QT 开发经验汇总（持续更新中）

断开某对信号槽的connect

QMetaObject::Connection conn;
conn = connect(this,&TcpSocket::readyRead,this,&TcpSocket::readData);
disconnect(conn);

查找本窗口的子控件

QList<QLabel*> labelList = findChildren<QLabel*>();

QLabel * label = findChild<QLabel *>("label_username");

获取各种路径

#include <QtCore/QCoreApplication>
#include <QDebug>
#include <QDir>
#include <QStandardPaths>

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

	//获取程序所在路径
	QString applicationDirPath = QCoreApplication::applicationDirPath();
	qDebug() << "applicationDirPath=" << applicationDirPath;

	//程序的完整路径
	QString applicationFilePath = qApp->applicationFilePath();
	qDebug() << "applicationFilePath=" << applicationFilePath;

	//当前工作目录
	QString currentPath = QDir::currentPath();
	qDebug() << "currentPath=" << currentPath;

	//用户目录路径
	QString HomeLocation = QStandardPaths::writableLocation(QStandardPaths::HomeLocation);
	qDebug() << "HomeLocation=" << HomeLocation;

	QStringList HomeLocation2 = QStandardPaths::standardLocations(QStandardPaths::HomeLocation);
	qDebug() << "HomeLocation2=" << HomeLocation2[0];

	//我的文档路径
	QString DocumentsLocation = QStandardPaths::writableLocation(QStandardPaths::DocumentsLocation);
	qDebug() << "DocumentsLocation=" << DocumentsLocation;

	QStringList DocumentsLocation2 = QStandardPaths::standardLocations(QStandardPaths::DocumentsLocation);
	qDebug() << "DocumentsLocation2=" << DocumentsLocation2[0];

	//桌面路径
	QString DesktopLocation = QStandardPaths::writableLocation(QStandardPaths::DesktopLocation);
	qDebug() << "DesktopLocation=" << DesktopLocation;

	QStringList DesktopLocation2 = QStandardPaths::standardLocations(QStandardPaths::DesktopLocation);
	qDebug() << "DesktopLocation2=" << DesktopLocation2[0];

	//程序数据存放路径
	QString AppDataLocation = QStandardPaths::writableLocation(QStandardPaths::AppDataLocation);
	qDebug() << "AppDataLocation=" << AppDataLocation;

	QStringList AppDataLocation2 = QStandardPaths::standardLocations(QStandardPaths::AppDataLocation);
	qDebug() << "AppDataLocation2=" << AppDataLocation2[0];

	/*Qt5.5 中引入了另一种方法*/
	QString AppConfigLocation = QStandardPaths::writableLocation(QStandardPaths::AppConfigLocation);
	qDebug() << "AppConfigLocation=" << AppConfigLocation;

	QStringList AppConfigLocation2 = QStandardPaths::standardLocations(QStandardPaths::AppConfigLocation);
	qDebug() << "AppConfigLocation2=" << AppConfigLocation2[0];

	//临时文件路径
	QString TempLocation = QStandardPaths::writableLocation(QStandardPaths::TempLocation);
	qDebug() << "TempLocation=" << TempLocation;

	QStringList TempLocation2 = QStandardPaths::standardLocations(QStandardPaths::TempLocation);
	qDebug() << "TempLocation2=" << TempLocation2[0];

	//更传统的方法是利用QDir的一个静态函数tempPath()
	QString tempPath  = QDir::tempPath();
	qDebug() << "tempPath=" << tempPath;

	system("pause");
    return a.exec();
}

以上的输出结果：

applicationDirPath= "C:/Users/Administrator/Desktop/QtPathsTest/Debug"
applicationFilePath= "C:/Users/Administrator/Desktop/QtPathsTest/Debug/QtPathsTest.exe"
currentPath= "C:/Users/Administrator/Desktop/QtPathsTest/QtPathsTest"
HomeLocation= "C:/Users/Administrator"
HomeLocation2= "C:/Users/Administrator"
DocumentsLocation= "C:/Users/Administrator/Documents"
DocumentsLocation2= "C:/Users/Administrator/Documents"
DesktopLocation= "C:/Users/Administrator/Desktop"
DesktopLocation2= "C:/Users/Administrator/Desktop"
AppDataLocation= "C:/Users/Administrator/AppData/Roaming/QtPathsTest"
AppDataLocation2= "C:/Users/Administrator/AppData/Roaming/QtPathsTest"
AppConfigLocation= "C:/Users/Administrator/AppData/Local/QtPathsTest"
AppConfigLocation2= "C:/Users/Administrator/AppData/Local/QtPathsTest"
TempLocation= "C:/Users/Administrator/AppData/Local/Temp"
TempLocation2= "C:/Users/Administrator/AppData/Local/Temp"
tempPath= "C:/Users/Administrator/AppData/Local/Temp"

获取指定文件夹下所有文件

	// 获取所有文件名
	QDir dir(FolderPath);
	FolderPath= dir.fromNativeSeparators(FolderPath);//  "\\"转为"/" 
	if (!dir.exists()) mImgNames = QStringList("");
	dir.setFilter(QDir::Files);
	dir.setSorting(QDir::Name);
	dir.setNameFilters(QString("*.tiff;*.tif").split(";"));
	mImgNames = dir.entryList();
	for (int i = 0; i < mImgNames.size(); ++i)
	{
		qDebug() << "entryList: " << i << "-" << FolderPath+ "/" +mImgNames[i];
	}

获取指定文件夹下所有文件夹

	// 获取所有文件夹名
	QDir dir(FolderPath);
	mFolderPath = dir.fromNativeSeparators(FolderPath);//  "\\"转为"/" 
	if (!dir.exists()) mImgNames = QStringList("");
	dir.setFilter(QDir::Dirs | QDir::NoDotAndDotDot);
	dir.setSorting(QDir::Name);
	mImgNames = dir.entryList();
	for (int i = 0; i < mImgNames.size(); ++i)
	{
		qDebug() << "entryList: " << i << "-" << FolderPath + "/" +mImgNames[i];
	}