- Qt 5.15
- Qt GUI
- C++ Classes
- Key
- Qt 5.15.19 Reference Documentation

# Key Class

class QPixmapCache::Key

The QPixmapCache::Key class can be used for efficient access to the QPixmapCache. More...

This class was introduced in Qt 4.6.

- List of all members, including inherited members

## Public Functions

| Key()
| ~Key()
bool | isValid() const

## Detailed Description

Use 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.

## Member Function Documentation

### Key::Key()

Constructs an empty Key object.

### Key::~Key()

Destroys the key.

### bool Key::isValid() const

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 Otherwise, if pixmap was flushed, the key is no longer valid.

This function was introduced in Qt 5.7.