Qt简单文本编辑器，怎么了？

Question

I'm learning Qt basics using their text editor tutorial .

I can't figure out what's wrong with my code in main(). I'm having the following errors:

linker command failed with exit code 1 (use -v to see invocation)

symbol(s) not found for architecture x86_64

Here's my code:

class TextEditor : public QWidget
{
    Q_OBJECT

public:
    TextEditor();

private slots:
    void quit();

private:
    QTextEdit *textEdit;
    QPushButton *quitButton;
};

TextEditor::TextEditor()
{
    textEdit = new QTextEdit;
    quitButton = new QPushButton(tr("Quit"));

    connect(quitButton, SIGNAL(clicked()), this, SLOT(quit()));

    QVBoxLayout *layout = new QVBoxLayout;
    layout->addWidget(textEdit);
    layout->addWidget(quitButton);

    setLayout(layout);

    setWindowTitle(tr("TextEditor"));
}

void TextEditor::quit()
{
    QMessageBox messageBox;
    messageBox.setWindowTitle(tr("TextEditor"));
    messageBox.setText(tr("Really?"));
    messageBox.setStandardButtons(QMessageBox::Yes | QMessageBox::No);
    messageBox.setDefaultButton(QMessageBox::No);
    if (messageBox.exec() == QMessageBox::Yes)
        qApp->quit();
}

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

    TextEditor w;
    w.show();

    return app.exec();
}

Answer 1

add following to the bottom of the source file.

#include "main.moc"

Then do build->run qmake and then build->rebuild