C++ QLabel::clear方法代码示例

int main(int argc, char ** argv) {
   QApplication app{argc, argv};
   QWidget w;
   QFormLayout layout{&w};
   QLineEdit address;
   layout.addRow("Address to look up", &address);
   QLabel result;
   layout.addRow("Result", &result);
   QPushButton lookup{"Lookup"};
   layout.addRow(&lookup);
   lookup.setDefault(true);
   w.show();

   IfLookup ifLookup;
   QObject::connect(&lookup, &QPushButton::clicked, [&]{
      result.clear();
      ifLookup.lookup(address.text());
   });
   QObject::connect(&ifLookup, &IfLookup::hasResult, [&](IfLookup::Result r){
      static const QMap<IfLookup::Result, QString> msgs = {
         { IfLookup::Local, "Local" }, { IfLookup::NonLocal, "Non-Local" },
         { IfLookup::TimedOut, "Timed Out" }, { IfLookup::Error, "Lookup Error" }
      };
      result.setText(msgs.value(r));
   });

   return app.exec();
}

void BinCalcWidget::clearButtonClicked()
{
    QLineEdit *lineEdit = findChild<QLineEdit *>();
    if( lineEdit == 0 )
        return;
    QLabel *label = findChild<QLabel *>();
    if( label == 0 )
        return;

    lineEdit->clear();
    label->clear();
    m_operator.clear();
    m_value = 0;
}

void LapTimeComparisonDialog::updateCharts()
{
    DriverData *driverData[4] = {0, 0, 0, 0};
    QString driver;
    for (int i = 0; i < 4; ++i)
    {
        int idx = eventData.getDriverId(getNumber(i));
        if (idx > 0)
        {
            driver = eventData.getDriversData()[idx-1].getDriverName();
            driverData[i] = &eventData.getDriversData()[idx-1];
//            carIdx = (eventData.getDriversData()[idx-1].getNumber() > 13 ?
//                             eventData.getDriversData()[idx-1].getNumber() - 2 :
//                             eventData.getDriversData()[idx-1].getNumber() - 1) / 2;

            QTableWidgetItem *item = ui->chartsTableWidget->item(0, i);
            item->setText(driver);
            item->setTextColor(ColorsManager::getInstance().getCarColor(driverData[i]->getNumber()));

//            if (carIdx >= 0)
            {
                QLabel *lab = qobject_cast<QLabel*>(ui->chartsTableWidget->cellWidget(1, i));
                if (!lab)
                {
                    lab = new QLabel();
                    lab->setAlignment(Qt::AlignCenter);
                    lab->setPixmap(ImagesFactory::getInstance().getCarThumbnailsFactory().getCarThumbnail(driverData[i]->getNumber(), thumbnailsSize));//eventData.carImages[carIdx].scaledToWidth(120, Qt::SmoothTransformation));
                    ui->chartsTableWidget->setCellWidget(1, i, lab);
                }
                else
                    lab->setPixmap(ImagesFactory::getInstance().getCarThumbnailsFactory().getCarThumbnail(driverData[i]->getNumber(), thumbnailsSize));//eventData.carImages[carIdx].scaledToWidth(120, Qt::SmoothTransformation));
            }
        }
        else
        {
            QTableWidgetItem *item = ui->chartsTableWidget->item(0, i);
            item->setText("");

            QLabel *lab = qobject_cast<QLabel*>(ui->chartsTableWidget->cellWidget(1, i));
            if (lab)
                lab->clear();
        }
    }
    lapCompChart->setData(driverData);
    lapCompChart->repaint();
}

void FormGame::updateTankReborn()
{
    ITank* tank = (ITank*)sender();
    int index = _tanks.indexOf(tank);

    if(index > -1)
    {
        int index_of_player = _match_players.value(index);
        QLabel* label = findChild<QLabel*>(QString("_l_time_to_reborn_%1").arg(index_of_player));
        label->clear();
        label->hide();
    }
    if(tank == _tank)
    {
        updateTankView();
    }
}

QWidget *AppAboutPage::createPage(QWidget *parent)
{
    QWidget *w = new QWidget(parent);
    QVBoxLayout *layout = new QVBoxLayout(w);
    layout->setSpacing(0);
    layout->setMargin(0);

    // Splash label
    QWidget *sw = new QWidget(w);
    QHBoxLayout *swLayout = new QHBoxLayout(sw);
    sw->setLayout(swLayout);
    QLabel *splash = new QLabel(w);
    splash->setPixmap(theme()->splashScreenPixmap(settings()->path(Core::ISettings::SplashScreen)));
    splash->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Preferred);
    swLayout->addSpacerItem(new QSpacerItem(10, 10, QSizePolicy::Expanding));
    swLayout->addWidget(splash);
    swLayout->addSpacerItem(new QSpacerItem(10, 10, QSizePolicy::Expanding));
    layout->addWidget(sw);
    QFrame *line = new QFrame(w);
    line->setFrameShape(QFrame::HLine);
    line->setFrameShadow(QFrame::Sunken);
    layout->addWidget(line);
    layout->addSpacerItem(new QSpacerItem(20, 20, QSizePolicy::Fixed, QSizePolicy::Fixed));

    // Welcome label
    QLabel *label = new QLabel(w);
    label->setWordWrap(true);
    label->setOpenExternalLinks(true);
    layout->addWidget(label);
    layout->addSpacerItem(new QSpacerItem(20,20, QSizePolicy::Expanding, QSizePolicy::Expanding));
    label->clear();
        Utils::UpdateChecker *up = Core::ICore::instance()->updateChecker();
    QString tmp = tkTr(Trans::Constants::APPLICATION_ABOUT_YEAR_1_WEB_2)
                   .arg(QDate::currentDate().year())
                   .arg(qApp->organizationDomain());
    if (up->hasUpdate()) {
        tmp.append(tkTr(Trans::Constants::UPDATE_AVAILABLE));
    } else {
        tmp.append(tkTr(Trans::Constants::VERSION_UPTODATE));
    }
    label->setText(tmp);
    return w;
}

void LapTimeComparisonDialog::show(int currentCarId)
{
//    if (comboBox[0]->itemText(1) == "")
//    {
//        comboBox[0]->addItems(SeasonData::getInstance().getDriversList());
//        comboBox[1]->addItems(SeasonData::getInstance().getDriversList());
//        comboBox[2]->addItems(SeasonData::getInstance().getDriversList());
//        comboBox[3]->addItems(SeasonData::getInstance().getDriversList());
//    }
    setCurrentDriver(currentCarId);
    for (int i = 0; i < 4; ++i)
    {
        QLabel *lab = qobject_cast<QLabel*>(ui->tableWidget->cellWidget(0, i+1));
        if (lab)
            lab->clear();
    }

    updateData();
    updateCharts();

    QDialog::show();
}

QWidget *AppAboutPage::createPage(QWidget *parent)
{
    QWidget *w = new QWidget(parent);
    QVBoxLayout *layout = new QVBoxLayout(w);
    layout->setSpacing(0);
    layout->setMargin(0);
    QLabel *label = new QLabel(w);
    label->setWordWrap(true);
    label->setOpenExternalLinks(true);
    layout->addWidget(label);
    layout->addSpacerItem(new QSpacerItem(20,20, QSizePolicy::Expanding, QSizePolicy::Expanding));
    label->clear();
    Utils::UpdateChecker *up = Core::ICore::instance()->updateChecker();
    QString tmp = tr(ABOUT_TEXT).arg(qApp->applicationName(), qApp->organizationDomain()).arg(QDate::currentDate().year());
    if (up->hasUpdate()) {
        tmp.append("<br /><br />" + tkTr(Trans::Constants::UPDATE_AVAILABLE));
    } else {
        tmp.append("<br /><br />" + tkTr(Trans::Constants::VERSION_UPTODATE));
    }
    label->setText(tmp);
    return w;
}

/**
 * 五组原图显示函数
 */
bool ImageViewer::updateImages()
{
    if (!hasinitmodel)
        return false;

    QString tmpcamid;
    bool ret = true;
    QString tmpcamimgdir;

    QLabel * tmpcamimg1 = NULL;
    QLabel * tmpcamimg2 = NULL;
    QLabel * tmpcamimg3 = NULL;
    QLabel * tmpcamimg4 = NULL;
    QLabel * tmpcamimg5 = NULL;
    QLabel * tmpcamimg = NULL;
    tmphasfc1 = false;
    tmphasfc2 = false;
    tmphasfc3 = false;
    tmphasfc4 = false;
    tmphasfc5 = false;

    for (int i = 0; i < 5; i++)
    {
        switch (i)
        {
            case 0: tmpcamid = ui->cam1->currentText(); 
                tmpcamimg1 = ui->cam1img1;
                tmpcamimg2 = ui->cam1img2;
                tmpcamimg3 = ui->cam1img3;
                tmpcamimg4 = ui->cam1img4;
                tmpcamimg5 = ui->cam1img5;
                break;
            case 1: tmpcamid = ui->cam2->currentText(); 
                tmpcamimg1 = ui->cam2img1;
                tmpcamimg2 = ui->cam2img2;
                tmpcamimg3 = ui->cam2img3;
                tmpcamimg4 = ui->cam2img4;
                tmpcamimg5 = ui->cam2img5;
                break;
            case 2: tmpcamid = ui->cam3->currentText(); 
                tmpcamimg1 = ui->cam3img1;
                tmpcamimg2 = ui->cam3img2;
                tmpcamimg3 = ui->cam3img3;
                tmpcamimg4 = ui->cam3img4;
                tmpcamimg5 = ui->cam3img5;
                break;
            case 3: tmpcamid = ui->cam4->currentText(); 
                tmpcamimg1 = ui->cam4img1;
                tmpcamimg2 = ui->cam4img2;
                tmpcamimg3 = ui->cam4img3;
                tmpcamimg4 = ui->cam4img4;
                tmpcamimg5 = ui->cam4img5;
                break;
            case 4: tmpcamid = ui->cam5->currentText(); 
                tmpcamimg1 = ui->cam5img1;
                tmpcamimg2 = ui->cam5img2;
                tmpcamimg3 = ui->cam5img3;
                tmpcamimg4 = ui->cam5img4;
                tmpcamimg5 = ui->cam5img5;
                break;
            default:break;
        }

        __int64 & tmpcurrentfc = getTmpCurrentfc(i);

        if (tmpcamid.trimmed().compare("") == 0)
        {
            tmpcamimg1->clear();
            tmpcamimg2->clear();
            tmpcamimg3->clear();
            tmpcamimg4->clear();
            tmpcamimg5->clear();
            continue;
        }
        tmpcamimgdir = currenttmpimgpath + "_" + tmpcamid + "/";

        // 每个相机的5张图
        for (int j = -2; j < 3; j++)
        {
            switch (j)
            {
                case -2: tmpcamimg = tmpcamimg1; break;
                case -1: tmpcamimg = tmpcamimg2; break;
                case 0: tmpcamimg = tmpcamimg3; break;
                case 1: tmpcamimg = tmpcamimg4; break;
                case 2: tmpcamimg = tmpcamimg5; break;
                default:break;
            }

            QString filename3 = (QString("%1/%2.jpg").arg(tmpcamimgdir).arg(tmpcurrentfc + j));
            if (!QFile(filename3).exists())
            {
                // 清空显示
                tmpcamimg->clear();
                qDebug() << QObject::tr("图片目录：") << filename3 << QObject::tr("不存在！");

                ret = false;
//.........这里部分代码省略.........

void LapTimeComparisonDialog::updateData()
{
    int scrollBarPosition = ui->tableWidget->verticalScrollBar()->sliderPosition();

    QItemSelectionModel * selection = ui->tableWidget->selectionModel();
//    for (int i = ui->tableWidget->rowCount()-1; i >= 0; --i)
//        ui->tableWidget->removeRow(i);

    QTableWidgetItem *item;

    int firstLap = 99, lastLap = 0;
    int index[4];

    QString wTitle = "Lap time comparison: ";
    for (int i = 0; i < 4; ++i)
    {
        index[i] = 0;
        int idx = eventData.getDriverId(getNumber(i));
        if (idx > 0)
        {
            if (i > 0)
                wTitle += " - ";
            wTitle += eventData.getDriversData()[idx-1].getDriverName();
            if(!eventData.getDriversData()[idx-1].getLapData().isEmpty())
            {
                if (eventData.getDriversData()[idx-1].getLapData()[0].getLapNumber() < firstLap)
                    firstLap = eventData.getDriversData()[idx-1].getLapData()[0].getLapNumber();

                if (eventData.getDriversData()[idx-1].getLapData().last().getLapNumber() > lastLap)
                    lastLap = eventData.getDriversData()[idx-1].getLapData().last().getLapNumber();
            }

            DriverData &dd = eventData.getDriversData()[idx-1];
			QLabel *lab = qobject_cast<QLabel*>(ui->tableWidget->cellWidget(0, i+1));
            lab->setPixmap(ImagesFactory::getInstance().getCarThumbnailsFactory().getCarThumbnail(dd.getNumber(), thumbnailsSize));//eventData.carImages[idx].scaledToWidth(120, Qt::SmoothTransformation));
        }
        else
        {
        	QLabel *lab = qobject_cast<QLabel*>(ui->tableWidget->cellWidget(0, i+1));
        	lab->clear();
        }
    }
    setWindowTitle(wTitle);

//    ui->tableWidget->insertRow(0);
//    ui->tableWidget->setRowHeight(0, 50);

    int j = 0, k = firstLap;
    for (; k <= lastLap; ++k, ++j)
    {
        int lapNo = lastLap - k + firstLap;
        LapTime laps[4];

        if (ui->tableWidget->rowCount() <= j+1)
            ui->tableWidget->insertRow(j+1);

        item = ui->tableWidget->item(j+1, 0);
        if (!item)
        {
            item = new QTableWidgetItem(QString("%1.").arg(lapNo));
//                item->setFlags(Qt::ItemIsSelectable);
            item->setTextAlignment(Qt::AlignRight | Qt::AlignVCenter);
            item->setTextColor(ColorsManager::getInstance().getColor(LTPackets::DEFAULT));
            ui->tableWidget->setItem(j+1, 0, item);
        }
        else
            item->setText(QString("%1.").arg(lapNo));


        for (int i = 0; i < 4; ++i)
        {
            int idx = eventData.getDriverId(getNumber(i));

            if (idx > 0 && !eventData.getDriversData()[idx-1].getLapData().isEmpty())
            {
                //int lapIndex = (reversedOrder ? eventData.driversData[idx-1].lapData.size() - index[i] - 1 : index[i]);
                DriverData &dd = eventData.getDriversData()[idx-1];
                LapData ld = dd.getLapData(lapNo);

//                if (j == 0)
//                {
//                    int idx = (dd.number > 13 ? dd.number-2 : dd.number-1) / 2;
//                    QLabel *lab = qobject_cast<QLabel*>(ui->tableWidget->cellWidget(0, i+1));
//                    lab->setPixmap(smallCarImg[idx]);//eventData.carImages[idx].scaledToWidth(120, Qt::SmoothTransformation));
//                }

                if (dd.getLapData().size() > index[i] && ld.getLapNumber() == lapNo && ld.getCarID() != -1)
                {
                    laps[i] = ld.getTime();

                    item = ui->tableWidget->item(j+1, i+1);
                    if (!item)
                    {
                        item = new QTableWidgetItem(ld.getTime());
                        item->setTextAlignment(Qt::AlignCenter);
                        ui->tableWidget->setItem(j+1, i+1, item);
                    }
                    else
                        item->setText(ld.getTime());

//.........这里部分代码省略.........

//.........这里部分代码省略.........
	meth->addItem("sha512");
	meth->setToolTip(Window::tr("Hashing method"));
	meth->setCurrentText(settings.value("HashingMethod", "md5").toString());
	QObject::connect(&window, &Window::idle, meth, &QWidget::setEnabled);

	QObject::connect(meth, &QComboBox::currentTextChanged,
		[&](const QString &text) { settings.setValue("HashingMethod", text); });

	/* toolbar */
	QHBoxLayout *pane = new QHBoxLayout;
	pane->addWidget(hash, 0, Qt::AlignLeft);
	pane->addWidget(stack);
	pane->addWidget(meth, 0, Qt::AlignRight);

	/* main layout */
	QVBoxLayout *layout = new QVBoxLayout;
	layout->addWidget(text);
	layout->addLayout(pane);

	/* the window */
	window.centralWidget()->setLayout(layout);
	window.show();

	/* future hashing */
	QFutureWatcher<Vals> zu;
	QObject::connect(&zu, &QFutureWatcher<Vals>::finished,
		[&]() {
			Vals valsi = zu.future().result();
			window.idle(true);
			if (valsi.path == "") {
				error->setText(QString::fromStdString(valsi.name));
				hash->setChecked(false);
			} else {
				error->clear();
				vals += valsi;
				test->textChanged(test->text());
			}
		});

	QObject::connect(meth, &QComboBox::currentTextChanged,
		[&](const QString &text) { if (vals.name != "") {
			window.idle(false);
			zu.setFuture(QtConcurrent::run(&update, text, vals));
		}});

	QObject::connect(&window, &Window::fileDroped,
		[&](const QString &name, const QString &path) {
			window.idle(false);
			zu.setFuture(QtConcurrent::run(&update, meth->currentText(), Vals(name, path)));
		});

	/* hashing info */
	QGraphicsBlurEffect blur;
	blur.setBlurHints(QGraphicsBlurEffect::AnimationHint);

	QPropertyAnimation anim(&blur, "blurRadius");
	anim.setDuration(2000);
	anim.setLoopCount(-1);
	anim.setKeyValueAt(0, 0);
	anim.setKeyValueAt(0.5, 3);
	anim.setKeyValueAt(1, 0);

	QLabel *hashing = new QLabel;
	hashing->setPixmap(QPixmap(":/icon"));
	hashing->setAttribute(Qt::WA_TransparentForMouseEvents);
	hashing->setGraphicsEffect(&blur);