[Qt-interest] A error about QLabel::setText(const QString &) ?

[Kermit Mei]

Hello! In my widget I defined the following method, and all the label_** in
it is the type of QLabel.


void ResultWidget::setInfo(const QString &str11,const QString &str12,
              const QString &str21,const QString &str22,
              const QString &str31,const QString &str32) {
  label_11->setText(str11);
  label_12->setText(str12);

  label_21->setText(str21);
  label_22->setText(str22);

  label_31->setText(str31);
  label_32->setText(str32);

}

After make the project, everything goes well, but when I run it, the program
broke down here. The gdb output is:

Program received signal SIGSEGV, Segmentation fault.
QLabel::setText (this=0x0, text=@0xbfc70874) at widgets/qlabel.h:155
155    widgets/qlabel.h: No such file or directory.
    in widgets/qlabel.h


And the stack of the program are:
(gdb) bt
#0  QLabel::setText (this=0x0, text=@0xbfc70874) at widgets/qlabel.h:155
#1  0xb7f28e7f in ResultWidget::setInfo (this=0x80c7368, str11=@0xbfc70874,
    str12=@0xbfc70870, str21=@0xbfc7086c, str22=@0xbfc70868,
    str31=@0xbfc70864, str32=@0xbfc70860)
    at /home/kermit/Project/QFreeRecite/src/gui/ResultWidget.cpp:20
... ...

I don't know why this takes errors. All the arguments I put into the arglist
is standard QString type.

What may cause it?

Thanks.
Kermit Mei