QContextMenuEvent 类包含上下文菜单事件的描述参数。 更多...
| 头： |
#include <QContextMenuEvent>
|
| CMake: |
find_package(Qt6 REQUIRED COMPONENTS Gui)
target_link_libraries(mytarget PRIVATE Qt6::Gui)
|
| qmake: |
QT += gui
|
| 继承： | QInputEvent |
| enum | Reason { Mouse, Keyboard, Other } |
| QContextMenuEvent (QContextMenuEvent::Reason reason , const QPoint & pos , const QPoint & globalPos , Qt::KeyboardModifiers modifiers = Qt::NoModifier) | |
| const QPoint & | globalPos () const |
| int | globalX () const |
| int | globalY () const |
| const QPoint & | pos () const |
| QContextMenuEvent::Reason | reason () const |
| int | x () const |
| int | y () const |
A context menu event is sent when a user performs an action that should open a contextual menu:
The expected context menu should contain actions that are relevant to some content within the application (the "context"). In Qt, the context is at least the particular widget or Qt Quick Item that receives the QContextMenuEvent. If there is a selection, that should probably be treated as the context. The context can be further refined using QContextMenuEvent::pos () to pinpoint the content within the widget, item or selection.
Widgets can override QWidget::contextMenuEvent () to handle this event. Many widgets already do that, and have useful context menus by default. Some widgets have a function such as createStandardContextMenu () to populate the default set of actions into a QMenu , which can be customized further in your subclass and then shown.
In Qt Quick, the event can be handled via the ContextMenu attached property. Some QtQuick.Controls Controls already provide context menus by default.
Unlike most synthetic events (such as a QMouseEvent that is sent only after a QTouchEvent or QTabletEvent was not accepted), QContextMenuEvent is sent regardless of whether the original mouse or key event was already handled and accepted . This is to accommodate the Windows UI pattern of selecting some kind of items (icons, drawing elements, or cells in an Item View) using the right mouse button (clicking or dragging), and then getting a context menu as soon as you release the right mouse button. (The actions on the menu are meant to apply to the selection.) Therefore, on Windows the QContextMenuEvent is sent on mouse release; while on other platforms, it's sent on press. Qt follows the platform convention 在默认情况下。
There are also some Qt Quick Controls such as Pane that accept mouse events, and nevertheless receive a QContextMenuEvent after a mouse press or click.
If you prefer to support the press-drag-release UI pattern to open a context menu on press, and drag over a menu item to select it on release, you will need to do that by handling
QMouseEvents
directly (by overriding
virtual functions
in
QWidget
subclasses, or using
TapHandler
to open a Menu in Qt Quick); and then the QContextMenuEvent will be redundant when the
reason
() 是
Mouse
. You should
ignore
() the event in that case; but you should still ensure that the widget, custom control or application can respond to a QContextMenuEvent that
comes from
the platform-specific keyboard shortcut.
When a QContextMenuEvent is ignored , Qt attempts to deliver it to other widgets and/or Items under the position (which is usually translated from the cursor position).
此枚举描述事件为什么被发送的原因。
| 常量 | 值 | 描述 |
|---|---|---|
QContextMenuEvent::Mouse
|
0
|
鼠标导致事件被发送。通常，这意味着点击鼠标右键，但这从属平台。 |
QContextMenuEvent::Keyboard
|
1
|
键盘导致此事件被发送。在 Windows，这意味着按下菜单按钮。 |
QContextMenuEvent::Other
|
2
|
事件是通过某些其它手段发送的 (即：不通过鼠标或键盘)。 |
构造上下文菜单事件对象，采用将 accept (接受) 参数标志设为 false。
The reason 参数必须是 QContextMenuEvent::Mouse or QContextMenuEvent::Keyboard .
The pos 参数指定相对于接收 Widget 的鼠标位置。 globalPos 是按绝对坐标的鼠标位置。 modifiers 保持键盘修饰符。
返回事件发生时的鼠标指针全局位置。
返回事件发生时的鼠标指针全局 X 位置。
另请参阅 globalY () 和 globalPos ().
返回事件发生时的鼠标指针全局 Y 位置。
另请参阅 globalX () 和 globalPos ().
返回指针相对于接收事件 Widget 的鼠标指针位置。
注意：
若
QContextMenuEvent
did not come from the right mouse button,
pos()
可以是
null
.
另请参阅 x (), y ()，和 globalPos ().
返回此上下文事件的原因。
返回鼠标指针的 X 位置，相对于接收事件 Widget。
返回鼠标指针的 Y 位置，相对于接收事件 Widget。
