setText translation

1.I create a QTreeWidgetItem

Code:

---

QTreeWidgetItem *cities = new QTreeWidgetItem(this);
     cities->setText(0, tr("Cities"));

---

and use lupdate and linguist to translate "Cities" into other languages.but it can not ,and "Cities" still exist.Why?
By the way,I create a Menu,

Code:

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fileMenu = menuBar()->addMenu(tr("&File"));

---

and the program can do translation.

What steps did you take? Did you actually install a translator?

What I have done as follows:
1. add TRANSLATIONS = hellotr_la.ts to the xxx.pro
2.lupdate –verbose xxxx.pro
3.Linguist hellotr_la.ts translate what need to,and release the file
4.compile and run my program.

Yes, but in your program. Do you install a translator as explained in the Internationalization with Qt document?

I think I have done,the following is my code in main function

Code:

---

main()
{
...
 QTranslator appTranslator;
 appTranslator.load("coin3dtr_la");
 QApplication::installTranslator(&appTranslator);
...
}

---

By the way,I create a Menu,

Code:

---

fileMenu = menuBar()->addMenu(tr("&File"));

---

and the program can does translation.