# Qt 读写 ini
QSettings setting(ini_path, QSettings::IniFormat);
// 读
int value = setting.value("R/lower").toInt(); // 无文件或者无字段不报错，值为0
// 写
settings.setValue("General/Age", 30);

# Qt 获取当前 exe 路径
QString exe_path = QCoreApplication::applicationDirPath();
QDir dir(exe_path);
QString ini_path = dir.absoluteFilePath("ImageProcess.ini");

# Qt 选择文件夹
QFileDialog::getExistingDirectory(parent, u8"选择文件夹", QDir::homePath());

# Qt 确认对话框
QMessageBox questionBox(parent);
questionBox.setText(content);
questionBox.setWindowTitle(title);
questionBox.setIcon(QMessageBox::Question);
questionBox.setStandardButtons(QMessageBox::Yes | QMessageBox::No);
int result = questionBox.exec();
if (result != QMessageBox::Yes) {
	return false;
} else {
	return true;
}

# Qt 消息提示
QMessageBox::information(parent, u8"提示", infomation);

# windows 获取CPU逻辑处理器数量
SYSTEM_INFO sysInfo;
GetSystemInfo(&sysInfo);
int numCores = sysInfo.dwNumberOfProcessors;

# Qt QImage 和 opencv 的转换
cv::Mat image_ = cv::imread(path);
cv::cvtColor(image_, image_, cv::COLOR_BGR2RGB);
QImage(image_.data, image_.cols, image_.rows, image_.step, QImage::Format_RGB888);

# Qt 遍历文件
QStringList files = dir.entryList(QDir::Files);

# Qt 读写 txt
QFile file(list_file);
if (!file.open(QIODevice::ReadOnly | QIODevice::Text)) {
	message(this, u8"打开文件" + list_file + u8"失败");
	return;
}
QTextStream in(&file);
QString tmp;
while (!in.atEnd()) {
	in >> tmp;
}
file.close();

# opencv 调节亮度
image_.convertTo(image_, -1, 1, light);

# C++ 统计运行时间
auto start = std::chrono::high_resolution_clock::now();
auto end = std::chrono::high_resolution_clock::now();
auto duration = std::chrono::duration_cast<std::chrono::seconds>(end - start);
int time = duration.count();

# opencv 更改 RGB 值
std::vector<cv::Mat> channels;
cv::split(img, channels);
channels[0] += r;
channels[1] += g;
channels[2] += b;
cv::merge(channels, img);

# Qt 限制 QLineEdit 输入整数
QIntValidator* valid = new QIntValidator(this);
valid->setRange(1, INT_MAX);
ui.edPicNo->setValidator(valid);

# Qt 窗口变化事件
bool MainWidget::event(QEvent * ev)
{
	if (ev->type() == QEvent::Resize) {
		
	}
	return QWidget::event(ev);
}

# Qt QLabel 显示图片
QImage img = img.scaled(w, h, Qt::KeepAspectRatio);
ui.label->setPixmap(QPixmap::fromImage(img));
ui.label->show();