以编程方式设计 GUI - 嵌套布局和多个小部件 (Qt) 的良好实践

我有兴趣更好地理解Qt为此我想see 如何仅以编程方式完成嵌套布局和多个小部件 GUI 的相对复杂示例;即不使用 Qt Creator 的设计。

我见过几个示例代码仅演示非常简单的布局，并且几乎总是不使用头文件；事实上我见过的大多数例子，dumpmain 中的代码。据我了解（如果我错了，请纠正我），良好的编程实践要求您将设计分离到单独的类中（例如mainwindow）并且在main.cpp你只需调用和show那个主窗口。也许，最关键的是，所有小部件、布局等的定义都应该在头文件中定义，然后在头文件中调用和定制。mainwindow.cpp.

可以看到以编程方式良好编程实践的一个很好的例子，但对于相对简单的 GUI 设计here https://stackoverflow.com/a/39649750/6167676.

如果有人可以提供在线资源其中良好的编程 GUI 设计的非简单代码示例展示了如何正确定义和自定义嵌套布局和小部件，我们将非常感激。

或者，这里有一个简单的编程 GUI 设计示例，如果能够从中导出代码（无需设计器）以供我学习和理解，那就太好了：

note: 我的重点仅在于嵌套布局、多个小部件以及在不同的 Qt 源文件上定义和调用这些部件的位置和方式.

可以在此处查看嵌套布局和小部件的详细信息：

实际的 GUI 结果如下所示：

UPDATE

正如迈克在评论部分所建议的那样，uic https://doc.qt.io/qt-5/uic.html可以看到设计器所做的代码，在我的例子中，上面提到的示例如下

>uic mainwindow.ui输出：

#ifndef UI_MAINWINDOW_H
#define UI_MAINWINDOW_H

#include <QtCore/QVariant>
#include <QtWidgets/QAction>
#include <QtWidgets/QApplication>
#include <QtWidgets/QButtonGroup>
#include <QtWidgets/QFormLayout>
#include <QtWidgets/QFrame>
#include <QtWidgets/QGridLayout>
#include <QtWidgets/QHBoxLayout>
#include <QtWidgets/QHeaderView>
#include <QtWidgets/QLabel>
#include <QtWidgets/QLineEdit>
#include <QtWidgets/QMainWindow>
#include <QtWidgets/QProgressBar>
#include <QtWidgets/QPushButton>
#include <QtWidgets/QSpacerItem>
#include <QtWidgets/QVBoxLayout>
#include <QtWidgets/QWidget>

QT_BEGIN_NAMESPACE

class Ui_MainWindow
{
public:
    QWidget *centralWidget;
    QVBoxLayout *verticalLayout_3;
    QFrame *top_frame;
    QGridLayout *gridLayout;
    QSpacerItem *horizontalSpacer;
    QProgressBar *progressBar_2;
    QProgressBar *progressBar_4;
    QSpacerItem *verticalSpacer;
    QSpacerItem *horizontalSpacer_2;
    QPushButton *pushButton_1;
    QProgressBar *progressBar_1;
    QPushButton *pushButton_2;
    QPushButton *pushButton_3;
    QProgressBar *progressBar_3;
    QPushButton *pushButton_4;
    QFrame *bottom_frame;
    QHBoxLayout *horizontalLayout;
    QFrame *frame;
    QFormLayout *formLayout;
    QLabel *label_1;
    QLabel *label_2;
    QSpacerItem *verticalSpacer_2;
    QLineEdit *lineEdit;
    QLineEdit *lineEdit_2;
    QFrame *frame_2;
    QHBoxLayout *horizontalLayout_2;
    QLabel *label_3;
    QSpacerItem *horizontalSpacer_3;
    QLabel *label_4;

    void setupUi(QMainWindow *MainWindow)
    {
        if (MainWindow->objectName().isEmpty())
            MainWindow->setObjectName(QStringLiteral("MainWindow"));
        MainWindow->resize(878, 632);
        centralWidget = new QWidget(MainWindow);
        centralWidget->setObjectName(QStringLiteral("centralWidget"));
        verticalLayout_3 = new QVBoxLayout(centralWidget);
        verticalLayout_3->setSpacing(6);
        verticalLayout_3->setContentsMargins(11, 11, 11, 11);
        verticalLayout_3->setObjectName(QStringLiteral("verticalLayout_3"));
        top_frame = new QFrame(centralWidget);
        top_frame->setObjectName(QStringLiteral("top_frame"));
        QSizePolicy sizePolicy(QSizePolicy::Preferred, QSizePolicy::Expanding);
        sizePolicy.setHorizontalStretch(0);
        sizePolicy.setVerticalStretch(0);
        sizePolicy.setHeightForWidth(top_frame->sizePolicy().hasHeightForWidth());
        top_frame->setSizePolicy(sizePolicy);
        top_frame->setFrameShape(QFrame::StyledPanel);
        top_frame->setFrameShadow(QFrame::Raised);
        gridLayout = new QGridLayout(top_frame);
        gridLayout->setSpacing(6);
        gridLayout->setContentsMargins(11, 11, 11, 11);
        gridLayout->setObjectName(QStringLiteral("gridLayout"));
        horizontalSpacer = new QSpacerItem(30, 20, QSizePolicy::Fixed, QSizePolicy::Minimum);

        gridLayout->addItem(horizontalSpacer, 0, 2, 1, 1);

        progressBar_2 = new QProgressBar(top_frame);
        progressBar_2->setObjectName(QStringLiteral("progressBar_2"));
        progressBar_2->setValue(24);

        gridLayout->addWidget(progressBar_2, 2, 3, 1, 1);

        progressBar_4 = new QProgressBar(top_frame);
        progressBar_4->setObjectName(QStringLiteral("progressBar_4"));
        progressBar_4->setValue(24);

        gridLayout->addWidget(progressBar_4, 2, 5, 1, 1);

        verticalSpacer = new QSpacerItem(20, 10, QSizePolicy::Minimum, QSizePolicy::Fixed);

        gridLayout->addItem(verticalSpacer, 1, 1, 1, 1);

        horizontalSpacer_2 = new QSpacerItem(10, 20, QSizePolicy::Fixed, QSizePolicy::Minimum);

        gridLayout->addItem(horizontalSpacer_2, 0, 4, 1, 1);

        pushButton_1 = new QPushButton(top_frame);
        pushButton_1->setObjectName(QStringLiteral("pushButton_1"));

        gridLayout->addWidget(pushButton_1, 0, 0, 1, 1);

        progressBar_1 = new QProgressBar(top_frame);
        progressBar_1->setObjectName(QStringLiteral("progressBar_1"));
        progressBar_1->setValue(24);

        gridLayout->addWidget(progressBar_1, 0, 3, 1, 1);

        pushButton_2 = new QPushButton(top_frame);
        pushButton_2->setObjectName(QStringLiteral("pushButton_2"));

        gridLayout->addWidget(pushButton_2, 0, 1, 1, 1);

        pushButton_3 = new QPushButton(top_frame);
        pushButton_3->setObjectName(QStringLiteral("pushButton_3"));

        gridLayout->addWidget(pushButton_3, 2, 0, 1, 1);

        progressBar_3 = new QProgressBar(top_frame);
        progressBar_3->setObjectName(QStringLiteral("progressBar_3"));
        progressBar_3->setValue(24);

        gridLayout->addWidget(progressBar_3, 0, 5, 1, 1);

        pushButton_4 = new QPushButton(top_frame);
        pushButton_4->setObjectName(QStringLiteral("pushButton_4"));

        gridLayout->addWidget(pushButton_4, 2, 1, 1, 1);


        verticalLayout_3->addWidget(top_frame);

        bottom_frame = new QFrame(centralWidget);
        bottom_frame->setObjectName(QStringLiteral("bottom_frame"));
        bottom_frame->setFrameShape(QFrame::StyledPanel);
        bottom_frame->setFrameShadow(QFrame::Raised);
        horizontalLayout = new QHBoxLayout(bottom_frame);
        horizontalLayout->setSpacing(6);
        horizontalLayout->setContentsMargins(11, 11, 11, 11);
        horizontalLayout->setObjectName(QStringLiteral("horizontalLayout"));
        frame = new QFrame(bottom_frame);
        frame->setObjectName(QStringLiteral("frame"));
        frame->setFrameShape(QFrame::StyledPanel);
        frame->setFrameShadow(QFrame::Raised);
        formLayout = new QFormLayout(frame);
        formLayout->setSpacing(6);
        formLayout->setContentsMargins(11, 11, 11, 11);
        formLayout->setObjectName(QStringLiteral("formLayout"));
        label_1 = new QLabel(frame);
        label_1->setObjectName(QStringLiteral("label_1"));

        formLayout->setWidget(0, QFormLayout::LabelRole, label_1);

        label_2 = new QLabel(frame);
        label_2->setObjectName(QStringLiteral("label_2"));

        formLayout->setWidget(1, QFormLayout::LabelRole, label_2);

        verticalSpacer_2 = new QSpacerItem(20, 20, QSizePolicy::Minimum, QSizePolicy::Expanding);

        formLayout->setItem(2, QFormLayout::LabelRole, verticalSpacer_2);

        lineEdit = new QLineEdit(frame);
        lineEdit->setObjectName(QStringLiteral("lineEdit"));
        QSizePolicy sizePolicy1(QSizePolicy::Expanding, QSizePolicy::Expanding);
        sizePolicy1.setHorizontalStretch(0);
        sizePolicy1.setVerticalStretch(0);
        sizePolicy1.setHeightForWidth(lineEdit->sizePolicy().hasHeightForWidth());
        lineEdit->setSizePolicy(sizePolicy1);

        formLayout->setWidget(3, QFormLayout::SpanningRole, lineEdit);

        lineEdit_2 = new QLineEdit(frame);
        lineEdit_2->setObjectName(QStringLiteral("lineEdit_2"));
        sizePolicy1.setHeightForWidth(lineEdit_2->sizePolicy().hasHeightForWidth());
        lineEdit_2->setSizePolicy(sizePolicy1);

        formLayout->setWidget(4, QFormLayout::LabelRole, lineEdit_2);


        horizontalLayout->addWidget(frame);

        frame_2 = new QFrame(bottom_frame);
        frame_2->setObjectName(QStringLiteral("frame_2"));
        frame_2->setFrameShape(QFrame::StyledPanel);
        frame_2->setFrameShadow(QFrame::Raised);
        horizontalLayout_2 = new QHBoxLayout(frame_2);
        horizontalLayout_2->setSpacing(6);
        horizontalLayout_2->setContentsMargins(11, 11, 11, 11);
        horizontalLayout_2->setObjectName(QStringLiteral("horizontalLayout_2"));
        label_3 = new QLabel(frame_2);
        label_3->setObjectName(QStringLiteral("label_3"));

        horizontalLayout_2->addWidget(label_3);

        horizontalSpacer_3 = new QSpacerItem(40, 20, QSizePolicy::Fixed, QSizePolicy::Minimum);

        horizontalLayout_2->addItem(horizontalSpacer_3);

        label_4 = new QLabel(frame_2);
        label_4->setObjectName(QStringLiteral("label_4"));

        horizontalLayout_2->addWidget(label_4);

        frame->raise();
        frame->raise();
        label_3->raise();
        label_4->raise();

        horizontalLayout->addWidget(frame_2);


        verticalLayout_3->addWidget(bottom_frame);

        MainWindow->setCentralWidget(centralWidget);

        retranslateUi(MainWindow);

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

    void retranslateUi(QMainWindow *MainWindow)
    {
        MainWindow->setWindowTitle(QApplication::translate("MainWindow", "MainWindow", 0));
        pushButton_1->setText(QApplication::translate("MainWindow", "PushButton_1", 0));
        pushButton_2->setText(QApplication::translate("MainWindow", "PushButton_2", 0));
        pushButton_3->setText(QApplication::translate("MainWindow", "PushButton_3", 0));
        pushButton_4->setText(QApplication::translate("MainWindow", "PushButton_4", 0));
        label_1->setText(QApplication::translate("MainWindow", "TextLabel_1", 0));
        label_2->setText(QApplication::translate("MainWindow", "TextLabel_2", 0));
        label_3->setText(QApplication::translate("MainWindow", "TextLabel_3", 0));
        label_4->setText(QApplication::translate("MainWindow", "TextLabel_4", 0));
    } // retranslateUi

};

namespace Ui {
    class MainWindow: public Ui_MainWindow {};
} // namespace Ui

QT_END_NAMESPACE

#endif // UI_MAINWINDOW_H

以下是您可能希望执行的转换。我已经包含了您的代码的缩短版本来进行演示。

1. 从...开始uic output.

   class Ui_MainWindow
   {
   public:
       QWidget *centralWidget;
       QVBoxLayout *verticalLayout_3;
       QFrame *top_frame;
   };
   

2. 将所有成员Ui_Foo into Foo本身，保留它们的顺序。

   class MainWindow : public QMainWindow
   {
       QWidget *centralWidget;
       QVBoxLayout *verticalLayout_3;
       QFrame *top_frame;
   };
   

3. 将成员类型从指针更改为值。

   class MainWindow : public QMainWindow
   {
       QWidget centralWidget;
       QVBoxLayout verticalLayout_3;
       QFrame top_frame;
       ...
   };
   

4. 通过为它们提供它们所作用的小部件来初始化类声明中的布局。这使得用户界面的结构从标题本身就变得显而易见：

   class MainWindow : public QMainWindow
   {
       QWidget centralWidget;
       QVBoxLayout verticalLayout_3{&centralWidget};
       QFrame top_frame;
       ...
   };
   

5. 添加代码来自setupUi到构造函数的主体，适当地更改它以作用于值，而不是指针：

   MainWindow::MainWindow(QWidget * parent) : QWidget{parent}
   {
       setObjectName(QStringLiteral("MainWindow"));
       resize(878, 632);
       centralWidget.setObjectName(QStringLiteral("centralWidget"));
       verticalLayout_3.setSpacing(6);
       verticalLayout_3.setContentsMargins(11, 11, 11, 11);
       verticalLayout_3.setObjectName(QStringLiteral("verticalLayout_3"));
       top_frame.setObjectName(QStringLiteral("top_frame"));
       QSizePolicy sizePolicy(QSizePolicy::Preferred, QSizePolicy::Expanding);
       sizePolicy.setHorizontalStretch(0);
       sizePolicy.setVerticalStretch(0);
       sizePolicy.setHeightForWidth(top_frame->sizePolicy().hasHeightForWidth());
       top_frame.setSizePolicy(sizePolicy);
       top_frame.setFrameShape(QFrame::StyledPanel);
       top_frame.setFrameShadow(QFrame::Raised);
       ...
   }