QPointingDeviceUniqueId identifies a unique object, such as a tagged token or stylus, which is used with a pointing device. 更多...
| 头： | #include <QPointingDeviceUniqueId> |
| qmake: | QT += gui |
| Since: | Qt 5.8 |
| QPointingDeviceUniqueId () | |
| bool | isValid () const |
| qint64 | numericId () const |
| QPointingDeviceUniqueId | fromNumericId (qint64 id ) |
| uint | qHash (QPointingDeviceUniqueId key , uint seed = 0) |
| bool | operator!= (QPointingDeviceUniqueId lhs , QPointingDeviceUniqueId rhs ) |
| bool | operator== (QPointingDeviceUniqueId lhs , QPointingDeviceUniqueId rhs ) |
QPointingDeviceUniqueId identifies a unique object, such as a tagged token or stylus, which is used with a pointing device.
QPointingDeviceUniqueIds can be compared for equality, and can be used as keys in a QHash . You get access to the numerical ID via numericId (), if the device supports such IDs. For future extensions, though, you should not use that function, but compare objects of this type using the equality operator.
This class is a thin wrapper around an integer ID. You pass it into and out of functions by value.
This type actively prevents you from holding it in a QList , because doing so would be very inefficient. Use a QVector instead, which has the same API as QList , but more efficient storage.
另请参阅 QTouchEvent::TouchPoint .
This property holds the numeric unique ID of the token represented by a touchpoint
If the device provides a numeric ID, isValid () returns true, and this property provides the numeric ID; otherwise it is -1.
You should not use the value of this property in portable code, but instead rely on equality to identify pointers.
访问函数：
| qint64 | numericId () const |
另请参阅 isValid ().
构造无效的唯一指针 ID。
[static]
QPointingDeviceUniqueId
QPointingDeviceUniqueId::
fromNumericId
(
qint64
id
)
Constructs a unique pointer ID from numeric ID id .
Returns whether this unique pointer ID is valid, that is, it represents an actual pointer.
返回哈希值为 key ，使用 seed 做计算种子。
该函数在 Qt 5.8 引入。
Returns whether the two unique pointer IDs
lhs
and
rhs
identify different pointers (
true
) or not (
false
).
该函数在 Qt 5.8 引入。
Returns whether the two unique pointer IDs
lhs
and
rhs
identify the same pointer (
true
) or not (
false
).
该函数在 Qt 5.8 引入。