ReferenceError: WeakRef is not defined/main.dart.js:32087 at Object._RouteEntry$ (http://192.168.125.92/main.dart.js:30255:124)/main.dart.js:32087 at NavigatorState_restoreState_closure.call$1 (http://192.168.125.92/main.dart.js:102519:16)/main.dart.js:32087 at MappedListIterable.elementAt...
References to the weakref function are converted into references of the target name. If the target name is not defined in the current translation unit and it is not referenced directly or otherwise in a way that requires a definition of the target, for example if it is only referenced by us...
Weak references arehashableif theobjectis hashable. They will maintain their hash value even after theobjectwas deleted. Ifhash()is called the first time only after theobjectwas deleted, the call will raiseTypeError. Weak references support tests for equality, but not ordering. If the referents...
检测一个弱引用对象是否仍然存在应该使用表达式 ref() is not None。 通常,需要使用引用对象的应用代码应当遵循这样的模式: # r is a weak reference object o = r() if o is None: # referent has been garbage collected print("Object has been deallocated; can't frobnicate.") else: print("Object...
{// An Evaluator is declared for the finalizer to// insure that any errors that might occur do not spill into// the call that triggered the collection:Evaluator evalr;try{ wr->finalize(); }catch(CommandTerminated) { }// ExposeWeakRefto reference-counting collection:wr->m_self =0; ...
A weak reference to an object is not enough to keep the object alive: when the only remaining references to areferent(i.e. an object which is referred to by a weak reference) are weak references, garbage collection is free to destroy the referent and reuse its memory for something else....
exc_info=None, extra=None, frame=None, dispatcher=None):#: the name of the logger that created it or any other textual#: channel description. This is a descriptive name and should not#: be used for filtering. A log record might have a#: :attr:`dispatcher` defined which provides more...
ref(o) >>> o2 = r() >>> o is o2 True 如果引用已不存在,则调用引用对象将返回 None: >>> >>> del o, o2 >>> print(r()) None 检测一个弱引用对象是否仍然存在应该使用表达式 ref() is not None。 通常,需要使用引用对象的应用代码应当遵循这样的模式: # r is a weak reference object...
"""idSpanner = id(spanner)ifidSpannernotinself.keys():raiseSpannersException("cannot return comoponents from an object not defined in spanners: %s"% repr(spanner) ) post = []# get all objects, unwrap# second index is list of componentsforwrinself._storage[idSpanner][1]: ...
self.assertNotNone(parent_pool_ref())delpool self.assertNone(pool_ref()) self.assertNone(parent_pool_ref())# Ensure that AssertionErrors are raised when a pool is deleted twicenewpool = Pool() newpool2 = Pool(newpool) svn_pool_clear(newpool) ...