Qt customizes qdebug () Information to the log file

Http://wan-2004.iteye.com/blog/888963

Qt hasQinstallmsghandlerThe method can be used to customize the callback function after a message is generated. The callback function also has the qdebug level information. In this way, we can easily customize error messages to our own log files.

As follows:

CPP Code

1. # Include <qtdebug>
2. # Include <qfile>
3. # Include <qtextstream>
4. // The callback function implements debugging information to the file.
5. Void custommessagehandler (qtmsgtype type, const char * MSG)
6. {
7. Qstring txt;
8. Switch (type ){
9. Case qtdebugmsg:
10. TXT = qstring ("Debug: % 1"). Arg (MSG );
11. Break;
13. Case qtwarningmsg:
14. TXT = qstring ("Warning: % 1"). Arg (MSG );
15. Break;
16. Case qtcriticalmsg:
17. TXT = qstring ("critical: % 1"). Arg (MSG );
18. Break;
19. Case qtfatalmsg:
20. TXT = qstring ("Fatal: % 1"). Arg (MSG );
21. Abort ();
22. }
24. Qfile OUTFILE ("Debug. log ");
25. OUTFILE. Open (qiodevice: writeonly | qiodevice: append );
26. Qtextstream TS (& OUTFILE );
27. TS <TXT <Endl;
28. }
30. Int main (INT argc, char * argv [])
31. {
32. Qapplication app (argc, argv );
34. // Register the callback function using this method
35. Qinstallmsghandler (custommessagehandler );
36. ...
37. Return app.exe C ();
38. }