// 禁用的两种方式
ui->qPushButton->setDisabled(true);
ui->qPushButton->setEnabled(false);

// 启用的两种方式
ui->qPushButton->setEnabled(true);
ui->qPushButton->setDisabled(false);

QLabel *label = new QLabel("显示的文本", parent);

label->setText("文本");
label->setText("第一行\n第二行");
label->setText("<b>加粗文本</b><br><i>斜体文本</i>");

QString text = label->text();

QPixmap pixmap("路径/图像.png");
label->setPixmap(pixmap);

label->setAlignment(Qt::AlignCenter);

label->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);

QLineEdit *lineEdit = new QLineEdit(parent);

QString = lineEdit->text();

lineEdit->setText(QString)

QTextEdit *textEdit = new QTextEdit(parent);

QString = ui->qTextEdit->toHtml();

QString = ui->qTextEdit->toPlainText();

textEdit->setText(QString);

QPlainTextEdit *plainTextEdit = new QPlainTextEdit(parent);

QString = ui->qPlainTextEdit->toPlainText();

ui->qPlainTextEdit->setPlainText(QString);

int = ui->qComboBox->currentIndex();

QString = ui->qComboBox->currentText();

QVariant = ui->qComboBox->currentData();

ui->qComBox->addItem("Option 1", QVariant(1));

bool = ui->qCheckBox->isChecked();

ui->qCheckBox->setChecked(true);