是否可以将qt枚举值转换为其键?
例如,我想知道QPrinter.A4 = 0
从QPrinter类获得'A4'提前谢谢
答案 0 :(得分:3)
通常,您可以使用QMetaObject
:
m = QtGui.QFrame.staticMetaObject
m.enumerator(m.indexOfEnumerator('Shadow')).valueToKey(QtGui.QFrame.Sunken)
'Sunken'
然而,似乎QPrinter
没有公开元对象,所以你必须通过在Python中遍历QPrinter
的属性来做到这一点(幸运的是,PyQt枚举是{{1的子类},所以可以通过int
)识别:
isinstance
答案 1 :(得分:2)
使用vars
和isinstance
构建枚举的双向映射:
>>> from PyQt4.QtGui import QPrinter
>>> pagesizes = {}
>>> for key, value in vars(QPrinter).iteritems():
... if isinstance(value, QPrinter.PageSize):
... pagesizes[key] = value
... pagesizes[value] = key
...
>>> pagesizes['A4']
0
>>> pagesizes[QPrinter.A4]
'A4'
>>> pagesizes[0]
'A4'
<强>更新强>
似乎vars()
不适用于所有版本的PyQt,但dir()
可能会这样做。因此,更强大的解决方案可能是:
>>> pagesizes = {}
>>> for key in dir(QPrinter):
... value = getattr(QPrinter, key)
... if isinstance(value, QPrinter.PageSize):
... pagesizes[key] = value
... pagesizes[value] = key
...
(注意:仅用 pyqt-4.10.3 / qt-4.8.5 , pyqt-4.10 / qt-5.1.1 和 pyqt-进行测试5.1 / QT-5.1.1 )
答案 2 :(得分:1)
我根据ecatmur的回答实现了一个功能:
def qenum_key(base, value):
"""Convert a Qt Enum value to its key as a string.
Args:
base: The object the enum is in, e.g. QFrame.
value: The value to get.
Return:
The key associated with the value as a string, or None.
"""
klass = value.__class__
try:
idx = klass.staticMetaObject.indexOfEnumerator(klass.__name__)
except AttributeError:
idx = -1
if idx != -1:
return klass.staticMetaObject.enumerator(idx).valueToKey(value)
else:
for name, obj in vars(base).items():
if isinstance(obj, klass) and obj == value:
return name
return None
这首先尝试通过QMetaObject获取值,如果失败或者没有元对象,则返回纯Python方法。
答案 3 :(得分:0)
此实现类似于 The Compiler's one,但找出基类 (QPrinter, QFrame 等)本身。
import sys
def enum_key(enum_val, with_val=False):
"""
Return name of Qt enum value.
`enum_val` - enum value
`with_val` (bool) - return value as part of name
"""
enum_cls = enum_val.__class__
parent = sys.modules.get(enum_cls.__module__)
for i in enum_cls.__qualname__.split(".")[:-1]:
parent = getattr(parent, i)
m = getattr(parent, "staticMetaObject", None)
if m:
idx = m.indexOfEnumerator(enum_cls.__name__)
name = m.enumerator(idx).valueToKey(enum_val)
else:
for n, val in vars(parent).items():
if isinstance(val, enum_cls) and val == enum_val:
name = n
break
return "%s (%d)" % (name, enum_val) if with_val else name
# from PyQt5 import QtPrintSupport
# print(enum_key(QtPrintSupport.QPrinter.A5, with_val=1))
# >> A5 (9)