Key 类

class QPixmapCache ::Key

The QPixmapCache::Key 类可以用于有效访问 QPixmapCache . 更多...

公共函数

Key ()
~Key ()
bool isValid () const
void swap (QPixmapCache::Key & other )
(从 6.6 起) size_t qHash (const QPixmapCache::Key & key , size_t seed = 0)

详细描述

使用 QPixmapCache::insert () to receive an instance of Key generated by the pixmap cache. You can store the key in your own objects for a very efficient one-to-one object-to-pixmap mapping.

成员函数文档编制

Key:: Key ()

构造空的 Key 对象。

[noexcept] Key:: ~Key ()

销毁 Key。

[noexcept] bool Key:: isValid () const

返回 true if there is a cached pixmap associated with this key. Otherwise, if pixmap was flushed, the key is no longer valid.

[noexcept] void Key:: swap ( QPixmapCache::Key & other )

Swaps this key with other 。此操作非常快且从不失败。

相关非成员

[noexcept, since 6.6] size_t qHash (const QPixmapCache::Key & key , size_t seed = 0)

返回哈希值为 key ,使用 seed 做计算种子。

该函数在 Qt 6.6 引入。