QTextEdit 自动滚屏

//msndialog.h

class MsnDialog : public QDialog
{
    Q_OBJECT
public:
    MsnDialog(QWidget *parent = 0);
private slots:
    void autoScroll();
private:
    QTextEdit *outputTextEdit; 

};

//msndialog.cpp

MsnDialog::MsnDialog(QWidget *parent) : QDialog(parent)

{

   // .......

   connect(outputTextEdit,SIGNAL(textChanged()),this,SLOT(autoScroll()) );

   // ........

}

void MsnDialog::autoScroll()
{
    QTextCursor cursor = outputTextEdit->textCursor();
    cursor.movePosition(QTextCursor::End);
    outputTextEdit->setTextCursor(cursor);
}