使用QGridLayout

Question

我想让ui->centralWidget具有QGridLayout，可滚动。这样做最简单，最舒适的方法是什么？

我尝试过一个简约的项目，但它无法正常工作。 QScrollArea出现在第二个窗口中，测试标签未显示在任何显示的窗口中。我究竟做错了什么？

mainWindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    gridLayout = new QGridLayout();
    ui->centralWidget->setLayout(gridLayout);

    scrollArea = new QScrollArea();
    scrollArea->setBackgroundRole(QPalette::Dark);
    scrollArea->setWidget(ui->centralWidget);

    test = new QLabel("Test");
    gridLayout->addWidget(test,0,0);
    scrollArea->show();
}

MainWindow::~MainWindow()
{
    delete ui;
}

mainWindow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QGridLayout>
#include <QScrollArea>
#include <QLabel>

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();

private:
    Ui::MainWindow *ui;
    QGridLayout *gridLayout;
    QScrollArea *scrollArea;
    QLabel *test;
};

#endif // MAINWINDOW_H

暗示@thuga之后的变化：

不显示标签。

mainWindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    QWidget *testWidget = new QWidget(ui->centralWidget);
    gridLayout = new QGridLayout(testWidget);
    testWidget->setLayout(gridLayout);

    scrollArea = new QScrollArea;
    //scrollArea->setBackgroundRole(QPalette::Dark);
    scrollArea->setWidget(testWidget);
    scrollArea->setFrameShape(QFrame::NoFrame);

    QHBoxLayout *mainLayout = new QHBoxLayout(ui->centralWidget);
    ui->centralWidget->setLayout(mainLayout);
    mainLayout->addWidget(scrollArea);

    test = new QLabel("TESTTESTTESTTESTTEST");
    testWidget->layout()->addWidget(test);
}

MainWindow::~MainWindow()
{
    delete ui;
}

Answer 1

@thuga帮助找到了解决方案，谢谢。我想分享一下。也许对某人有帮助。

以下是简约应用程序的代码：

<强> mainWindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    mainWidget = new QWidget(ui->centralWidget);
    gridLayout = new QGridLayout(mainWidget);
    mainWidget->setLayout(gridLayout);

    scrollArea = new QScrollArea;
    scrollArea->setWidget(mainWidget);
    scrollArea->setWidgetResizable(true);

    mainLayout = new QHBoxLayout(ui->centralWidget);
    ui->centralWidget->setLayout(mainLayout);
    mainLayout->addWidget(scrollArea);

    testLabel = new QLabel("TESTTESTTESTTEST");
    gridLayout->addWidget(testLabel,0,0);
}

MainWindow::~MainWindow()
{
    delete ui;
}

<强> mainWindow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QGridLayout>
#include <QScrollArea>
#include <QLabel>

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();

private:
    Ui::MainWindow *ui;
    QWidget *mainWidget;
    QHBoxLayout *mainLayout;
    QGridLayout *gridLayout;
    QScrollArea *scrollArea;
    QLabel *testLabel;
};

#endif // MAINWINDOW_H