QAbstractNativeEventFilter 類

The QAbstractNativeEventFilter class provides an interface for receiving native events, such as MSG or XCB event structs. 更多...

頭：	#include <QAbstractNativeEventFilter>
qmake:	QT += core
Since:	Qt 5.0

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公共函數

	QAbstractNativeEventFilter ()
virtual	~QAbstractNativeEventFilter ()
virtual bool	nativeEventFilter (const QByteArray & eventType , void * message , long * result ) = 0

詳細描述

The QAbstractNativeEventFilter class provides an interface for receiving native events, such as MSG or XCB event structs.

成員函數文檔編製

QAbstractNativeEventFilter:: QAbstractNativeEventFilter ()

創建本機事件過濾器。

By default this doesn't do anything. Remember to install it on the application object.

`[虛擬]` QAbstractNativeEventFilter:: ~QAbstractNativeEventFilter ()

銷毀本機事件過濾器。

這會從應用程序中自動移除它。

`[pure virtual]` bool QAbstractNativeEventFilter:: nativeEventFilter (const QByteArray & eventType , void * message , long * result )

此方法被調用，為每個本機事件。

注意： 此處的過濾器函數接收本機消息，例如：MSG 或 XCB 事件結構。

It is called by the QPA platform plugin. On Windows, it is called by the event dispatcher.

The type of event eventType is specific to the platform plugin chosen at run-time, and can be used to cast message to the right type.

在 X11， eventType is set to "xcb_generic_event_t", and the message can be casted to a xcb_generic_event_t pointer.

在 Windows， eventType is set to "windows_generic_MSG" for messages sent to toplevel windows, and "windows_dispatcher_MSG" for system-wide messages such as messages from a registered hot key. In both cases, the message can be casted to a MSG pointer. The result pointer is only used on Windows, and corresponds to the LRESULT pointer.

On macOS , eventType is set to "mac_generic_NSEvent", and the message can be casted to an NSEvent pointer.

在此函數的重實現中，若希望過濾 message 即：停止進一步處理，返迴 true；否則返迴 false。

Linux 範例

class MyXcbEventFilter : public QAbstractNativeEventFilter
{
public:
    bool nativeEventFilter(const QByteArray &eventType, void *message, long *) override
    {
        if (eventType == "xcb_generic_event_t") {
            xcb_generic_event_t* ev = static_cast<xcb_generic_event_t *>(message);
            // ...
        }
        return false;
    }
};

macOS 範例

mycocoaeventfilter.h:

#include <QAbstractNativeEventFilter>
class MyCocoaEventFilter : public QAbstractNativeEventFilter
{
public:
    bool nativeEventFilter(const QByteArray &eventType, void *message, long *) override;
};

mycocoaeventfilter.mm:

#include "mycocoaeventfilter.h"
#import <AppKit/AppKit.h>
bool CocoaNativeEventFilter::nativeEventFilter(const QByteArray &eventType, void *message, long *)
{
    if (eventType == "mac_generic_NSEvent") {
        NSEvent *event = static_cast<NSEvent *>(message);
        if ([event type] == NSKeyDown) {
            // Handle key event
            qDebug() << QString::fromNSString([event characters]);
        }
    }
    return false;
}

myapp.pro:

HEADERS += mycocoaeventfilter.h
OBJECTIVE_SOURCES += mycocoaeventfilter.mm
LIBS += -framework AppKit

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