Qt中对于窗口边框的设置一般用到setWindowFlags函数。
void setWindowFlags(Qt::WindowFlags type)如果只setWindowFlags(Qt::FramelessWindowHint);
去掉边框，此时会发现，当程序打开后，单击任务栏的按钮，会发现无法最小化，隐藏窗口。
解决的方法是：
setWindowFlags(Qt::Window|Qt::FramelessWindowHint |Qt::WindowSystemMenuHint|Qt::WindowMinimizeButtonHint|Qt::WindowMaximizeButtonHint);
再次测试，发现边框去掉了，而且鼠标点击任务栏图标，也可以显示和隐藏窗口了。
附：
| Qt::Widget |
This is the default type for QWidget. Widgets of this type are child widgets if they have a parent,and independent(独立的) windows if they have no parent. See also Qt::Window and Qt::SubWindow. |
| Qt::Window |
Indicates（标志，象征） that the widget is a window. Usually with a window system frame and a title bar,irrespective of (不管)whether the widget has a parent or not. Note that it is not possible to unset this flag if the widget does not have a parent. |
| Qt::Dialog | Indicates that the widget is a window that should be decorated as a dialog (i.e., typically no maximize or minimize buttons in the title bar). This is the default type for QDialog. If you want to use it as a modal dialog, it should be launched from another window, or have a parent and used with the QWidget::windowModality property. If you make it modal, the dialog will prevent other top-level windows in the application from getting any input. We refer to a top-level window that has a parent as a secondary window. |
| Qt::FramelessWindowHint |
Produces a borderless window. The user cannot move or resize a borderless window via the window system. On X11, the result of the flag is dependent on the window manager and its ability to understand Motif and/or NETWM hints. Most existing modern window managers can handle this. |
| Qt::CustomizeWindowHint | Turns off the default window title hints. |
| Qt::WindowTitleHint | Gives the window a title bar. |
| Qt::WindowSystemMenuHint |
Adds a window system menu, and possibly a close button (for example on Mac). If you need to hide or show a close button, it is more portable to use WindowCloseButtonHint. |
| Qt::WindowMinimizeButtonHint |
Adds a minimize button. On some platforms this implies Qt::WindowSystemMenuHint for it to work. |
| Qt::WindowMaximizeButtonHint |
Adds a maximize button. On some platforms this implies Qt::WindowSystemMenuHint for it to work. |
| Qt::WindowMinMaxButtonsHint |
Adds a minimize and a maximize button. On some platforms this implies Qt::WindowSystemMenuHint for it to work. |
| Qt::WindowCloseButtonHint |
Adds a close button. On some platforms this implies Qt::WindowSystemMenuHint for it to work. |
原文地址：https://www.cnblogs.com/granx/p/9563315.html