Problems with including QWebView in QT application

I am using qt creator. I wanted to show a webpage inside QWebView, but my projet doesn't compile. When i want to inc开发者_如何学JAVAlude QWebView, editor says "no such file or directory". My code:

#include <QApplication>
#include <QUrl>
#include <QWebView>


int main(int argc, char *argv[])
 {
QApplication a(argc, argv);

QWebView view;
view.showMaximized();

return a.exec();

}

Did you add in your Project_name.pro file in Qt Creator line like this: QT += core gui webkit ?