基于QMainWindow 实现的效果很好的 Qt 无边框窗口
Qt实现自定义窗口
基于 QMainWindow 实现的效果很好的 Qt 无边框窗口,支持 Windows 和 OS X 系统。在 Windows 上，支持窗口阴影、Aero 效果等；在 OS X 上，支持原生窗口样式，比如窗口圆角、窗口阴影、三个系统按钮(关闭、最小化、最大化）等。
window效果
OSX
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#ifndef CFRAMELESSWINDOW_H
#define CFRAMELESSWINDOW_H
#include "qsystemdetection.h"
#include #include "framelesswindow.h"
#include (message);
const auto msg = static_cast<LPMSG>(message);
#endif
if (!msg->hwnd) {
// Why sometimes the window handle is null? Is it designed to be?
// Anyway, we should skip it in this case.
return false;
}
switch (msg->message)
{
case WM_NCCALCSIZE:
{
// Windows是根据这个消息的返回值来设置窗口的客户区（窗口中真正显示的内容）
// 和非客户区（标题栏、窗口边框、菜单栏和状态栏等Windows系统自行提供的部分
// ，不过对于Qt来说，除了标题栏和窗口边框，非客户区基本也都是自绘的）的范
// 围的，lParam里存放的就是新客户区的几何区域，默认是整个窗口的大小，正常
// 的程序需要修改这个参数，告知系统窗口的客户区和非客户区的范围（一般来说可
// 以完全交给Windows，让其自行处理，使用默认的客户区和非客户区），因此如果
// 我们不修改lParam，就可以使客户区充满整个窗口，从而去掉标题栏和窗口边框
// （因为这些东西都被客户区给盖住了。但边框阴影也会因此而丢失，不过我们会使
// 用其他方式将其带回，请参考其他消息的处理，此处不过多提及）。但有个情况要
// 特别注意，那就是窗口最大化后，窗口的实际尺寸会比屏幕的尺寸大一点，从而使
// 用户看不到窗口的边界，这样用户就不能在窗口最大化后调整窗口的大小了（虽然
// 这个做法听起来特别奇怪，但Windows确实就是这样做的），因此如果我们要自行
// 处理窗口的非客户区，就要在窗口最大化后，将窗口边框的宽度和高度（一般是相
// 等的）从客户区裁剪掉，否则我们窗口所显示的内容就会超出屏幕边界，显示不全。
// 如果用户开启了任务栏自动隐藏，在窗口最大化后，还要考虑任务栏的位置。因为
// 如果窗口最大化后，其尺寸和屏幕尺寸相等（因为任务栏隐藏了，所以窗口最大化
// 后其实是充满了整个屏幕，变相的全屏了），Windows会认为窗口已经进入全屏的
// 状态，从而导致自动隐藏的任务栏无法弹出。要避免这个状况，就要使窗口的尺寸
// 小于屏幕尺寸。我下面的做法参考了火狐、Chromium和Windows Terminal
// 如果没有开启任务栏自动隐藏，是不存在这个问题的，所以要先进行判断。
// 一般情况下，*result设置为0（相当于DefWindowProc的返回值为0）就可以了，
// 根据MSDN的说法，返回0意为此消息已经被程序自行处理了，让Windows跳过此消
// 息，否则Windows会添加对此消息的默认处理，对于当前这个消息而言，就意味着
// 标题栏和窗口边框又会回来，这当然不是我们想要的结果。根据MSDN，当wParam
// 为FALSE时，只能返回0，但当其为TRUE时，可以返回0，也可以返回一个WVR_常
// 量。根据Chromium的注释，当存在非客户区时，如果返回WVR_REDRAW会导致子
// 窗口/子控件出现奇怪的bug（自绘控件错位），并且Lucas在Windows 10
// 上成功复现，说明这个bug至今都没有解决。我查阅了大量资料，发现唯一的解决
// 方案就是返回0。但如果不存在非客户区，且wParam为TRUE，最好返回
// WVR_REDRAW，否则窗口在调整大小可能会产生严重的闪烁现象。
// 虽然对大多数消息来说，返回0都代表让Windows忽略此消息，但实际上不同消息
// 能接受的返回值是不一样的，请注意自行查阅MSDN。
// Sent when the size and position of a window's client area must be
// calculated. By processing this message, an application can
// control the content of the window's client area when the size or
// position of the window changes. If wParam is TRUE, lParam points
// to an NCCALCSIZE_PARAMS structure that contains information an
// application can use to calculate the new size and position of the
// client rectangle. If wParam is FALSE, lParam points to a RECT
// structure. On entry, the structure contains the proposed window
// rectangle for the window. On exit, the structure should contain
// the screen coordinates of the corresponding window client area.
// The client area is the window's content area, the non-client area
// is the area which is provided by the system, such as the title
// bar, the four window borders, the frame shadow, the menu bar, the
// status bar, the scroll bar, etc. But for Qt, it draws most of the
// window area (client + non-client) itself. We now know that the
// title bar and the window frame is in the non-client area and we
// can set the scope of the client area in this message, so we can
// remove the title bar and the window frame by let the non-client
// area be covered by the client area (because we can't really get
// rid of the non-client area, it will always be there, all we can
// do is to hide it) , which means we should let the client area's
// size the same with the whole window's size. So there is no room
// for the non-client area and then the user won't be able to see it
// again. But how to achieve this? Very easy, just leave lParam (the
// re-calculated client area) untouched. But of course you can
// modify lParam, then the non-client area will be seen and the
// window borders and the window frame will show up. However, things
// are quite different when you try to modify the top margin of the
// client area. DWM will always draw the whole title bar no matter
// what margin value you set for the top, unless you don't modify it
// and remove the whole top area (the title bar + the one pixel
// height window border). This can be confirmed in Windows
// Terminal's source code, you can also try yourself to verify
// it. So things will become quite complicated if you want to
// preserve the four window borders. So we just remove the whole
// window frame, otherwise the code will become much more complex.
if (msg->wParam == FALSE) {
*result = 0;
return true;
}
if(::IsZoomed(msg->hwnd)) {
*result = WVR_REDRAW;
return true;
} else {
*result = 0;
return true;
}
// NCCALCSIZE_PARAMS& params = *reinterpret_cast(msg->lParam);
//if (params.rgrc[0].top != 0)
// params.rgrc[0].top -= 1;
// //this kills the window frame and title bar we added with WS_THICKFRAME and WS_CAPTION
// *result = WVR_REDRAW;
// return true;
}
case WM_NCHITTEST:
{
// 原生Win32窗口只有顶边是在窗口内部resize的，其余三边都是在窗口
// 外部进行resize的，其原理是，WS_THICKFRAME这个窗口样式会在窗
// 口的左、右和底边添加三个透明的resize区域，这三个区域在正常状态
// 下是完全不可见的，它们由DWM负责绘制和控制。这些区域的宽度等于
// (SM_CXSIZEFRAME + SM_CXPADDEDBORDER)，高度等于
// (SM_CYSIZEFRAME + SM_CXPADDEDBORDER)，在100%缩放时，均等
// 于8像素。它们属于窗口区域的一部分，但不属于客户区，而是属于非客
// 户区，因此GetWindowRect获取的区域中是包含这三个resize区域的，
// 而GetClientRect获取的区域是不包含它们的。当把
// DWMWA_EXTENDED_FRAME_BOUNDS作为参数调用
// DwmGetWindowAttribute时，也能获取到一个窗口大小，这个大小介
// 于前面两者之间，暂时不知道这个数据的意义及其作用。我们在
// WM_NCCALCSIZE消息的处理中，已经把整个窗口都设置为客户区了，也
// 就是说，我们的窗口已经没有非客户区了，因此那三个透明的resize区
// 域，此刻也已经成为窗口客户区的一部分了，从而变得不透明了。所以
// 现在的resize，看起来像是在窗口内部resize，是因为原本透明的地方
// 现在变得不透明了，实际上，单纯从范围上来看，现在我们resize的地方，
// 就是普通窗口的边框外部，那三个透明区域的范围。
// 因此，如果我们把边框完全去掉（就是我们正在做的事情），resize就
// 会看起来是在内部进行，这个问题通过常规方法非常难以解决。我测试过
// QQ和钉钉的窗口，它们的窗口就是在外部resize，但实际上它们是通过
// 把窗口实际的内容，嵌入到一个完全透明的但尺寸要大一圈的窗口中实现
// 的，虽然看起来效果还行，但在我看来不是正途。而且我之所以能发现，
// 也是由于这种方法在很多情况下会露馅，比如窗口未响应卡住或贴边的时
// 候，能明显看到窗口周围多出来一圈边界。我曾经尝试再把那三个区域弄
// 透明，但无一例外都会破坏DWM绘制的边框阴影，因此只好作罢。
// As you may have found, if you use this code, the resize areas
// will be inside the frameless window, however, a normal Win32
// window can be resized outside of it. Here is the reason: the
// WS_THICKFRAME window style will cause a window has three
// transparent areas beside the window's left, right and bottom
// edge. Their width or height is eight pixels if the window is not
// scaled. In most cases, they are totally invisible. It's DWM's
// responsibility to draw and control them. They exist to let the
// user resize the window, visually outside of it. They are in the
// window area, but not the client area, so they are in the
// non-client area actually. But we have turned the whole window
// area into client area in WM_NCCALCSIZE, so the three transparent
// resize areas also become a part of the client area and thus they
// become visible. When we resize the window, it looks like we are
// resizing inside of it, however, that's because the transparent
// resize areas are visible now, we ARE resizing outside of the
// window actually. But I don't know how to make them become
// transparent again without breaking the frame shadow drawn by DWM.
// If you really want to solve it, you can try to embed your window
// into a larger transparent window and draw the frame shadow
// yourself. As what we have said in WM_NCCALCSIZE, you can only
// remove the top area of the window, this will let us be able to
// resize outside of the window and don't need much process in this
// message, it looks like a perfect plan, however, the top border is
// missing due to the whole top area is removed, and it's very hard
// to bring it back because we have to use a trick in WM_PAINT
// (learned from Windows Terminal), but no matter what we do in
// WM_PAINT, it will always break the backing store mechanism of Qt,
// so actually we can't do it. And it's very difficult to do such
// things in NativeEventFilters as well. What's worse, if we really
// do this, the four window borders will become white and they look
// horrible in dark mode. This solution only supports Windows 10
// because the border width on Win10 is only one pixel, however it's
// eight pixels on Windows 7 so preserving the three window borders
// looks terrible on old systems. I'm testing this solution in
// another branch, if you are interested in it, you can give it a
// try.
*result = 0;
const LONG border_width = m_borderWidth;
RECT winrect;
GetWindowRect(HWND(winId()), &winrect);
long x = GET_X_LPARAM(msg->lParam);
long y = GET_Y_LPARAM(msg->lParam);
if(m_bResizeable)
{
bool resizeWidth = minimumWidth() != maximumWidth();
bool resizeHeight = minimumHeight() != maximumHeight();
if(resizeWidth)
{
//left border
if (x >= winrect.left && x < winrect.left + border_width)
{
*result = HTLEFT;
}
//right border
if (x < winrect.right && x >= winrect.right - border_width)
{
*result = HTRIGHT;
}
}
if(resizeHeight)
{
//bottom border
if (y < winrect.bottom && y >= winrect.bottom - border_width)
{
*result = HTBOTTOM;
}
//top border
if (y >= winrect.top && y < winrect.top + border_width)
{
*result = HTTOP;
}
}
if(resizeWidth && resizeHeight)
{
//bottom left corner
if (x >= winrect.left && x < winrect.left + border_width &&
y < winrect.bottom && y >= winrect.bottom - border_width)
{
*result = HTBOTTOMLEFT;
}
//bottom right corner
if (x < winrect.right && x >= winrect.right - border_width &&
y < winrect.bottom && y >= winrect.bottom - border_width)
{
*result = HTBOTTOMRIGHT;
}
//top left corner
if (x >= winrect.left && x < winrect.left + border_width &&
y >= winrect.top && y < winrect.top + border_width)
{
*result = HTTOPLEFT;
}
//top right corner
if (x < winrect.right && x >= winrect.right - border_width &&
y >= winrect.top && y < winrect.top + border_width)
{
*result = HTTOPRIGHT;
}
}
}
if (0!=*result) return true;
//*result仍然等于0，说明鼠标位置不在上述的边框范围内，则还有可能处于标题栏范围内
//标题栏效果(win7 及以上)：
//1. 双击标题栏，窗口在最大化、正常化之间切换
//2. 拖动标题栏时，可以移动窗口，移动时如果鼠标触碰到桌面顶端，则最大化窗口等类似效果
//*result still equals 0, that means the cursor locate OUTSIDE the frame area
//but it may locate in titlebar area
if (!m_titlebar) return false;
//support highdpi
double dpr = this->devicePixelRatioF();
QPoint pos = m_titlebar->mapFromGlobal(QPoint(x/dpr,y/dpr));
if (!m_titlebar->rect().contains(pos)) return false;
QWidget* child = m_titlebar->childAt(pos);
if (!child)
{
*result = HTCAPTION;
return true;
}else{
if (m_whiteList.contains(child))
{
*result = HTCAPTION;
return true;
}
}
return false;
} //end case WM_NCHITTEST
case WM_GETMINMAXINFO:
{
if (::IsZoomed(msg->hwnd)) {
RECT frame = { 0, 0, 0, 0 };
AdjustWindowRectEx(&frame, WS_OVERLAPPEDWINDOW, FALSE, 0);
//record frame area data
double dpr = this->devicePixelRatioF();
m_frames.setLeft(abs(frame.left)/dpr+0.5);
m_frames.setTop(abs(frame.bottom)/dpr+0.5);
m_frames.setRight(abs(frame.right)/dpr+0.5);
m_frames.setBottom(abs(frame.bottom)/dpr+0.5);
QMainWindow::setContentsMargins(m_frames.left()+m_margins.left(), \
m_frames.top()+m_margins.top(), \
m_frames.right()+m_margins.right(), \
m_frames.bottom()+m_margins.bottom());
m_bJustMaximized = true;
}else {
if (m_bJustMaximized)
{
QMainWindow::setContentsMargins(m_margins);
m_frames = QMargins();
m_bJustMaximized = false;
}
}
return false;
}
default:
return QMainWindow::nativeEvent(eventType, message, result);
}
}
void CFramelessWindow::setContentsMargins(const QMargins &margins)
{
QMainWindow::setContentsMargins(margins+m_frames);
m_margins = margins;
}
void CFramelessWindow::setContentsMargins(int left, int top, int right, int bottom)
{
QMainWindow::setContentsMargins(left+m_frames.left(),\
top+m_frames.top(), \
right+m_frames.right(), \
bottom+m_frames.bottom());
m_margins.setLeft(left);
m_margins.setTop(top);
m_margins.setRight(right);
m_margins.setBottom(bottom);
}
QMargins CFramelessWindow::contentsMargins() const
{
QMargins margins = QMainWindow::contentsMargins();
margins -= m_frames;
return margins;
}
void CFramelessWindow::getContentsMargins(int *left, int *top, int *right, int *bottom) const
{
QMainWindow::getContentsMargins(left,top,right,bottom);
if (!(left&&top&&right&&bottom)) return;
if (isMaximized())
{
*left -= m_frames.left();
*top -= m_frames.top();
*right -= m_frames.right();
*bottom -= m_frames.bottom();
}
}
QRect CFramelessWindow::contentsRect() const
{
QRect rect = QMainWindow::contentsRect();
int width = rect.width();
int height = rect.height();
rect.setLeft(rect.left() - m_frames.left());
rect.setTop(rect.top() - m_frames.top());
rect.setWidth(width);
rect.setHeight(height);
return rect;
}
void CFramelessWindow::showFullScreen()
{
if (isMaximized())
{
QMainWindow::setContentsMargins(m_margins);
m_frames = QMargins();
}
QMainWindow::showFullScreen();
}
#endif //Q_OS_WIN
使用方法，就是QWidget 继承 CFramelessWindow类
class MainWindow : public CFramelessWindow
{
}
完整代码：
demo下载地址：
https://download.csdn.net/download/ZLOZL/21569440?spm=1001.2014.3001.5503
QtCustomWindow/src at master · liamlife/QtCustomWindow (github.com)