Question

这是从qt ui文件生成的代码，我看到代码使用new关键字来分配内存但是类中没有delete关键字来删除已分配的资源，这是来自qt开发人员的错误还是还有别的东西（没有解除分配的资源）？

/********************************************************************************
** Form generated from reading UI file 'canyyeffectcontrol.ui'
**
** Created by: Qt User Interface Compiler version 5.0.2
**
** WARNING! All changes made in this file will be lost when recompiling UI file!
********************************************************************************/

#ifndef UI_CANYYEFFECTCONTROL_H
#define UI_CANYYEFFECTCONTROL_H

#include <QtCore/QVariant>
#include <QtWidgets/QAction>
#include <QtWidgets/QApplication>
#include <QtWidgets/QButtonGroup>
#include <QtWidgets/QCheckBox>
#include <QtWidgets/QGridLayout>
#include <QtWidgets/QHeaderView>
#include <QtWidgets/QLabel>
#include <QtWidgets/QSlider>
#include <QtWidgets/QSpinBox>
#include <QtWidgets/QWidget>

QT_BEGIN_NAMESPACE

class Ui_canyyeffectcontrol
{
public:
    QGridLayout *gridLayout;
    QSlider *Threshold2Slider;
    QLabel *Threshold1Label;
    QLabel *ApertureSizeLabel;
    QLabel *Threshold2Label;
    QSpinBox *Threshold1Spin;
    QSpinBox *Threshold2Spin;
    QSpinBox *ApertureSizeSpin;
    QSlider *ApertureSizeSlider;
    QSlider *Threshold1Slider;
    QCheckBox *EL2GLabel;

    void setupUi(QWidget *canyyeffectcontrol)
    {
        if (canyyeffectcontrol->objectName().isEmpty())
            canyyeffectcontrol->setObjectName(QStringLiteral("canyyeffectcontrol"));
        canyyeffectcontrol->resize(432, 210);
        canyyeffectcontrol->setMinimumSize(QSize(153, 119));
        canyyeffectcontrol->setMaximumSize(QSize(432, 210));
        gridLayout = new QGridLayout(canyyeffectcontrol);
        gridLayout->setObjectName(QStringLiteral("gridLayout"));
        Threshold2Slider = new QSlider(canyyeffectcontrol);
        Threshold2Slider->setObjectName(QStringLiteral("Threshold2Slider"));
        Threshold2Slider->setOrientation(Qt::Horizontal);

        gridLayout->addWidget(Threshold2Slider, 4, 1, 1, 2);

        Threshold1Label = new QLabel(canyyeffectcontrol);
        Threshold1Label->setObjectName(QStringLiteral("Threshold1Label"));

        gridLayout->addWidget(Threshold1Label, 2, 0, 1, 1);

        ApertureSizeLabel = new QLabel(canyyeffectcontrol);
        ApertureSizeLabel->setObjectName(QStringLiteral("ApertureSizeLabel"));

        gridLayout->addWidget(ApertureSizeLabel, 5, 0, 1, 1);

        Threshold2Label = new QLabel(canyyeffectcontrol);
        Threshold2Label->setObjectName(QStringLiteral("Threshold2Label"));

        gridLayout->addWidget(Threshold2Label, 4, 0, 1, 1);

        Threshold1Spin = new QSpinBox(canyyeffectcontrol);
        Threshold1Spin->setObjectName(QStringLiteral("Threshold1Spin"));

        gridLayout->addWidget(Threshold1Spin, 2, 3, 1, 1);

        Threshold2Spin = new QSpinBox(canyyeffectcontrol);
        Threshold2Spin->setObjectName(QStringLiteral("Threshold2Spin"));

        gridLayout->addWidget(Threshold2Spin, 4, 3, 1, 1);

        ApertureSizeSpin = new QSpinBox(canyyeffectcontrol);
        ApertureSizeSpin->setObjectName(QStringLiteral("ApertureSizeSpin"));

        gridLayout->addWidget(ApertureSizeSpin, 5, 3, 1, 1);

        ApertureSizeSlider = new QSlider(canyyeffectcontrol);
        ApertureSizeSlider->setObjectName(QStringLiteral("ApertureSizeSlider"));
        ApertureSizeSlider->setOrientation(Qt::Horizontal);

        gridLayout->addWidget(ApertureSizeSlider, 5, 1, 1, 2);

        Threshold1Slider = new QSlider(canyyeffectcontrol);
        Threshold1Slider->setObjectName(QStringLiteral("Threshold1Slider"));
        Threshold1Slider->setOrientation(Qt::Horizontal);

        gridLayout->addWidget(Threshold1Slider, 2, 1, 1, 1);

        EL2GLabel = new QCheckBox(canyyeffectcontrol);
        EL2GLabel->setObjectName(QStringLiteral("EL2GLabel"));

        gridLayout->addWidget(EL2GLabel, 0, 0, 1, 1);


        retranslateUi(canyyeffectcontrol);

        QMetaObject::connectSlotsByName(canyyeffectcontrol);
    } // setupUi

    void retranslateUi(QWidget *canyyeffectcontrol)
    {
        canyyeffectcontrol->setWindowTitle(QApplication::translate("canyyeffectcontrol", "Canny effect control", 0));
        Threshold1Label->setText(QApplication::translate("canyyeffectcontrol", "Threshold size 1", 0));
        ApertureSizeLabel->setText(QApplication::translate("canyyeffectcontrol", "Aperture size", 0));
        Threshold2Label->setText(QApplication::translate("canyyeffectcontrol", "Threshold size 2", 0));
        EL2GLabel->setText(QApplication::translate("canyyeffectcontrol", "Enable L2G", 0));
    } // retranslateUi

};

namespace Ui {
    class canyyeffectcontrol: public Ui_canyyeffectcontrol {};
} // namespace Ui

QT_END_NAMESPACE

#endif // UI_CANYYEFFECTCONTROL_H

这意味着我应该重写代码以释放内存（例如unique _ ptr），代码应该是这样的

/********************************************************************************
** Form generated from reading UI file 'canyyeffectcontrol.ui'
**
** Created by: Qt User Interface Compiler version 5.0.2
**
** WARNING! All changes made in this file will be lost when recompiling UI file!
** I modify the code 
********************************************************************************/

#ifndef UI_CANYYEFFECTCONTROL_H
#define UI_CANYYEFFECTCONTROL_H

#include <QtCore/QVariant>
#include <QtWidgets/QAction>
#include <QtWidgets/QApplication>
#include <QtWidgets/QButtonGroup>
#include <QtWidgets/QCheckBox>
#include <QtWidgets/QGridLayout>
#include <QtWidgets/QHeaderView>
#include <QtWidgets/QLabel>
#include <QtWidgets/QSlider>
#include <QtWidgets/QSpinBox>
#include <QtWidgets/QWidget>

QT_BEGIN_NAMESPACE

class Ui_canyyeffectcontrol
{
public:
    std::unique_ptr<QGridLayout> gridLayout;
    std::unique_ptr<QSlider> Threshold2Slider;
    std::unique_ptr<QLabel> Threshold1Label;
    std::unique_ptr<QLabel> ApertureSizeLabel;
    std::unique_ptr<QLabel> Threshold2Label;
    std::unique_ptr<QSpinBox>Threshold1Spin;
    std::unique_ptr<QSpinBox> Threshold2Spin;
    std::unique_ptr<QSpinBox> ApertureSizeSpin;
    std::unique_ptr<QSlider> ApertureSizeSlider;
    std::unique_ptr<QSlider> Threshold1Slider;
    std::unique_ptr<QCheckBox> EL2GLabel;

    void setupUi(QWidget *canyyeffectcontrol)
    {
        if (canyyeffectcontrol->objectName().isEmpty())
            canyyeffectcontrol->setObjectName(QStringLiteral("canyyeffectcontrol"));
        canyyeffectcontrol->resize(432, 210);
        canyyeffectcontrol->setMinimumSize(QSize(153, 119));
        canyyeffectcontrol->setMaximumSize(QSize(432, 210));
        gridLayout = std::unique_ptr<QGridLayout> (new QGridLayout(canyyeffectcontrol));
        gridLayout->setObjectName(QStringLiteral("gridLayout"));
        Threshold2Slider =  std::unique_ptr<QSlider>(new QSlider(canyyeffectcontrol));
        Threshold2Slider.get()->setObjectName(QStringLiteral("Threshold2Slider"));
        Threshold2Slider.get()->setOrientation(Qt::Horizontal);

        gridLayout.get()->addWidget(Threshold2Slider.get(), 4, 1, 1, 2);

        Threshold1Label = std::unique_ptr<QLabel> (new QLabel(canyyeffectcontrol));
        Threshold1Label.get()->setObjectName(QStringLiteral("Threshold1Label"));

        gridLayout.get()->addWidget(Threshold1Label.get(), 2, 0, 1, 1);

        ApertureSizeLabel = std::unique_ptr<QLabel> (new QLabel(canyyeffectcontrol));
        ApertureSizeLabel.get()->setObjectName(QStringLiteral("ApertureSizeLabel"));

        gridLayout.get()->addWidget(ApertureSizeLabel.get(), 5, 0, 1, 1);

        Threshold2Label =  std::unique_ptr<QLabel> (new QLabel(canyyeffectcontrol));
        Threshold2Label.get()->setObjectName(QStringLiteral("Threshold2Label"));

        gridLayout.get()->addWidget(Threshold2Label.get(), 4, 0, 1, 1);

        Threshold1Spin =  std::unique_ptr<QSpinBox> (new QSpinBox(canyyeffectcontrol));
        Threshold1Spin.get()->setObjectName(QStringLiteral("Threshold1Spin"));

        gridLayout.get()->addWidget(Threshold1Spin.get(), 2, 3, 1, 1);

        Threshold2Spin =  std::unique_ptr<QSpinBox> (new QSpinBox(canyyeffectcontrol));
        Threshold2Spin.get()->setObjectName(QStringLiteral("Threshold2Spin"));

        gridLayout->addWidget(Threshold2Spin.get(), 4, 3, 1, 1);

        ApertureSizeSpin =  std::unique_ptr<QSpinBox> (new QSpinBox(canyyeffectcontrol));
        ApertureSizeSpin.get()->setObjectName(QStringLiteral("ApertureSizeSpin"));

        gridLayout.get()->addWidget(ApertureSizeSpin.get(), 5, 3, 1, 1);

        ApertureSizeSlider =std::unique_ptr<QSlider> (new QSlider(canyyeffectcontrol));
        ApertureSizeSlider.get()->setObjectName(QStringLiteral("ApertureSizeSlider"));
        ApertureSizeSlider.get()->setOrientation(Qt::Horizontal);

        gridLayout->addWidget(ApertureSizeSlider.get(), 5, 1, 1, 2);

        Threshold1Slider =std::unique_ptr<QSlider> (new QSlider(canyyeffectcontrol));
        Threshold1Slider.get()->setObjectName(QStringLiteral("Threshold1Slider"));
        Threshold1Slider.get()->setOrientation(Qt::Horizontal);

        gridLayout.get()->addWidget(Threshold1Slider.get(), 2, 1, 1, 1);

        EL2GLabel = std::unique_ptr<QCheckBox> (new QCheckBox(canyyeffectcontrol));
        EL2GLabel.get()->setObjectName(QStringLiteral("EL2GLabel"));

        gridLayout.get()->addWidget(EL2GLabel.get(), 0, 0, 1, 1);


        retranslateUi(canyyeffectcontrol);

        QMetaObject::connectSlotsByName(canyyeffectcontrol);
    } // setupUi

    void retranslateUi(QWidget *canyyeffectcontrol)
    {
        canyyeffectcontrol->setWindowTitle(QApplication::translate("canyyeffectcontrol", "Canny effect control", 0));
        Threshold1Label.get()->setText(QApplication::translate("canyyeffectcontrol", "Threshold size 1", 0));
        ApertureSizeLabel.get()->setText(QApplication::translate("canyyeffectcontrol", "Aperture size", 0));
        Threshold2Label.get()->setText(QApplication::translate("canyyeffectcontrol", "Threshold size 2", 0));
        EL2GLabel.get()->setText(QApplication::translate("canyyeffectcontrol", "Enable L2G", 0));
    } // retranslateUi

};

namespace Ui {
    class canyyeffectcontrol: public Ui_canyyeffectcontrol {};
} // namespace Ui

QT_END_NAMESPACE

#endif // UI_CANYYEFFECTCONTROL_H

Answer 1

阅读QObject派生类如何管理内存 - 简而言之，如果QObject是由父项构造的，那么当父项被销毁时它将被销毁。在您的示例中，看起来所有内容都是作为canyyeffectcontrol的子项创建的，因此这些对象将被销毁。

Answer 2

不，不！你不应该修改Qt生成的文件。

第一个原因（在生成的文件的标题中）：

警告！重新编译UI文件时，此文件中所做的所有更改都将丢失！

这意味着每次修改UI中最微小的部分时都会丢失修改（这本身就是一个可怕的问题，每次更改UI都需要一次又一次地修改它）

其次，Qt以自己的方式处理内存，使用父/子小部件机制来处理内存。您可以找到关于此here和here。

的信息

对于生成的文件，您不必关心它。然后，对于您自己的文件（例如自定义小部件），您不应该使用delete，而是照看QObject::deleteLater()

Answer 3

Qt框架构建了一个父子关系树。例如QSlider的构造函数参数是父级。在父母被摧毁后，所有的孩子也会被递归销毁，所以如果你的父母与孩子之间的关系正确，你就没有必要清理任何东西。

如果还有内存丢失（请查看valgrind），这可能是Qt错误，或者您没有正确设置关系。

Qt UI Generator不会释放资源

3 个答案: