def QObject对象名称和属性(self):
obj0 = QObject()
obj1 = QObject()
obj2 = QObject()
obj3 = QObject()
obj4 = QObject()
obj5 = QObject()
obj2.setObjectName("2")
obj3.setObjectName("3")
print("obj0", obj0)
print("obj1", obj1)
print("obj2", obj2)
print("obj3", obj3)
print("obj4", obj4)
print("obj5", obj5)
obj1.setParent(obj0)
obj2.setParent(obj0)
obj3.setParent(obj1)
obj4.setParent(obj2)
obj5.setParent(obj2)
print(obj1.parent())
print(obj2.parent())
print(obj0.children())
print(obj0.findChildren(QObject, None, Qt.FindChildrenRecursively))
print(obj0.findChild(QObject, "2", Qt.FindChildrenRecursively))
#********************内存管理***************************开始
obj1 = QObject()
self.obj1 = obj1
obj2 = QObject()
obj2.setParent(obj1)
# 监听obj2对象被释放
obj2.destroyed.connect(lambda _: print("obj2对象被释放了"))
del self.obj1
class CommandStack(collections.abc.Collection):
def __init__(self):
self._parent = QObject(None)
self._index = 0
self._command_number = 1
def __len__(self):
return len(self._parent.children())
def __iter__(self):
self._index = 0
return self
def __next__(self):
if len(self) == 0:
raise StopIteration
if self._index < len(self):
self._index += 1
return self._parent.children()[self._index - 1]
raise StopIteration
def __contains__(self, item):
if isinstance(item, str):
# testing by string name and not reference
item_name = item
find_me = self._parent.findChild(item_name)
if find_me is not None:
return True
return False
# testing by references
for itm in self:
if item is itm:
return True
return False
def __eq__(self, other):
equals = [
len(self) == len(other),
]
equals = equals + list(
map(lambda x, y: x is y, iter(self), iter(other)))
return all(equals)
def __del__(self):
self._parent.deleteLater()
def push(self, command):
if not isinstance(command, QObject):
raise TypeError
if command.parent() is not None:
raise AttributeError('Command QObject already has a parent!')
command.setParent(self._parent)
command.setObjectName('Command_{}'.format(self._command_number))
self._command_number += 1
def pop(self):
last_index = len(self) - 1
last_guy = self._parent.children()[last_index]
self._command_number -= 1
last_guy.setParent(None)
last_guy.setObjectName(None)
return last_guy
