qt的无边框窗口支持拖拽、Aero Snap、窗口阴影等特性
更新（2025-11-26）
更新代码使用QWidget时，简化了代码，相比于原文，删减掉了事件过滤器。
同时标题栏不再需要单独实现，直接绘制在QWidget中即可。
QMainWindow理论也可以，笔者未测试。
以下为普通QWidget的修改内容。
补充知识 Windows Hit-Test 常量（WM_NCHITTEST）
这些宏用于 Windows 消息 WM_NCHITTEST，表示鼠标在窗口上的不同区域。系统和程序可根据这些值处理拖动、调整大小、按钮点击等行为。
| 宏 | 值 | 含义 |
|---|---|---|
HTERROR |
-2 | 错误或无效区域 |
HTTRANSPARENT |
-1 | 鼠标事件穿透，底层窗口处理 |
HTNOWHERE |
0 | 鼠标不在窗口可用区域（窗口外或空白） |
HTCLIENT |
1 | 客户区（窗口内容区） |
HTCAPTION |
2 | 标题栏（可拖动窗口） |
HTSYSMENU |
3 | 系统菜单按钮（左上角小图标，可右键调菜单） |
HTGROWBOX |
4 | 窗口右下角/边缘可拖动调整大小的区域（Resize Box） |
HTSIZE |
4 | 同 HTGROWBOX，兼容历史代码 |
HTSIZEFIRST |
10 | 左边界开始的调整大小序号 |
HTSIZELAST |
17 | 右下角结束的调整大小序号 |
HTMENU |
5 | 菜单栏 |
HTHSCROLL |
6 | 水平滚动条 |
HTVSCROLL |
7 | 垂直滚动条 |
HTMINBUTTON |
8 | 最小化按钮 |
HTMAXBUTTON |
9 | 最大化按钮 |
HTREDUCE |
8 | 同 HTMINBUTTON（兼容） |
HTZOOM |
9 | 同 HTMAXBUTTON（兼容） |
HTLEFT |
10 | 左边框 |
HTRIGHT |
11 | 右边框 |
HTTOP |
12 | 上边框 |
HTTOPLEFT |
13 | 左上角 |
HTTOPRIGHT |
14 | 右上角 |
HTBOTTOM |
15 | 下边框 |
HTBOTTOMLEFT |
16 | 左下角 |
HTBOTTOMRIGHT |
17 | 右下角 |
HTBORDER |
18 | 普通边框（历史保留） |
HTOBJECT |
19 | 客户区内的 OLE 对象或控件（少用） |
HTCLOSE |
20 | 关闭按钮 |
HTHELP |
21 | 帮助按钮 |
修改头文件
- 删除
mousePressEvent、mouseReleaseEvent、mouseMoveEvent的拖动内容 - 重载
bool nativeEvent(const QByteArray& eventType, void* message, long* result) override;函数
qt6 为 nativeEventFilter(const QByteArray &eventType, void *message, qintptr *result)
- 增加
void initWindow()和const int BORDER_WIDTH = 8;
代码总结：
class MyWidget: public QWidget
{
Q_OBJECT
protected:
bool nativeEvent(const QByteArray& eventType, void* message, long* result) override;
private:
void initWindow();
const int BORDER_WIDTH = 8; // 用于调整大小的边缘宽度（像素）
};
修改源文件
- 构造函数调用
initWindow() hitTestWindows函数用来判断当前鼠标位置下，需要做什么操作。以下是函数内容分析，也是读者可能会需要修改的内容：GetWindowRect获取窗口在显示屏的区域，传参x，y是鼠标在显示屏的位置，计算得到localX\localY是鼠标相对于窗口左上角的位置- 获取你自己定义的
TitleBar的geometry()区域范围，也就是TitleBar相对于窗口的位置 - 判断
TitleBar左上角的相对窗口位置pos1是否在（0，0）是为了判断当前是否是全屏状态 - WINDOWS窗口在全屏状态下，四周会有8个像素的拓展宽度，非全屏下，
pos1是（0，0）；全屏下，一般是（8，8） - 因为全屏下，不需要进行顶部边缘的拖动拉伸窗口，所以就不需要把
TitleBar的左上右三个边缘区域排除掉；
否则非全屏下，进行缩减rect范围，便于标题栏四周进行窗口的整体大小拖动修改 - 满足
titleRect.contains(localX, localY)时，意味着鼠标在TitleBar区域内 - 需要排除的区域，返回
HTCLIENT客户区, 其他返回HTCAPTION标题区（这里笔者排除了按钮部分） - 剩余部分是判断窗口边缘的拖动行为
实现部分：
#ifdef _WIN32
#define WIN32_LEAN_AND_MEAN
#include <dwmapi.h>
#include <windows.h>
#include <uxtheme.h>
#pragma comment(lib, "Dwmapi.lib")
#endif
void MyWidget::initWindow()
{
setWindowFlags(Qt::Window | Qt::FramelessWindowHint);
#ifdef _WIN32
HWND hwnd = reinterpret_cast<HWND>(this->winId());
const LONG style = (WS_POPUP | WS_CAPTION | WS_SYSMENU | WS_MINIMIZEBOX | WS_MAXIMIZEBOX | WS_THICKFRAME | WS_CLIPCHILDREN);
SetWindowLongPtr(hwnd, GWL_STYLE, style);
const MARGINS shadow = { 1, 1, 1, 1 };
DwmExtendFrameIntoClientArea(hwnd, &shadow);
SetWindowPos(hwnd, 0, 0, 0, 0, 0, SWP_FRAMECHANGED | SWP_NOMOVE | SWP_NOSIZE);
#endif
}
#ifdef _WIN32
static LRESULT hitTestWindows(QWidget* widget, HWND hwnd, int x, int y, int borderWidth)
{
// x,y are screen coords
RECT winRect;
if (!GetWindowRect(hwnd, &winRect)) return HTNOWHERE;
int localX = x - winRect.left;
int localY = y - winRect.top;
QWidget* window = widget;
QWidget* title = window->findChild<QWidget*>("wgt_TitleBar");
if (title) {
QRect titleRect = title->geometry();
if (titleRect.left() == 0 && titleRect.top() == 0) {
titleRect.adjust(borderWidth, borderWidth, -borderWidth, 0);
}
if (titleRect.contains(localX, localY)) {
QList<QAbstractButton*> btns = title->findChildren<QAbstractButton*>();
for (QAbstractButton* b : btns)
{
if (b->geometry().contains(localX, localY)) {
return HTCLIENT;
}
}
QLabel* icon = window->findChild<QLabel*>("icon_label");
if (icon && icon->geometry().contains(localX, localY)){
return HTSYSMENU;
}
return HTCAPTION; // 只有标题栏区域返回标题栏
}
}
int left = winRect.left;
int top = winRect.top;
int right = winRect.right;
int bottom = winRect.bottom;
// Determine if point is in border areas
bool topArea = y >= top && y < top + borderWidth;
bool bottomArea = y < bottom && y >= bottom - borderWidth;
bool leftArea = x >= left && x < left + borderWidth;
bool rightArea = x < right && x >= right - borderWidth;
// Corners
if (topArea && leftArea) return HTTOPLEFT;
if (topArea && rightArea) return HTTOPRIGHT;
if (bottomArea && leftArea) return HTBOTTOMLEFT;
if (bottomArea && rightArea) return HTBOTTOMRIGHT;
// Edges
if (leftArea) return HTLEFT;
if (rightArea) return HTRIGHT;
if (topArea) return HTTOP;
if (bottomArea) return HTBOTTOM;
return HTCLIENT;
}
#endif
bool MyWidget::nativeEvent(const QByteArray& eventType, void* message, long* result)
{
#ifdef _WIN32
#define GET_X_LPARAM(lp) ((int)(short)LOWORD(lp))
#define GET_Y_LPARAM(lp) ((int)(short)HIWORD(lp))
// Windows-specific native event handling
if (eventType == "windows_generic_MSG" || eventType == "windows_dispatcher_MSG") {
MSG* msg = static_cast<MSG*>(message);
switch (msg->message) {
case WM_NCCALCSIZE:
{
// this kills the window frame and title bar we added with WS_THICKFRAME and WS_CAPTION
*result = 0;
return true;
}
case WM_NCHITTEST: {
// convert to screen coords
POINT pt;
pt.x = GET_X_LPARAM(msg->lParam);
pt.y = GET_Y_LPARAM(msg->lParam);
HWND hwnd = (HWND)winId();
// get hit test result based on border width
LRESULT h = hitTestWindows(this, hwnd, pt.x, pt.y, BORDER_WIDTH);
*result = h;
return true; // handled
}
// 若full时边框不合适，可以去除此case
case WM_GETMINMAXINFO:
{
if (::IsZoomed(msg->hwnd)) {
// 最大化时会超出屏幕，所以填充边框间距
RECT frame = { 0, 0, 0, 0 };
AdjustWindowRectEx(&frame, WS_OVERLAPPEDWINDOW, FALSE, 0);
frame.left = abs(frame.left);
frame.top = abs(frame.bottom);
this->setContentsMargins(frame.left, frame.top, frame.right, frame.bottom);
}
else {
this->setContentsMargins(0, 0, 0, 0);
}
*result = ::DefWindowProc(msg->hwnd, msg->message, msg->wParam, msg->lParam);
return true;
}
default:
break;
}
}
#endif
return QWidget::nativeEvent(eventType, message, result);
}
原文
环境：Desktop Qt 6.7.2 MSVC2019 64bit
需要的库：dwmapi.lib、user32.lib
需要头文件：<dwmapi.h>、<windowsx.h>
只显示重要代码
1、去除原边框、加上阴影、Aero Snap以及其他动画特效
（1）头文件
#include "Windows.h"
#include "uxtheme.h"
#include "dwmapi.h"
#include "titlebar.h"//自定义类
（2）去除标题、原边框
初始化，去除边框
void MainWindow::init()
{
setWindowFlags(Qt::Window | Qt::FramelessWindowHint);
#ifdef Q_OS_WIN
HWND hwnd = reinterpret_cast<HWND>(this->winId());
const LONG style = ( WS_POPUP | WS_CAPTION | WS_SYSMENU | WS_MINIMIZEBOX | WS_MAXIMIZEBOX | WS_THICKFRAME | WS_CLIPCHILDREN );
SetWindowLongPtr(hwnd, GWL_STYLE, style);
const MARGINS shadow = {1, 1, 1, 1};
DwmExtendFrameIntoClientArea(hwnd, &shadow);
SetWindowPos(hwnd, 0, 0, 0, 0, 0, SWP_FRAMECHANGED | SWP_NOMOVE | SWP_NOSIZE);
#endif
// 标题拖动、双击事件
MyTitleBar *title = new MyTitleBar(this);
qobject_cast<QBoxLayout *>(ui->centralwidget->layout())->insertWidget(0, title);
}
同时在最大化时，增加了边界，可以自行删除
若使用qt5，重载 bool nativeEvent(const QByteArray &eventType, void *message, long *result);
bool MainWindow::nativeEvent(const QByteArray& eventType, void* message, qintptr* result)
{
MSG* msg = (MSG*)message;
switch (msg->message)
{
case WM_NCCALCSIZE:
{
// this kills the window frame and title bar we added with WS_THICKFRAME and WS_CAPTION
*result = 0;
return true;
}
// 若full时边框不合适，可以去除此case
case WM_GETMINMAXINFO:
{
if (::IsZoomed(msg->hwnd)) {
// 最大化时会超出屏幕，所以填充边框间距
RECT frame = { 0, 0, 0, 0 };
AdjustWindowRectEx(&frame, WS_OVERLAPPEDWINDOW, FALSE, 0);
frame.left = abs(frame.left);
frame.top = abs(frame.bottom);
this->setContentsMargins(frame.left, frame.top, frame.right, frame.bottom);
}
else {
this->setContentsMargins(0, 0, 0, 0);
}
*result = ::DefWindowProc(msg->hwnd, msg->message, msg->wParam, msg->lParam);
return true;
}
break;
default:
return QMainWindow::nativeEvent(eventType, message, result);
}
}
（3）支持手动修改窗口
需要实现一个QAbstractNativeEventFilter 类，内容如下：
头文件
#include <QAbstractNativeEventFilter>
#include <QWidget>
#include "Windows.h"
#define GET_X_LPARAM(lp) ((int)(short)LOWORD(lp))
#define GET_Y_LPARAM(lp) ((int)(short)HIWORD(lp))
class NativeEventFilter : public QAbstractNativeEventFilter
{
public:
virtual bool nativeEventFilter(const QByteArray &eventType, void *message, qintptr *result)Q_DECL_OVERRIDE;
};
cpp文件
bool NativeEventFilter::nativeEventFilter(const QByteArray &eventType, void *message, qintptr *result)
{
#ifdef Q_OS_WIN
if (eventType != "windows_generic_MSG")
return false;
MSG* msg = static_cast<MSG*>(message);
QWidget* widget = QWidget::find(reinterpret_cast<WId>(msg->hwnd));
if (!widget)
return false;
switch (msg->message) {
case WM_NCHITTEST: {
const LONG borderWidth = 9;
RECT winrect;
GetWindowRect(msg->hwnd, &winrect);
long x = GET_X_LPARAM(msg->lParam);
long y = GET_Y_LPARAM(msg->lParam);
// bottom left
if (x >= winrect.left && x < winrect.left + borderWidth &&
y < winrect.bottom && y >= winrect.bottom - borderWidth)
{
*result = HTBOTTOMLEFT;
return true;
}
// bottom right
if (x < winrect.right && x >= winrect.right - borderWidth &&
y < winrect.bottom && y >= winrect.bottom - borderWidth)
{
*result = HTBOTTOMRIGHT;
return true;
}
// top left
if (x >= winrect.left && x < winrect.left + borderWidth &&
y >= winrect.top && y < winrect.top + borderWidth)
{
*result = HTTOPLEFT;
return true;
}
// top right
if (x < winrect.right && x >= winrect.right - borderWidth &&
y >= winrect.top && y < winrect.top + borderWidth)
{
*result = HTTOPRIGHT;
return true;
}
// left
if (x >= winrect.left && x < winrect.left + borderWidth)
{
*result = HTLEFT;
return true;
}
// right
if (x < winrect.right && x >= winrect.right - borderWidth)
{
*result = HTRIGHT;
return true;
}
// bottom
if (y < winrect.bottom && y >= winrect.bottom - borderWidth)
{
*result = HTBOTTOM;
return true;
}
// top
if (y >= winrect.top && y < winrect.top + borderWidth)
{
*result = HTTOP;
return true;
}
return false;
}
default:
break;
}
return false;
#else
return false;
#endif
};
应用
然后在窗口创建之前，使用QApplication::installNativeEventFilter 方法把监听器注册给主程序。
int main(int argc, char *argv[])
{
NativeEventFilter f;
QApplication a(argc, argv);
a.installNativeEventFilter(&f);//支持手动修改窗口大小
MainWindow w;
w.show();
return a.exec();
}
2、自定义标题栏
- 需要重载
QWidget::mousePressEvent方法 - 保存 Window 句柄操作原窗口
class MyTitleBar : public QFrame {
Q_OBJECT
public:
explicit MyTitleBar(QWidget *parent = nullptr);
protected:
void mousePressEvent(QMouseEvent* ev);
private:
QWidget *Window = nullptr; // 保存主窗口的指针
QVBoxLayout *verticalLayout;
QHBoxLayout *horizontalLayout;
QSpacerItem *horizontalSpacer;
QPushButton *pushButton_min;
QPushButton *pushButton_normal;
QPushButton *pushButton_max;
QPushButton *pushButton_full;
QSpacerItem *horizontalSpacer_6;
QPushButton *pushButton_close;
};
创建ui
MyTitleBar::MyTitleBar(QWidget *parent): QFrame (parent), Window(parent)
{
// 边缘贴合
parent->setContentsMargins(0, 0, 0, 0);
setObjectName("title");
setMaximumHeight(50);
this->setStyleSheet("#title{background-color: rgb(255, 255, 255);}");
verticalLayout = new QVBoxLayout(this);
verticalLayout->setObjectName("verticalLayout");
verticalLayout->setContentsMargins(0, 0, 0, 0);
horizontalLayout = new QHBoxLayout();
horizontalLayout->setObjectName("horizontalLayout");
horizontalSpacer = new QSpacerItem(40, 20, QSizePolicy::Policy::Expanding, QSizePolicy::Policy::Minimum);
horizontalLayout->addItem(horizontalSpacer);
pushButton_min = new QPushButton(this);
pushButton_min->setObjectName("pushButton_min");
horizontalLayout->addWidget(pushButton_min);
pushButton_normal = new QPushButton(this);
pushButton_normal->setObjectName("pushButton_normal");
horizontalLayout->addWidget(pushButton_normal);
pushButton_max = new QPushButton(this);
pushButton_max->setObjectName("pushButton_max");
horizontalLayout->addWidget(pushButton_max);
pushButton_full = new QPushButton(this);
pushButton_full->setObjectName("pushButton_full");
horizontalLayout->addWidget(pushButton_full);
horizontalSpacer_6 = new QSpacerItem(40, 20, QSizePolicy::Policy::Expanding, QSizePolicy::Policy::Minimum);
horizontalLayout->addItem(horizontalSpacer_6);
pushButton_close = new QPushButton(this);
pushButton_close->setObjectName("pushButton_close");
horizontalLayout->addWidget(pushButton_close);
horizontalLayout->setStretch(0, 1);
verticalLayout->addLayout(horizontalLayout);
pushButton_min->setText(QCoreApplication::translate("MainWindow", "MIN", nullptr));
pushButton_normal->setText(QCoreApplication::translate("MainWindow", "NORMAL", nullptr));
pushButton_max->setText(QCoreApplication::translate("MainWindow", "MAX", nullptr));
pushButton_full->setText(QCoreApplication::translate("MainWindow", "FULL", nullptr));
pushButton_close->setText(QCoreApplication::translate("MainWindow", "CLOSE", nullptr));
}
连接主窗口的变化
最大化和关闭按扭，正常调用QWidget::showMaximized()和QWidget::close() 等Qt自带方法即可。
connect(pushButton_min, &QPushButton::clicked, Window, &QWidget::showMinimized);
connect(pushButton_close, &QPushButton::clicked, Window, &QWidget::close);
connect(pushButton_normal, &QPushButton::clicked, Window, &QWidget::showNormal);
connect(pushButton_full, &QPushButton::clicked, Window, &QWidget::showFullScreen);
connect(pushButton_max, &QPushButton::clicked, Window, &QWidget::showMaximized);
重截QWidget::mousePressEvent 方法
#include "Windows.h"
void MyTitleBar::mousePressEvent(QMouseEvent* ev)
{
QWidget::mousePressEvent(ev);
if (Window == nullptr) return;
if (!ev->isAccepted()) {
if (ev->type() == QEvent::MouseButtonDblClick) {
// Toggle maximize/restore on double-click
if (Window->isMaximized()) {
Window->showNormal(); // Restore
}
else {
Window->showMaximized(); // Maximize
}
return; // Prevent further processing
}
#ifdef Q_OS_WIN
ReleaseCapture();
SendMessage(reinterpret_cast<HWND>(Window->winId()), WM_SYSCOMMAND, SC_MOVE + HTCAPTION, 0);
#endif
}
}
添加
// 标题拖动、双击事件
MyTitleBar *title = new MyTitleBar(this);
qobject_cast<QBoxLayout *>(ui->centralwidget->layout())->insertWidget(0, title);
3、最终实现效果
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