[求助]求助一个关于扩展数据的问题

56854365

怎么样把以前添加的AutoCAD扩展数据更新成新的或删除

下面是网上找到的清除扩展数据的代码，我看不懂

void delXdata()
{
    ads_name eNam;
    
    ads_point pt;
    
    int ret = acedEntSel ("\nselect an object:", eNam, pt);  
    
    if ( ret!= RTNORM)    
    {
         return;    
    }
  
    AcDbObjectId ObjId;
  
    acdbGetObjectId(ObjId, eNam);
  
    AcDbEntity *pEnt;

    acdbOpenAcDbEntity(pEnt, ObjId, AcDb::kForWrite);

    resbuf *xdata = pEnt->xData(NULL);

    if (xdata)
    {
         xdata->rbnext = NULL;
  
         pEnt->setXData(xdata);
  
         acutRelRb(xdata);
    }
    
    pEnt->close();
}

heluyuan

         public void delXdata()

         {

              ads_name eNam;

   

              ads_point pt;

   

              int ret = acedEntSel ("\nselect an object:", eNam, pt);   //点选获得一个实体

   

              if ( ret!= RTNORM)   

              {

                   return;   

              }

 

              AcDbObjectId ObjId;

 

              acdbGetObjectId(ObjId, eNam);    //获得实体的ID

 

              AcDbEntity *pEnt;

 

              acdbOpenAcDbEntity(pEnt, ObjId, AcDb::kForWrite);  //通过ObjectID打开实体来编辑

 

              resbuf *xdata = pEnt->xData(NULL);   //获取实体的扩展数据结果缓冲区链表

 

              if (xdata)    //如果该扩展数据结果缓冲区链表不为空

              {

                   xdata->rbnext = NULL;  //将该结果缓冲区链表的后续指针置为空

 

                   pEnt->setXData(xdata); //将该实体的扩展数据设为置为空了的结果缓冲区

  

                   acutRelRb(xdata);  //释放链表

              }

   

              pEnt->close();

         }

heluyuan

本想发贴咨询一下在AutoCAD 2007.NET API中，用C＃中如何给实体设置XData扩展属性，现就此贴延续一下了，希望能把XData彻底弄清楚。

在VC60下的XData的添加方法，Autodesk公司的示例文档中有很好的代码：

void

addXdata()

{

    AcDbObject* pObj = selectObject(AcDb::kForRead);

    if (!pObj) {

        acutPrintf("Error selecting object\n");

        return;

    }

 

   

    // Get the application name and string to be added to

    // xdata.

    //

    char appName[132], resString[200];

    appName[0] = resString[0] = '\0';

 

    acedGetString(NULL, "Enter application name: ",

        appName);

    acedGetString(NULL, "Enter string to be added: ",

        resString);

 

    

    struct  resbuf  *pRb, *pTemp;

   

    pRb = pObj->xData(appName);

 

    if (pRb != NULL) {

 

        // If xdata is present, then walk to the

        // end of the list.

        //

        for (pTemp = pRb; pTemp->rbnext != NULL;

                pTemp = pTemp->rbnext)

                { ; }

    } else {

        // If xdata is not present, register the application

        // and add appName to the first resbuf in the list.

        // Notice that there is no -3 group as there is in

        // AutoLISP. This is ONLY the xdata so

        // the -3 xdata-start marker isn't needed.

        //

        acdbRegApp(appName);

 

        pRb = acutNewRb(AcDb::kDxfRegAppName);

        pTemp = pRb;

        pTemp->resval.rstring

            = (char*) malloc(strlen(appName) + 1);

        strcpy(pTemp->resval.rstring, appName);

    }

 

    // Add user-specified string to the xdata.

    //

    pTemp->rbnext = acutNewRb(AcDb::kDxfXdAsciiString);

    pTemp = pTemp->rbnext;

    pTemp->resval.rstring

        = (char*) malloc(strlen(resString) + 1);

    strcpy(pTemp->resval.rstring, resString);

 

    // The following code shows the use of upgradeOpen()

    // to change the entity from read to write.

    //

    pObj->upgradeOpen();

    pObj->setXData(pRb);

   

    pObj->close();

    acutRelRb(pRb);

}

问题是在AutoCAD 2007.NET API下：

网上现有的只是关于Xrecord的示例代码，如下：

public ObjectId createXrecord(string name,string salary,string division)

{

    Database db = HostApplicationServices.WorkingDatabase;

    Transaction trans = db.TransactionManager.StartTransaction();

    try

    {

        BlockTable bt = (BlockTable)MyT.GetObject(db.BlockTableId, OpenMode.ForWrite, false);

        BlockTableRecord br = (BlockTableRecord)MyT.GetObject(bt[BlockTableRecord.ModelSpace], OpenMode.ForWrite, false);

       

        //Create the custom per-employee data

        Xrecord xRec = new Xrecord();

        //We want to add //Name//, //Salary// and //Division// information.  Here is how:

        xRec.Data = new ResultBuffer(

            new TypedValue((int)DxfCode.Text, name),

            new TypedValue((int)DxfCode.Real, salary),

            new TypedValue((int)DxfCode.Text, division));

 

        //Next, we need to add this data to the //Extension Dictionary// of the employee.

        br.CreateExtensionDictionary();

        DBDictionary brExtDict = (DBDictionary)trans.GetObject(br.ExtensionDictionary, OpenMode.ForWrite, false);

        brExtDict.SetAt("EmployeeData", xRec); //Set our XRecord in the dictionary at //EmployeeData//.

        trans.AddNewlyCreatedDBObject(xRec, true);

        return xRec.ObjectId;

    }

    catch

    {

        return ObjectId.Null;

    }   

}

 

但为何添加XData扩展数据就会报错eBadDxfSequence呢？

public void addXData(Entity ent,string name,string salary,string division)

        {

            Database db = HostApplicationServices.WorkingDatabase;

            Transaction MyT = db.TransactionManager.StartTransaction();

            try

            {

                BlockTable bt = (BlockTable)MyT.GetObject(db.BlockTableId, OpenMode.ForWrite, false);

                BlockTableRecord btr = (BlockTableRecord)MyT.GetObject(bt[BlockTableRecord.ModelSpace], OpenMode.ForWrite, false);

                ent.XData = new ResultBuffer();

                ent.XData = new ResultBuffer(

                new TypedValue((int)DxfCode.Text, name),

                new TypedValue((int)DxfCode.Real, salary),

                new TypedValue((int)DxfCode.Text, division));

                btr.AppendEntity(ent);

                MyT.AddNewlyCreatedDBObject(ent, true);

            }

            catch

            {

            }

        }

 

后来又试过如下方法：

                    Autodesk.AutoCAD.DatabaseServices.SymbolUtilityServices.IsRegAppAcadName("name");

                    pEnt.XData = new ResultBuffer(new TypedValue((int)DxfCode.ExtendedDataRegAppName,"name"));

                    pEnt.XData.Add(new TypedValue((int)DxfCode.ExtendedDataControlString, "this is a test!"));

 

也报错……为eRegappIdNotFound，应该是因为未注册应用程序名的原因，

求教全局函数acdbRegApp(appName)在C＃中的对应方法！！

aqin

 public void AddXData()

        {

            Editor ed = Application.DocumentManager.MdiActiveDocument.Editor;

            ed.WriteMessage("添加扩充数据XDATA\n");

            PromptEntityOptions entOps = new PromptEntityOptions("选择要打开的对象\n");

            PromptEntityResult entRes;

            entRes = ed.GetEntity(entOps);

            if (entRes.Status != PromptStatus.OK)

            {

                ed.WriteMessage("选择对象失败，退出");

                return;

            }

            ObjectId objId = entRes.ObjectId;

            Database db = HostApplicationServices.WorkingDatabase;

            using (Transaction trans = db.TransactionManager.StartTransaction())

            {

                Entity ent = trans.GetObject(objId, OpenMode.ForWrite) as Entity ;

                ent.ColorIndex = 1;

                RegAppTable appTbl = trans.GetObject(db.RegAppTableId, OpenMode.ForWrite) as RegAppTable ;

                if (!appTbl.Has("MyAppName"))

                {

                    RegAppTableRecord appTblRcd = new RegAppTableRecord();

                    appTblRcd.Name = "MyAppName";

                    appTbl.Add(appTblRcd);

                    trans.AddNewlyCreatedDBObject(appTblRcd, true);

                }

                ResultBuffer resBuf = new ResultBuffer();//new TypedValue(1001, "MyAppName"), new TypedValue(1000, "开发部门"));

                resBuf.Add(new TypedValue(1001, "MyAppName"));//注册程序名称

                resBuf.Add(new TypedValue(1000 , " Hongxian Qin"));//姓名

                resBuf.Add(new TypedValue(1000 , " 工程部"));//部门

                resBuf.Add(new TypedValue(1040, 2000.0));//薪水

                ent.XData =  resBuf;

                trans.Commit();

            }

        }

aqin

        [CommandMethod("GETXDATA")]
        public void GETXDATA()
        {
            Editor ed = Application.DocumentManager.MdiActiveDocument.Editor;
            ed.WriteMessage("获取扩充数据XDATA\n");

            PromptEntityOptions entOps = new PromptEntityOptions("选择要打开的对象");
            PromptEntityResult entRes = ed.GetEntity(pr);
            if (entRes.Status != PromptStatus.OK)
            {
                ed.WriteMessage("选择对象失败，退出");
                return;
            }
            Database db = Autodesk.AutoCAD.ApplicationServices.Application.DocumentManager.MdiActiveDocument.Database;
            using (Transaction tr = db.TransactionManager.StartTransaction())
            {

                Entity ent = (Entity)tr.GetObject(res.ObjectId, OpenMode.ForRead);
                ResultBuffer resBuf = ent.XData;
                if (rb != null)
                {
                    //
                    IEnumerator iter = resBuf.GetEnumerator();
                    while (iter.MoveNext())
                    {
                        TypedValue tmpVal = (TypedValue)iter.Current;
                        ed.WriteMessage(tmpVal.TypeCode.ToString() + ":");
                        ed.WriteMessage(tmpVal.Value.ToString() + "\n");
                    }
                }
            }
        }