QT implements the delete method of the container

Summary of premises

When writing interface , You cannot avoid using the same type repeatedly , And you only need to use it once , No further application . When we finish using a container , Or when you need to empty a container, you need to delete the contents one by one . If you write directly in the interface QCheckBox *box=new QCheckBox(this); Instead of delete, It is easy to cause memory leakage .  So we store it in vector in , We can delete it all by traversing in the destructor , This can not only simplify our memory management work , Reduce the risk of memory leaks .

vector  advantage

• He can store at will , It has unlimited advantages .

• After deleting a certain data in the middle , Subsequent data will be automatically supplemented , No waste .

delete  Method 1 of container ：

for (std::vector<QCheckBox*>::iterator itvet = m_vetAddCheckBoxControls.begin(); itvet != m_vetAddCheckBoxControls.end(); itvet++)
{
 if(*itvet)
 {
 delete *itvet;
 *itvet = nullptr;
 }

 }
 m_vetAddCheckBoxControls.clear();


The most traditional way , You can do this in the destructor , It traverses , Delete every item of data in the container , Finally, just in case , The container clear().

delete  Method 2 of container ：

vector<QCheckBox*>().swap(m_vetAddCheckBoxControls);


This method is not only applicable to vector, The same applies to QMAp, Only need to vector<QCheckBox*>() Replace with QMap<QCheckBox*,bool>() That's all right. .

This method can be interspersed in the code , It does not affect the later use .

summary

These two methods cannot be used at the same time , Only one of the two , When I first used the second method, I still kept the first method in the destructor . As a result, errors are always reported when closing the interface and no solution can be found . This is also a big hole I stepped into . Both methods have their own advantages , You can choose to use it according to your own situation . The first one is applicable to emptying processing that does not need to be used during program operation , The second is more appropriate .

This is the end of today's update , I hope you guys will criticize and correct ！