用Qt制作无边框窗口

Question

我是 Qt C++ 新手。我下载了最新的 Windows 版本，做了一些教程，非常棒。

我看到了 Qt 框架具有的一些样式选项，而且它很棒，但现在我需要构建我的应用程序，其主窗口（形式）是用没有矩形边框（无边框？）的图像设计/蒙皮的。

我怎样才能用Qt做到这一点？

Answer 1

如果您正在寻找小部件形状的一些高级样式，也许这个示例会对您有所帮助：

形状时钟示例

或者您可能只是在寻找这种标志：Qt::CustomizeWindowHint 或只是 Qt::FramelessWindowHint 。

Answer 2

我创建了一个小例子，说明如何在 Qt5 中创建类似 VS2013 的无框窗口：

您可以在这里获取完整的源代码：https ://github.com/Jorgen-VikingGod/Qt-Frameless-Window-DarkStyle

另外，这里是如何将“主”主窗口嵌入到“无框架”窗口中的代码概述。您还可以了解如何添加标题栏、按钮以及如何最大化、调整大小和移动无框窗口。

mainwindow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QtWidgets>

/*
place your QMainWindow code here
*/
namespace Ui {
  class MainWindow;
}

class MainWindow : public QMainWindow
{
  Q_OBJECT
public:
  explicit MainWindow(QWidget *parent = 0);
  ~MainWindow();
private:
  Ui::MainWindow *ui;
};

/*
this class is to add frameless window supoort and do all the stuff with titlebar and buttons
*/
class BorderlessMainWindow: public QMainWindow
{
  Q_OBJECT
public:
  explicit BorderlessMainWindow(QWidget *parent = 0);
  ~BorderlessMainWindow() {}
protected:
  void mouseMoveEvent(QMouseEvent* event);
  void mousePressEvent(QMouseEvent* event);
  void mouseReleaseEvent(QMouseEvent* event);
  void mouseDoubleClickEvent(QMouseEvent *event);
private slots:
  void slot_minimized();
  void slot_restored();
  void slot_maximized();
  void slot_closed();
private:
  MainWindow *mMainWindow;
  QWidget *mTitlebarWidget;
  QLabel *mWindowTitle;
  QPushButton *mMinimizeButton;
  QPushButton *mRestoreButton;
  QPushButton *mMaximizeButton;
  QPushButton *mCloseButton;
  QPoint mLastMousePosition;
  bool mMoving;
  bool mMaximized;
};

#endif // MAINWINDOW_H

mainwindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QDebug>

/*
frameless window class: it adds the MainWindow class inside the centralWidget
*/
BorderlessMainWindow::BorderlessMainWindow(QWidget *parent) : QMainWindow(parent, Qt::CustomizeWindowHint ) {
  setObjectName("borderlessMainWindow");
  setWindowFlags(Qt::FramelessWindowHint| Qt::WindowSystemMenuHint);
  // to fix taskbar minimize feature
  setWindowFlags(windowFlags() | Qt::WindowMinimizeButtonHint);

  mMainWindow = new MainWindow(this);
  setWindowTitle(mMainWindow->windowTitle());

  QVBoxLayout *verticalLayout = new QVBoxLayout();
  verticalLayout->setSpacing(0);
  verticalLayout->setMargin(1);

  QHBoxLayout *horizontalLayout = new QHBoxLayout();
  horizontalLayout->setSpacing(0);
  horizontalLayout->setMargin(0);

  mTitlebarWidget = new QWidget(this);
  mTitlebarWidget->setObjectName("titlebarWidget");
  mTitlebarWidget->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Preferred);
  mTitlebarWidget->setLayout(horizontalLayout);

  mMinimizeButton = new QPushButton(mTitlebarWidget);
  mMinimizeButton->setObjectName("minimizeButton");
  connect(mMinimizeButton, SIGNAL(clicked()), this, SLOT(slot_minimized()));

  mRestoreButton = new QPushButton(mTitlebarWidget);
  mRestoreButton->setObjectName("restoreButton");
  mRestoreButton->setVisible(false);
  connect(mRestoreButton, SIGNAL(clicked()), this, SLOT(slot_restored()));

  mMaximizeButton = new QPushButton(mTitlebarWidget);
  mMaximizeButton->setObjectName("maximizeButton");
  connect(mMaximizeButton, SIGNAL(clicked()), this, SLOT(slot_maximized()));

  mCloseButton = new QPushButton(mTitlebarWidget);
  mCloseButton->setObjectName("closeButton");
  connect(mCloseButton, SIGNAL(clicked()), this, SLOT(slot_closed()));

  mWindowTitle = new QLabel(mTitlebarWidget);
  mWindowTitle->setObjectName("windowTitle");
  mWindowTitle->setText(windowTitle());

  horizontalLayout->addWidget(mWindowTitle);
  horizontalLayout->addStretch(1);
  horizontalLayout->addWidget(mMinimizeButton);
  horizontalLayout->addWidget(mRestoreButton);
  horizontalLayout->addWidget(mMaximizeButton);
  horizontalLayout->addWidget(mCloseButton);

  verticalLayout->addWidget(mTitlebarWidget);
  verticalLayout->addWidget(mMainWindow);

  QWidget *centralWidget = new QWidget(this);
  centralWidget->setObjectName("centralWidget");
  centralWidget->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
  centralWidget->setLayout(verticalLayout);

  setCentralWidget(centralWidget);
}
void BorderlessMainWindow::mousePressEvent(QMouseEvent* event) {
  if (!mTitlebarWidget->underMouse() && !mWindowTitle->underMouse())
    return;

  if(event->button() == Qt::LeftButton) {
    mMoving = true;
    mLastMousePosition = event->pos();
  }
}
void BorderlessMainWindow::mouseMoveEvent(QMouseEvent* event) {
  if (!mTitlebarWidget->underMouse() && !mWindowTitle->underMouse())
    return;

  if( event->buttons().testFlag(Qt::LeftButton) && mMoving) {
    this->move(this->pos() + (event->pos() - mLastMousePosition));
  }
}
void BorderlessMainWindow::mouseReleaseEvent(QMouseEvent* event) {
  if (!mTitlebarWidget->underMouse() && !mWindowTitle->underMouse())
    return;

  if(event->button() == Qt::LeftButton) {
    mMoving = false;
  }
}
void BorderlessMainWindow::mouseDoubleClickEvent(QMouseEvent *event) {
  Q_UNUSED(event);
  if (!mTitlebarWidget->underMouse() && !mWindowTitle->underMouse())
    return;

  mMaximized = !mMaximized;
  if (mMaximized) {
    slot_maximized();
  } else {
    slot_restored();
  }
}
void BorderlessMainWindow::slot_minimized() {
  setWindowState(Qt::WindowMinimized);
}
void BorderlessMainWindow::slot_restored() {
  mRestoreButton->setVisible(false);
  mMaximizeButton->setVisible(true);
  setWindowState(Qt::WindowNoState);
  setStyleSheet("#borderlessMainWindow{border:1px solid palette(highlight);}");
}
void BorderlessMainWindow::slot_maximized() {
  mRestoreButton->setVisible(true);
  mMaximizeButton->setVisible(false);
  setWindowState(Qt::WindowMaximized);
  setStyleSheet("#borderlessMainWindow{border:1px solid palette(base);}");
}
void BorderlessMainWindow::slot_closed() {
  close();
}

/*
MainWindow class: put all your code here
*/
MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent, Qt::FramelessWindowHint), ui(new Ui::MainWindow) {
  ui->setupUi(this);
  statusBar()->setSizeGripEnabled(true);
}

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

Answer 3

您的 Qt 目录中有一个示例应用程序： examples/小部件/windowsflags。

Answer 4

我自己也遇到过这个问题，并在一段时间后弄清楚了。查看 https://github.com/ianbannerman/TrueFramelessWindow 以获取适用于 Windows 和 Windows 的示例代码。 macOS。

Qt::FramelessWindowHint 牺牲了调整大小和最小/最大/关闭，因此可能不是大多数人正在寻找的。