[求助]：图块清理(Purge)的问题

LQH

通常CAD图形中的图块，如果未被引用，可以被purge清理掉，以节省磁盘空间，但有某些块虽未被引用，我仍然需要保留在图形，不让其被清理，可何做到！

XDSoft

最初由 LQH 发布
[B]通常CAD图形中的图块，如果未被引用，可以被purge清理掉，以节省磁盘空间，但有某些块虽未被引用，我仍然需要保留在图形，不让其被清理，可何做到！ [/B]

你可以使用反应器：

2. 
   
3. AcEditorReactor::commandWillStart Function virtual void
   
4. 
   
5. commandWillStart(
   
6. 
   
7. const char* cmdStr);
   
8. 
   
9. cmdStr Passed in string of the command being executed
   
10. 
    
11. This callback function indicates that the command cmdStr is about to
    
12. 
    
13. begin execution.
    
14. 
    
15. cmdStr may be up to 257 characters (including the string terminator).
    
16. 
    

<br /> AcEditorReactor::commandWillStart Function virtual void<br /> <br /> commandWillStart(<br /> <br /> const char* cmdStr);<br /> <br /> cmdStr Passed in string of the command being executed <br /> <br /> This callback function indicates that the command cmdStr is about to <br /> <br /> begin execution.<br /> <br /> cmdStr may be up to 257 characters (including the string terminator).<br /> <br />

来判断是否执行了purge 命令，然后你保存你需要的“未被引用”的BLOCK，等AcEditorReactor::commandEnded  时候，你再恢复那些BLOCK到数据库。

具体可以看联机帮助和ARX目录下面的SAMPLE目录下的例子。

下面摘自联机帮助，介绍AcEditorReactor::commandEnded

2. 
   
3. 
   
4. AcEditorReactor::commandEnded Function virtual void
   
5. 
   
6. commandEnded(
   
7. 
   
8. const char* cmdStr);
   
9. 
   
10. cmdStr Passed in string of the command being executed
    
11. 
    
12. This callback function indicates that the command cmdStr has completed.
    
13. 
    
14. 
    
15. cmdStr may be up to 257 characters (including the string terminator).
    
16. 
    
17. 
    
18. With commands involving sets of entities, and when
    
19. AcEditorReactor::comandEnded() notification is sent, the last entity
    
20. 
    
21. operated upon is still open for read even though AutoCAD is no longer
    
22. looking at it. This prevents that entity from being opened for write via
    
23. acdbOpenObject() within the notification callback.
    
24. 
    
25. There are two ways to get around this limitation:
    
26. 
    
27. 1  The preferred method is to use a transaction to manipulate the entities
    
28. within your implementation of the commandEnded(). This bypasses any
    
29. problems opening objects that are still open.
    
30. 
    
31. Warning When using this method, you must be sure to end or terminate
    
32. 
    
33. the transaction before you return from the commandEnded() function.
    
34. 
    
35. Following is a simple example of this method:
    
36. 
    
37. void
    
38. AsdkEdReactor::commandEnded(const char *pCommand)
    
39. {
    
40.     // If AutoCAD is shutting down, then do nothing.
    
41.     //
    
42.     if (!acdbHostApplicationServices()->working Database())
    
43.         return;
    
44. 
    
45.     // get entities just operated on
    
46.     //
    
47.     ads_name sset;
    
48.     int err = acedSSGet("p", NULL, NULL, NULL, sset);
    
49.     if (err != RTNORM) {
    
50.         acutPrintf("\nError acquiring previous selection set");
    
51.         return;
    
52.     }
    
53.     actrTransactionManager->startTransaction();
    
54. 
    
55.     long length;
    
56.     acedSSLength(sset, &length);
    
57. 
    
58.     ads_name en;
    
59.     AcDbObjectId eId;
    
60.     AcDbEntity *pEnt;
    
61.     for (long i=0; i <  length; i++) {
    
62.         acedSSName(sset, i, en);
    
63. 
    
64.         Acad::ErrorStatus es = acdbGetObjectId(eId, en);
    
65.         if (es != Acad::eOk) {
    
66.             acutPrintf("\nacdbGetObjectId failed: "
    
67.                 "Entity name < %lx,%lx >, error %s.", en[0], en[1],
    
68.                 acadErrorStatusText(es));
    
69.             acedSSFree(sset);
    
70.             return;
    
71.         }
    
72.         es = actrTransactionManager->getObject((AcDbObject*&)pEnt,
    
73.             eId, AcDb::kForWrite);
    
74.         if (es == Acad::eOk) {
    
75.             pEnt->setColorIndex(1);
    
76.             pEnt->close();
    
77.         } else {
    
78.             acutPrintf("\ngetObject failed with error %s.",
    
79.                 acadErrorStatusText(es));
    
80.             actrTransactionManager->abortTransaction();
    
81.             acedSSFree(sset);
    
82.             return;
    
83.         }
    
84.     }
    
85.     actrTransactionManager->endTransaction();
    
86.     acedSSFree(sset);
    
87. }
    
88. 2  Within the commandEnded() implementation, you can open the entity
    
89. for read and then repeatedly call its close() method until its isReallyClosing
    
90. () method returns Acad::kTrue, indicating that there is now only one
    
91. reader, and then use the entity's upgradeOpen() method to upgrade the
    
92. open to AcDb::kForWrite.
    
93. 
    
94. Now the entity is in a normal open AcDb::kForWrite state, so do whatever
    
95. operations you want, followed by a call to the entity's close() or cancel()
    
96. 
    
97. .
    
98. Following is a simple example of this method:
    
99. 
    
100. void
     
101. AsdkEdReactor::commandEnded(const char *pCommand)
     
102. {
     
103.     // If AutoCAD is shutting down, then do nothing.
     
104.     //
     
105.     if (!acdbHostApplicationServices()->working Database())
     
106.         return;
     
107.    
     
108.     // get entities just operated on
     
109.     //
     
110.     ads_name sset;
     
111.     int err = acedSSGet("p", NULL, NULL, NULL, sset);
     
112.     if (err != RTNORM) {
     
113.         acutPrintf("\nError acquiring previous selection set");
     
114.         return;
     
115.     }
     
116. 
     
117.     long length;
     
118.     acedSSLength(sset, &length);
     
119. 
     
120.     ads_name en;
     
121.     AcDbObjectId eId;
     
122.     AcDbEntity *pEnt;
     
123.     for (long i=0; i < length; i++) {
     
124.         acedSSName(sset, i, en);
     
125. 
     
126.         Acad::ErrorStatus es = acdbGetObjectId(eId, en);
     
127.         if (es != Acad::eOk) {
     
128.             acutPrintf("\nacdbGetObjectId failed: "
     
129.                 "Entity name < %lx,%lx >, error %s.", en[0], en[1],
     
130.                 acadErrorStatusText(es));
     
131.             acedSSFree(sset);
     
132.             return;
     
133.         }
     
134.         es = acdbOpenObject(pEnt, eId, AcDb::kForWrite);
     
135.         if (es == Acad::eOk) {
     
136.             pEnt->setColorIndex(cindex);
     
137.             pEnt->close();
     
138.         } else if (es == Acad::eWasOpenForRead) {
     
139.             // open it for read again to get a pointer to the
     
140.             // entity and then close it repeatedly until it's
     
141.             // down to one open for read.
     
142.             //
     
143.             acdbOpenObject(pEnt, eId, AcDb::kForRead);
     
144.             do
     
145.                 pEnt->close();
     
146.             while (!pEnt->isReallyClosing());
     
147. 
     
148.             // Now that we're down to one open for read, upgrade
     
149.             // the open to kForWrite.
     
150.             //
     
151.             pEnt->upgradeOpen();
     
152. 
     
153.             // do what we want and then close
     
154.             //
     
155.             pEnt->setColorIndex(1);
     
156.             pEnt->close();
     
157.         } else {
     
158.             acutPrintf("\nacdbOpenObject failed with error %s.",
     
159.                 acadErrorStatusText(es));
     
160.             acedSSFree(sset);
     
161.             return;
     
162.         }
     
163.     }
     
164.     acedSSFree(sset);
     
165. }
     

<br /> <br /> AcEditorReactor::commandEnded Function virtual void<br /> <br /> commandEnded(<br /> <br /> const char* cmdStr);<br /> <br /> cmdStr Passed in string of the command being executed <br /> <br /> This callback function indicates that the command cmdStr has completed.<br /> <br /> <br /> cmdStr may be up to 257 characters (including the string terminator).<br /> <br /> <br /> With commands involving sets of entities, and when <br /> AcEditorReactor::comandEnded() notification is sent, the last entity <br /> <br /> operated upon is still open for read even though AutoCAD is no longer <br /> looking at it. This prevents that entity from being opened for write via <br /> acdbOpenObject() within the notification callback.<br /> <br /> There are two ways to get around this limitation:<br /> <br /> 1  The preferred method is to use a transaction to manipulate the entities <br /> within your implementation of the commandEnded(). This bypasses any <br /> problems opening objects that are still open.<br /> <br /> Warning When using this method, you must be sure to end or terminate <br /> <br /> the transaction before you return from the commandEnded() function.<br /> <br /> Following is a simple example of this method:<br /> <br /> void<br /> AsdkEdReactor::commandEnded(const char *pCommand)<br /> {<br />     // If AutoCAD is shutting down, then do nothing.<br />     //<br />     if (!acdbHostApplicationServices()->working Database())<br />         return;<br /> <br />     // get entities just operated on<br />     //<br />     ads_name sset;<br />     int err = acedSSGet("p", NULL, NULL, NULL, sset);<br />     if (err != RTNORM) {<br />         acutPrintf("\nError acquiring previous selection set");<br />         return;<br />     }<br />     actrTransactionManager->startTransaction();<br /> <br />     long length;<br />     acedSSLength(sset, &length);<br /> <br />     ads_name en;<br />     AcDbObjectId eId;<br />     AcDbEntity *pEnt;<br />     for (long i=0; i <  length; i++) {<br />         acedSSName(sset, i, en);<br /> <br />         Acad::ErrorStatus es = acdbGetObjectId(eId, en);<br />         if (es != Acad::eOk) {<br />             acutPrintf("\nacdbGetObjectId failed: "<br />                 "Entity name < %lx,%lx >, error %s.", en[0], en[1],<br />                 acadErrorStatusText(es));<br />             acedSSFree(sset);<br />             return;<br />         }<br />         es = actrTransactionManager->getObject((AcDbObject*&)pEnt,<br />             eId, AcDb::kForWrite);<br />         if (es == Acad::eOk) {<br />             pEnt->setColorIndex(1);<br />             pEnt->close();<br />         } else {<br />             acutPrintf("\ngetObject failed with error %s.",<br />                 acadErrorStatusText(es));<br />             actrTransactionManager->abortTransaction();<br />             acedSSFree(sset);<br />             return;<br />         }<br />     }<br />     actrTransactionManager->endTransaction();<br />     acedSSFree(sset);<br /> }<br /> 2  Within the commandEnded() implementation, you can open the entity <br /> for read and then repeatedly call its close() method until its isReallyClosing<br /> () method returns Acad::kTrue, indicating that there is now only one <br /> reader, and then use the entity's upgradeOpen() method to upgrade the <br /> open to AcDb::kForWrite.<br /> <br /> Now the entity is in a normal open AcDb::kForWrite state, so do whatever <br /> operations you want, followed by a call to the entity's close() or cancel()<br /> <br /> . <br /> Following is a simple example of this method:<br /> <br /> void<br /> AsdkEdReactor::commandEnded(const char *pCommand)<br /> {<br />     // If AutoCAD is shutting down, then do nothing.<br />     //<br />     if (!acdbHostApplicationServices()->working Database())<br />         return;<br />     <br />     // get entities just operated on<br />     //<br />     ads_name sset;<br />     int err = acedSSGet("p", NULL, NULL, NULL, sset);<br />     if (err != RTNORM) {<br />         acutPrintf("\nError acquiring previous selection set");<br />         return;<br />     }<br /> <br />     long length;<br />     acedSSLength(sset, &length);<br /> <br />     ads_name en;<br />     AcDbObjectId eId;<br />     AcDbEntity *pEnt;<br />     for (long i=0; i < length; i++) {<br />         acedSSName(sset, i, en);<br /> <br />         Acad::ErrorStatus es = acdbGetObjectId(eId, en);<br />         if (es != Acad::eOk) {<br />             acutPrintf("\nacdbGetObjectId failed: "<br />                 "Entity name < %lx,%lx >, error %s.", en[0], en[1],<br />                 acadErrorStatusText(es));<br />             acedSSFree(sset);<br />             return;<br />         }<br />         es = acdbOpenObject(pEnt, eId, AcDb::kForWrite);<br />         if (es == Acad::eOk) {<br />             pEnt->setColorIndex(cindex);<br />             pEnt->close();<br />         } else if (es == Acad::eWasOpenForRead) {<br />             // open it for read again to get a pointer to the<br />             // entity and then close it repeatedly until it's<br />             // down to one open for read.<br />             //<br />             acdbOpenObject(pEnt, eId, AcDb::kForRead);<br />             do<br />                 pEnt->close();<br />             while (!pEnt->isReallyClosing());<br /> <br />             // Now that we're down to one open for read, upgrade<br />             // the open to kForWrite.<br />             //<br />             pEnt->upgradeOpen();<br /> <br />             // do what we want and then close<br />             //<br />             pEnt->setColorIndex(1);<br />             pEnt->close();<br />         } else {<br />             acutPrintf("\nacdbOpenObject failed with error %s.",<br />                 acadErrorStatusText(es));<br />             acedSSFree(sset);<br />             return;<br />         }<br />     }<br />     acedSSFree(sset);<br /> }<br />