public Schema CreateSchema(Guid id,string
 
 name,string documentation,AccessLevel readAccessLevel,AccessLevel writeAccessLevel,
            string[] fieldNames,string vendorID = "ADSK")
        {
            if (GetSchema(id) != null)
                return GetSchema(id);

            SchemaBuilder schemaBuilder = new SchemaBuilder(id);
            schemaBuilder.SetSchemaName(name);
            schemaBuilder.SetDocumentation(documentation);
            schemaBuilder.SetReadAccessLevel(readAccessLevel);
            schemaBuilder.SetWriteAccessLevel(writeAccessLevel);
            schemaBuilder.SetVendorId(vendorID);
            
 
foreach(var fieldName in fieldNames)
            {
                schemaBuilder.AddSimpleField(fieldName, typeof(string));
            }
            return schemaBuilder.Finish();
        }

        
        public Schema GetSchema(Guid id)
        {
            return Schema.Lookup(id);
        }


        public void SetEntity<T>(Element element,Guid schemaId,string fieldName,T data)
        {
            Entity ent = element.GetEntity(GetSchema(schemaId));

            if (ent.Schema == null)
                ent = new Entity(schemaId);
            ent.Set(fieldName, JsonConvert.SerializeObject(data));
            element.SetEntity(ent);
        }

        public void SetEntity(Element element, Guid schemaId, string fieldName, string data)
        {
            Entity ent = element.GetEntity(GetSchema(schemaId));

            if (ent.Schema == null)
                ent = new Entity(schemaId);
            ent.Set(fieldName, data);
            element.SetEntity(ent);
        }


    }

SchemaCreater

  public class SchemaCreater
    {
        public static void CreateSchemaOfID()
        {
            SchemaManager.Current.CreateSchema(SchemaIds.IDData, "Schema_ID", "Schema id data", 
                Autodesk.Revit.DB.ExtensibleStorage.AccessLevel.Public,
                Autodesk.Revit.DB.ExtensibleStorage.AccessLevel.Vendor, 
                new string[] {SchemaFields.JackExt });
        }
    }

測試程式碼：

  //擴充套件資料測試
    [Autodesk.Revit.Attributes.Transaction(Autodesk.Revit.Attributes.TransactionMode.Manual)]
    [Autodesk.Revit.Attributes.Regeneration(Autodesk.Revit.Attributes.RegenerationOption.Manual)]
    public class SchemaDataTest : IExternalCommand
    {
       
        public Result Execute(ExternalCommandData commandData, ref string message, ElementSet elements)
        {
            Document doc = commandData.Application.ActiveUIDocument.Document;
            SchemaData.SchemaCreater.CreateSchemaOfID();    //建立Schema

            Wall wall = WallHelper.CreateWall(commandData);
            UIDocument uiDocument = commandData.Application.ActiveUIDocument;

            if (wall != null)
            {
                using (Transaction trans = new Transaction(doc))
                {
                    trans.Start("jack");
                    SchemaData.SchemaManager.Current.SetEntity(wall, SchemaIds.IDData, SchemaFields.JackExt, "jack_e920572f-ba66-4af8-99d6-498d97fe0bfe");
                    trans.Commit();
                }

                return Result.Succeeded;
            }
            else
                return Result.Failed;
        }
    }

程式碼架構：

原始碼下載：

https://files.cnblogs.com/files/xiaowangzi1987/RevitTestPro.rar

三.注意

1.建立Schema不需要開啟事務

2.當writeAccessLevel或readAccessLevel為Vendor的時候,vendorId必須與Addin檔案中的VendorId保持一致,否則會沒有寫(讀)擴充套件資料的許可權,並丟擲異常;

3.一個Entity可以有多個Schema，一個Schema可以有多個Field 。

如果有一個實體類需要存為擴充套件資料，方法一：建立一個Field，將實體類JSON序列化，儲存字串。 方法二：建立多個Field，一個Field對應實體類的屬性欄位。 方法三：建立多個Schema，一個Schema建一個Field,一個Field對應實體類的屬性欄位。