Qt单例模式

sqliteDate.h

ifndef SQLITEDATA_H

define SQLITEDATA_H

class sqliteData : public QObject
{
Q_OBJECT
public:
static sqliteData* Instance();

static void Destroy();

private:
static sqliteData* _instance;//静态成员，保存对象的唯一实例
protected:
explicit sqliteData(QObject *parent = 0);

};

endif // SQLITEDATA_H

sqlitedate.cpp

include “sqliteData.h”

sqliteData::sqliteData(QObject *parent) : QObject(parent)
{

}
sqliteData* sqliteData::_instance;
sqliteData* sqliteData::Instance(){
QMutex mutex;
if (_instance == NULL)
{
mutex.lock();
if (_instance == NULL)
{
_instance = new sqliteData();
}
mutex.unlock();
}
return _instance;
}
void sqliteData::Destroy()
{
delete _ins