Insert an external graph block into the current graph (C # code)

In the process of using C # To develop AutoCAD tools, you need to transfer the externally defined DWG block file to the current file. On the internet, you have checked a lot of relevant materials, not many of which are involved, sort it as follows: 1 Public objectid insertblock (string filename)
2 {
3 objectid blockid;
4 // read external graph blocks from the Graphic Database
5 database blockdatabase = new database (false, true );
6 blockdatabase. readdwgfile (filename, system. Io. fileshare. Read, false, String. Empty );
7 blockdatabase. closeinput (true );
8
9 database DB = hostapplicationservices. workingdatabase;
10 using (transaction trans = dB. transactionmanager. starttransaction ())
11 {
12 blocktable bt = (blocktable) Trans. GetObject (db. blocktableid, openmode. forwrite );
13 string blockname = symbolutilityservices. getblocknamefrominsertpathname (filename );
14 // insert an external graph block into the current model space
15 blockid = dB. insert (blockname, blockdatabase, false );
16 TRANS. Commit ();
17}
18 return blockid;
19}