保存

void Widget::on_savebtn_clicked()
{
    QString filename = QFileDialog::getSaveFileName(this, "保存", "C:/Users/yc/Desktop/", "图片 (*.png *.xpm *.jpg);;文本 (*.txt);;所有文件 (*.*)");
    if(filename.isNull()){
        QMessageBox::information(this, "提示", "取消保存");
        return ;
    }
    QFile file(filename);
    if(!file.open(QFile::ReadWrite)){
        return ;
    }
    QString msg = ui->textEdit->toPlainText();
    file.write(msg.toLatin1());
    file.close();
}

移动

//键盘按下事件的处理函数的定义
void Widget::keyPressEvent(QKeyEvent *event)
{
    //qDebug() << "键盘按下" << event->text() << "键值为" << event -> key();
    switch(event->key()){

    case 'W':if(ui->label->y() <= 0-ui->label->height()){
                ui->label->move(ui->label->x(), this->height());
            }
            ui -> label -> move(ui->label->x(), ui->label->y()-1);break;
    case 'S':if(ui->label->y() >= this->height()){
                ui->label->move(ui->label->x(), 0-ui->label->height());
            }
            ui -> label -> move(ui->label->x(), ui->label->y()+1);break;
    case 'A':if(ui->label->x() <= 0-ui->label->width()){
                ui->label->move(this->width(), ui->label->height());
            }
            ui -> label -> move(ui->label->x()-1, ui->label->y());break;
    case 'D':if(ui->label->x() >= this->width()){
                ui->label->move(0-ui->label->width(), ui->label->y());
            }
            ui -> label -> move(ui->label->x()+1, ui->label->y());break;
    }
}