C/C++ -- Gui编程 -- Qt库的使用 -- 纯代码实现信号槽

失败，系统找不着槽

 #include<QtGui>
 int main(int argc, char * argv[])
 {
     QApplication app(argc, argv);
     QTextCodec::setCodecForCStrings(QTextCodec::codecForName("utf-8"));
     QWidget wgt;
     wgt.setWindowTitle(QString::QString("我也有依靠"));
     wgt.setGeometry(, , , );
     QLabel lbl(&wgt);
     lbl.setText(QString::QString("我有依靠"));
     lbl.move(,);
     QLabel lblAlone;
     lblAlone.setText("独行侠");
     lblAlone.setGeometry(, , , );
     wgt.show();
     lblAlone.show();
     app.exec();
     ;
 }

调试开始

Object::connect: No such slot QWidget::onBtn()

调试结束