QObject ¶

函数 ¶

虚函数 ¶

槽 ¶

信号 ¶

静态函数 ¶

线程倾向性 ¶

A QObject instance is said to have a 线程倾向性 , or that it lives in a certain thread. When a QObject 接收 queued signal 或 posted event , the slot or event handler will run in the thread that the object lives in.

注意

若 QObject has no thread affinity (that is, if thread() returns zero), or if it lives in a thread that has no running event loop, then it cannot receive queued signals or posted events.

默认情况下， QObject lives in the thread in which it is created. An object’s thread affinity can be queried using thread() and changed using moveToThread() .

所有 QObject 必须活在如其父级的相同线程内。因此：

• setParent() will fail if the two QObjects involved live in different threads.

• 当 QObject is moved to another thread, all its children will be automatically moved too.

• moveToThread() will fail if the QObject has a parent.

• If QObjects are created within run() , they cannot become children of the QThread object because the QThread does not live in the thread that calls run() .

注意

A QObject ‘s member variables do not automatically become its children. The parent-child relationship must be set by either passing a pointer to the child’s 构造函数 , or by calling setParent() . Without this step, the object’s member variables will remain in the old thread when moveToThread() 被调用。

不拷贝构造函数或赋值运算符 ¶

QObject has neither a copy constructor nor an assignment operator. This is by design. Actually, they are declared, but in a private section with the macro Q_DISABLE_COPY() . In fact, all Qt classes derived from QObject (direct or indirect) use this macro to declare their copy constructor and assignment operator to be private. The reasoning is found in the discussion on Identity vs Value on the Qt 对象模型 页面。

The main consequence is that you should use pointers to QObject (or to your QObject subclass) where you might otherwise be tempted to use your QObject subclass as a value. For example, without a copy constructor, you can’t use a subclass of QObject as the value to be stored in one of the container classes. You must store pointers.

自动连接 ¶

Qt’s meta-object system provides a mechanism to automatically connect signals and slots between QObject subclasses and their children. As long as objects are defined with suitable object names, and slots follow a simple naming convention, this connection can be performed at run-time by the connectSlotsByName() 函数。

uic generates code that invokes this function to enable auto-connection to be performed between widgets on forms created with Qt Designer . More information about using auto-connection with Qt Designer is given in the Using a Designer UI File in Your Application section of the Qt Designer 手册。

动态特性 ¶

From Qt 4.2, dynamic properties can be added to and removed from QObject instances at run-time. Dynamic properties do not need to be declared at compile-time, yet they provide the same advantages as static properties and are manipulated using the same API - using property() to read them and setProperty() to write them.

From Qt 4.3, dynamic properties are supported by Qt Designer, and both standard Qt widgets and user-created forms can be given dynamic properties.

国际化 (I18n) ¶

所有 QObject subclasses support Qt’s translation features, making it possible to translate an application’s user interface into different languages.

To make user-visible text translatable, it must be wrapped in calls to the tr() function. This is explained in detail in the Writing Source Code for Translation document.

另请参阅

QMetaObject QPointer QObjectCleanupHandler Q_DISABLE_COPY() 对象树 & 所有权

class QObject ( [ parent=None ] ) ¶

param parent

QObject

构造对象采用父级对象 parent .

The parent of an object may be viewed as the object’s owner. For instance, a dialog box is the parent of the OK and Cancel buttons it contains.

父级对象的析构函数会销毁所有子级对象。

设置 parent to None constructs an object with no parent. If the object is a widget, it will become a top-level window.

另请参阅

parent() findChild() findChildren()

PySide2.QtCore.QObject. blockSignals ( b ) ¶

参数

b – bool

返回类型

bool

若 block 为 true，阻塞由此对象发射的信号 (即：发射信号不会援引与其连接的任何东西)。若 block 为 false，不会发生这种阻塞。

返回值是先前值的 signalsBlocked() .

注意： destroyed() signal will be emitted even if the signals for this object have been blocked.

当被阻塞时发出的信号，不会被缓冲。

另请参阅

signalsBlocked() QSignalBlocker

PySide2.QtCore.QObject. childEvent ( event ) ¶

参数

event – QChildEvent

可以在子类中重实现此事件处理程序以接收子级事件。事件被传入 event 参数。

ChildAdded and ChildRemoved events are sent to objects when children are added or removed. In both cases you can only rely on the child being a QObject ，或者若 isWidgetType() 返回 true ， QWidget . (This is because, in the ChildAdded case, the child is not yet fully constructed, and in the ChildRemoved case it might have been destructed already).

ChildPolished events are sent to widgets when children are polished, or when polished children are added. If you receive a child polished event, the child’s construction is usually completed. However, this is not guaranteed, and multiple polish events may be delivered during the execution of a widget’s constructor.

For every child widget, you receive one ChildAdded event, zero or more ChildPolished events, and one ChildRemoved 事件。

ChildPolished event is omitted if a child is removed immediately after it is added. If a child is polished several times during construction and destruction, you may receive several child polished events for the same child, each time with a different virtual table.

另请参阅

event()

PySide2.QtCore.QObject. children ( ) ¶

返回类型

返回子级对象的列表。 QObjectList 类被定义于 <QObject> 头文件，如下所示：

第一添加子级是 first 对象在列表中，且最后添加子级是 last 对象在列表中，即：新子级被追加在末尾。

注意：列表次序改变，当 QWidget 子级 raised or lowered 。被提升 Widget 变为最后列表对象，被降低 Widget 变为第一列表对象。

另请参阅

findChild() findChildren() parent() setParent()

static PySide2.QtCore.QObject. connect ( arg__1 , arg__2 , arg__3 [ , type=Qt.AutoConnection ] ) ¶

参数

• arg__1 – QObject

• arg__2 – str

• arg__3 – PyCallable

• type – ConnectionType

返回类型

bool

static PySide2.QtCore.QObject. connect ( sender , signal , receiver , 方法 [ , type=Qt.AutoConnection ] ) ¶

参数

• sender – QObject

• signal – QMetaMethod

• receiver – QObject

• 方法 – QMetaMethod

• type – ConnectionType

返回类型

Connection

static PySide2.QtCore.QObject. connect ( sender , signal , receiver , member [ , type=Qt.AutoConnection ] ) ¶

参数

• sender – QObject

• signal – str

• receiver – QObject

• member – str

• type – ConnectionType

返回类型

Connection

Creates a connection of the given type 从 signal 在 sender object to the 方法 在 receiver object. Returns a handle to the connection that can be used to disconnect it later.

必须使用 SIGNAL() and SLOT() 宏当指定 signal 和 方法 ，例如：

label = QLabel()
scrollBar = QScrollBar()
QObject.connect(scrollBar, SIGNAL('valueChanged(int)'),
                 label, SLOT('setNum(int)'));
# or scrollBar.valueChanged.connect(label.setNum)
												

This example ensures that the label always displays the current scroll bar value. Note that the signal and slots parameters must not contain any variable names, only the type. E.g. the following would not work and return false:

// WRONG
QObject.connect(scrollBar, SIGNAL('valueChanged(int value)'),
                 label, SLOT('setNum(int value)'));
												

A signal can also be connected to another signal:

class MyWidget(QWidget):
    def __init__(self):
        myButton = QPushButton(self)
        myButton.clicked.connect(self.buttonClicked)
												

In this example, the MyWidget constructor relays a signal from a private member variable, and makes it available under a name that relates to MyWidget .

A signal can be connected to many slots and signals. Many signals can be connected to one slot.

If a signal is connected to several slots, the slots are activated in the same order in which the connections were made, when the signal is emitted.

The function returns a Connection that represents a handle to a connection if it successfully connects the signal to the slot. The connection handle will be invalid if it cannot create the connection, for example, if QObject is unable to verify the existence of either signal or 方法 , or if their signatures aren’t compatible. You can check if the handle is valid by casting it to a bool.

By default, a signal is emitted for every connection you make; two signals are emitted for duplicate connections. You can break all of these connections with a single disconnect() call. If you pass the UniqueConnection type , the connection will only be made if it is not a duplicate. If there is already a duplicate (exact same signal to the exact same slot on the same objects), the connection will fail and connect will return an invalid Connection .

注意

Qt::UniqueConnections do not work for lambdas, non-member functions and functors; they only apply to connecting to member functions.

可选 type parameter describes the type of connection to establish. In particular, it determines whether a particular signal is delivered to a slot immediately or queued for delivery at a later time. If the signal is queued, the parameters must be of types that are known to Qt’s meta-object system, because Qt needs to copy the arguments to store them in an event behind the scenes. If you try to use a queued connection and get the error message

QObject.connect: Cannot queue arguments of type 'MyType'
(Make sure 'MyType' is registered using qRegisterMetaType().)
												

call qRegisterMetaType() to register the data type before you establish the connection.

另请参阅

disconnect() sender() qRegisterMetaType() Q_DECLARE_METATYPE() Differences between String-Based and Functor-Based Connections

PySide2.QtCore.QObject. connect ( sender , signal , member [ , type=Qt.AutoConnection ] ) ¶

参数

• sender – QObject

• signal – str

• member – str

• type – ConnectionType

返回类型

Connection

此函数重载 connect() .

Connects signal 从 sender object to this object’s 方法 .

相当于 connect( sender , signal , this , 方法 , type ).

Every connection you make emits a signal, so duplicate connections emit two signals. You can break a connection using disconnect() .

另请参阅

disconnect()

PySide2.QtCore.QObject. connect ( arg__1 , arg__2 [ , type=Qt.AutoConnection ] ) ¶

参数

• arg__1 – str

• arg__2 – PyCallable

• type – ConnectionType

返回类型

bool

PySide2.QtCore.QObject. connect ( arg__1 , arg__2 , arg__3 [ , type=Qt.AutoConnection ] ) ¶

参数

• arg__1 – str

• arg__2 – QObject

• arg__3 – str

• type – ConnectionType

返回类型

bool

PySide2.QtCore.QObject. connectNotify ( signal ) ¶

参数

signal – QMetaMethod

This virtual function is called when something has been connected to signal in this object.

If you want to compare signal with a specific signal, you can use fromSignal() as follows:

if QLatin1String(signal) == SIGNAL('valueChanged()'):
    # signal is valueChanged()
												

警告

This function violates the object-oriented principle of modularity. However, it might be useful when you need to perform expensive initialization only if something is connected to a signal.

警告

This function is called from the thread which performs the connection, which may be a different thread from the thread in which this object lives.

另请参阅

connect() disconnectNotify()

PySide2.QtCore.QObject. customEvent ( event ) ¶

参数

event – QEvent

This event handler can be reimplemented in a subclass to receive custom events. Custom events are user-defined events with a type value at least as large as the User item of the Type enum, and is typically a QEvent subclass. The event is passed in the event 参数。

另请参阅

event() QEvent

PySide2.QtCore.QObject. deleteLater ( ) ¶

安排删除此对象。

The object will be deleted when control returns to the event loop. If the event loop is not running when this function is called (e.g. is called on an object before exec() ), the object will be deleted once the event loop is started. If is called after the main event loop has stopped, the object will not be deleted. Since Qt 4.8, if is called on an object that lives in a thread with no running event loop, the object will be destroyed when the thread finishes.

注意：进入和离开新事件循环 (如，通过打开模态对话框) 会 not perform the deferred deletion; for the object to be deleted, the control must return to the event loop from which was called. This does not apply to objects deleted while a previous, nested event loop was still running: the Qt event loop will delete those objects as soon as the new nested event loop starts.

注意

多次调用此函数是安全的；当交付首个延迟删除事件时，对象的任何待决事件均将从事件队列中被移除。

另请参阅

destroyed() QPointer

PySide2.QtCore.QObject. destroyed ( [ object=None ] ) ¶

参数

object – QObject

PySide2.QtCore.QObject. disconnect ( receiver [ , member=None ] ) ¶

参数

• receiver – QObject

• member – str

返回类型

bool

此函数重载 disconnect() .

Disconnects all signals in this object from receiver ‘s 方法 .

A signal-slot connection is removed when either of the objects involved are destroyed.

PySide2.QtCore.QObject. disconnect ( signal , receiver , member ) ¶

参数

• signal – str

• receiver – QObject

• member – str

返回类型

bool

此函数重载 disconnect() .

Disconnects signal from 方法 of receiver .

A signal-slot connection is removed when either of the objects involved are destroyed.

PySide2.QtCore.QObject. disconnect ( arg__1 , arg__2 ) ¶

参数

• arg__1 – str

• arg__2 – PyCallable

返回类型

bool

static PySide2.QtCore.QObject. disconnect ( sender , signal , receiver , member ) ¶

参数

• sender – QObject

• signal – str

• receiver – QObject

• member – str

返回类型

bool

Disconnects signal in object sender from 方法 in object receiver 。返回 true if the connection is successfully broken; otherwise returns false .

A signal-slot connection is removed when either of the objects involved are destroyed.

is typically used in three ways, as the following examples demonstrate.

1. Disconnect everything connected to an object’s signals:

   disconnect(myObject, 0, 0, 0)
   														

   equivalent to the non-static overloaded function

   myObject.disconnect()
   														

2. Disconnect everything connected to a specific signal:

   disconnect(myObject, SIGNAL('mySignal()'), 0, 0)
   														

   equivalent to the non-static overloaded function

   myObject.disconnect(SIGNAL('mySignal()'))
   														

3. Disconnect a specific receiver:

   disconnect(myObject, 0, myReceiver, 0)
   														

   equivalent to the non-static overloaded function

   myObject.disconnect(myReceiver)
   														

None may be used as a wildcard, meaning “any signal”, “any receiving object”, or “any slot in the receiving object”, respectively.

sender 可能从不是 None . (You cannot disconnect signals from more than one object in a single call.)

若 signal is None , it disconnects receiver and 方法 from any signal. If not, only the specified signal is disconnected.

若 receiver is None , it disconnects anything connected to signal . If not, slots in objects other than receiver are not disconnected.

若 方法 is None , it disconnects anything that is connected to receiver . If not, only slots named 方法 will be disconnected, and all other slots are left alone. The 方法 必须是 None if receiver is left out, so you cannot disconnect a specifically-named slot on all objects.

另请参阅

connect()

static PySide2.QtCore.QObject. disconnect ( sender , signal , receiver , member ) ¶

参数

• sender – QObject

• signal – QMetaMethod

• receiver – QObject

• member – QMetaMethod

返回类型

bool

static PySide2.QtCore.QObject. disconnect ( arg__1 , arg__2 , arg__3 ) ¶

参数

• arg__1 – QObject

• arg__2 – str

• arg__3 – PyCallable

返回类型

bool

static PySide2.QtCore.QObject. disconnect ( arg__1 ) ¶

参数

arg__1 – Connection

返回类型

bool

Disconnect a connection.

若 connection is invalid or has already been disconnected, do nothing and return false.

另请参阅

connect()

PySide2.QtCore.QObject. disconnectNotify ( signal ) ¶

参数

signal – QMetaMethod

This virtual function is called when something has been disconnected from signal in this object.

见 connectNotify() for an example of how to compare signal with a specific signal.

If all signals were disconnected from this object (e.g., the signal argument to disconnect() was None ), is only called once, and the signal will be an invalid QMetaMethod ( isValid() 返回 false ).

警告

This function violates the object-oriented principle of modularity. However, it might be useful for optimizing access to expensive resources.

警告

This function is called from the thread which performs the disconnection, which may be a different thread from the thread in which this object lives. This function may also be called with a QObject internal mutex locked. It is therefore not allowed to re-enter any of any QObject functions from your reimplementation and if you lock a mutex in your reimplementation, make sure that you don’t call QObject functions with that mutex held in other places or it will result in a deadlock.

另请参阅

disconnect() connectNotify()

PySide2.QtCore.QObject. dumpObjectInfo ( ) ¶

将有关此对象的信号连接等信息转储到调试输出。

注意

在 Qt 5.9 之前，此函数不是 const。

另请参阅

dumpObjectTree()

PySide2.QtCore.QObject. dumpObjectTree ( ) ¶

将子级树转储到调试输出。

注意

在 Qt 5.9 之前，此函数不是 const。

另请参阅

dumpObjectInfo()

PySide2.QtCore.QObject. dynamicPropertyNames ( ) ¶

返回类型

Returns the names of all properties that were dynamically added to the object using setProperty() .

PySide2.QtCore.QObject. emit ( arg__1 , arg__2 ) ¶

参数

• arg__1 – str

• arg__2 – :class:``

返回类型

bool

PySide2.QtCore.QObject. event ( event ) ¶

参数

event – QEvent

返回类型

bool

此虚函数接收对象事件并返回 true，若事件 e 被识别并被处理。

The function can be reimplemented to customize the behavior of an object.

确保调用父级事件类实现，为所有未处理事件。

范例：

class MyClass : public QWidget
{
    Q_OBJECT
public:
    MyClass(QWidget *parent = nullptr);
    ~MyClass();
    bool event(QEvent* ev) override
    {
        if (ev->type() == QEvent::PolishRequest) {
            // overwrite handling of PolishRequest if any
            doThings();
            return true;
        } else  if (ev->type() == QEvent::Show) {
            // complement handling of Show if any
            doThings2();
            QWidget::event(ev);
            return true;
        }
        // Make sure the rest of events are handled
        return QWidget::event(ev);
    }
};
												

另请参阅

installEventFilter() timerEvent() sendEvent() postEvent()

PySide2.QtCore.QObject. eventFilter ( watched , event ) ¶

参数

• watched – QObject

• event – QEvent

返回类型

bool

过滤事件，若此对象已被安装成事件过滤器为 watched 对象。

在此函数的重实现中，若希望过滤 event 即：停止进一步处理，返回 true；否则返回 false。

范例：

class MainWindow(QMainWindow):
    def __init__(self):
        self.textEdit = QTextEdit()
        setCentralWidget(self.textEdit)
        textEdit.installEventFilter(self)
    def eventFilter(self, obj, event):
        if obj == textEdit:
            if event.type() == QEvent.KeyPress:
                keyEvent = event
                print("Ate key press", keyEvent.key())
                return true
            else:
                return false
        else:
            # pass the event on to the parent class
            return QMainWindow.eventFilter(self, obj, event)
												

Notice in the example above that unhandled events are passed to the base class’s function, since the base class might have reimplemented for its own internal purposes.

某些事件，如 ShortcutOverride 必须被明确接受 (通过调用 accept() ) 为阻止传播。

警告

若在此函数中删除接收者对象，确保返回 true。否则，Qt 将把事件转发给被删除对象，且程序可能崩溃。

另请参阅

installEventFilter()

PySide2.QtCore.QObject. findChild ( arg__1 [ , arg__2="" ] ) ¶

参数

• arg__1 – PyTypeObject

• arg__2 – unicode

返回类型

PyObject

To find the child of a certain QObject, the first argument of this function should be the child’s type, and the second the name of the child:

...
parent = QWidget()
...
# The first argument must be the child type
child1 = parent.findChild(QPushButton, "child_button")
child2 = parent.findChild(QWidget, "child_widget")
														

PySide2.QtCore.QObject. findChildren ( arg__1 , arg__2 ) ¶

参数

• arg__1 – PyTypeObject

• arg__2 – QRegExp

返回类型

PySequence

PySide2.QtCore.QObject. findChildren ( arg__1 [ , arg__2="" ] ) ¶

参数

• arg__1 – PyTypeObject

• arg__2 – unicode

返回类型

PySequence

Like the method findChild , the first parameter should be the child’s type.

PySide2.QtCore.QObject. 继承 ( classname ) ¶

参数

classname – str

返回类型

bool

返回 true 若此对象是类实例，继承 className 或 QObject 子类，继承 className ；否则返回 false .

类被认为继承本身。

范例：

timer = QTimer()                    # QTimer inherits QObject
timer.inherits("QTimer")            # returns true
timer.inherits("QObject")           # returns true
timer.inherits("QAbstractButton")   # returns false
# QLayout inherits QObject and QLayoutItem
layout = QLayout()
layout.inherits("QObject")          # returns true
layout.inherits("QLayoutItem")      # returns false
												

若为铸造目的需要确定对象是否为特定类的实例，考虑使用 qobject_cast <Type *>(object) instead.

另请参阅

metaObject() qobject_cast()

PySide2.QtCore.QObject. installEventFilter ( filterObj ) ¶

参数

filterObj – QObject

安装事件过滤器 filterObj 在此对象。例如：

monitoredObj.installEventFilter(filterObj)
												

An event filter is an object that receives all events that are sent to this object. The filter can either stop the event or forward it to this object. The event filter filterObj 接收事件凭借其 eventFilter() function. The eventFilter() function must return true if the event should be filtered, (i.e. stopped); otherwise it must return false.

If multiple event filters are installed on a single object, the filter that was installed last is activated first.

Here’s a KeyPressEater class that eats the key presses of its monitored objects:

class KeyPressEater(QObject):
    def eventFilter(self, obj, event):
        if event.type() == QEvent.KeyPress:
            print("Ate key press", event.key())
            return True
        else:
            # standard event processing
            return QObject.eventFilter(self, obj, event)
												

And here’s how to install it on two widgets:

keyPressEater = KeyPressEater(self)
pushButton = QPushButton(self)
listView = QListView(self)
pushButton.installEventFilter(keyPressEater)
listView.installEventFilter(keyPressEater)
												

QShortcut class, for example, uses this technique to intercept shortcut key presses.

警告

If you delete the receiver object in your eventFilter() function, be sure to return true. If you return false, Qt sends the event to the deleted object and the program will crash.

Note that the filtering object must be in the same thread as this object. If filterObj is in a different thread, this function does nothing. If either filterObj or this object are moved to a different thread after calling this function, the event filter will not be called until both objects have the same thread affinity again (it is not removed).

另请参阅

removeEventFilter() eventFilter() event()

PySide2.QtCore.QObject. isSignalConnected ( signal ) ¶

参数

signal – QMetaMethod

返回类型

bool

返回 true 若 signal is connected to at least one receiver, otherwise returns false .

signal must be a signal member of this object, otherwise the behaviour is undefined.

static const QMetaMethod valueChangedSignal = QMetaMethod::fromSignal(&MyObject::valueChanged);
if (isSignalConnected(valueChangedSignal)) {
    QByteArray data;
    data = get_the_value();       // expensive operation
    emit valueChanged(data);
}
												

As the code snippet above illustrates, you can use this function to avoid emitting a signal that nobody listens to.

警告

This function violates the object-oriented principle of modularity. However, it might be useful when you need to perform expensive initialization only if something is connected to a signal.

PySide2.QtCore.QObject. isWidgetType ( ) ¶

返回类型

bool

返回 true if the object is a widget; otherwise returns false .

调用此函数相当于调用 inherits("QWidget") ，除了它更快。

PySide2.QtCore.QObject. isWindowType ( ) ¶

返回类型

bool

返回 true 若对象是窗口；否则返回 false .

调用此函数相当于调用 inherits("QWindow") ，除了它更快。

PySide2.QtCore.QObject. killTimer ( id ) ¶

参数

id – int

杀除计时器采用计时器标识符， id .

计时器标识符被返回通过 startTimer() when a timer event is started.

另请参阅

timerEvent() startTimer()

PySide2.QtCore.QObject. metaObject ( ) ¶

返回类型

QMetaObject

返回指向此对象的元对象的指针。

A meta-object contains information about a class that inherits QObject , e.g. class name, superclass name, properties, signals and slots. Every QObject subclass that contains the Q_OBJECT macro will have a meta-object.

The meta-object information is required by the signal/slot connection mechanism and the property system. The inherits() function also makes use of the meta-object.

If you have no pointer to an actual object instance but still want to access the meta-object of a class, you can use staticMetaObject .

范例：

obj = QPushButton()
obj.metaObject().className()                # returns "QPushButton"
QPushButton.staticMetaObject.className()    # returns "QPushButton"
												

另请参阅

staticMetaObject

PySide2.QtCore.QObject. moveToThread ( thread ) ¶

参数

thread – QThread

更改此对象及其子级的线程亲缘关系。对象无法被移动，若它有父级。事件处理将继续在 targetThread .

To move an object to the main thread, use instance() to retrieve a pointer to the current application, and then use thread() to retrieve the thread in which the application lives. For example:

myObject.moveToThread(QApplication.instance().thread())
												

若 targetThread is None , all event processing for this object and its children stops, as they are no longer associated with any thread.

Note that all active timers for the object will be reset. The timers are first stopped in the current thread and restarted (with the same interval) in the targetThread . As a result, constantly moving an object between threads can postpone timer events indefinitely.

A ThreadChange event is sent to this object just before the thread affinity is changed. You can handle this event to perform any special processing. Note that any new events that are posted to this object will be handled in the targetThread , provided it is not None : when it is None , no event processing for this object or its children can happen, as they are no longer associated with any thread.

警告

此函数是 not thread-safe; the current thread must be same as the current thread affinity. In other words, this function can only “push” an object from the current thread to another thread, it cannot “pull” an object from any arbitrary thread to the current thread. There is one exception to this rule however: objects with no thread affinity can be “pulled” to the current thread.

另请参阅

thread()

PySide2.QtCore.QObject. objectName ( ) ¶

返回类型

unicode

另请参阅

setObjectName()

PySide2.QtCore.QObject. parent ( ) ¶

返回类型

QObject

返回指向父级对象的指针。

另请参阅

setParent() children()

PySide2.QtCore.QObject. 特性 ( name ) ¶

参数

name – str

返回类型

object

Returns the value of the object’s name 特性。

返回的变体是无效的，若没有这样的特性存在。

所有可用特性的有关信息，提供透过 metaObject() and dynamicPropertyNames() .

另请参阅

setProperty() isValid() metaObject() dynamicPropertyNames()

PySide2.QtCore.QObject. receivers ( signal ) ¶

参数

signal – str

返回类型

int

返回接收者数为连接到 signal .

Since both slots and signals can be used as receivers for signals, and the same connections can be made many times, the number of receivers is the same as the number of connections made from this signal.

When calling this function, you can use the SIGNAL() macro to pass a specific signal:

if receivers(SIGNAL('valueChanged()')) > 0:
    data = get_the_value()  # expensive operation
    self.valueChanged(data)
												

警告

This function violates the object-oriented principle of modularity. However, it might be useful when you need to perform expensive initialization only if something is connected to a signal.

另请参阅

isSignalConnected()

static PySide2.QtCore.QObject. registerUserData ( ) ¶

返回类型

uint

注意

此函数被弃用。

PySide2.QtCore.QObject. removeEventFilter ( obj ) ¶

参数

obj – QObject

Removes an event filter object obj from this object. The request is ignored if such an event filter has not been installed.

All event filters for this object are automatically removed when this object is destroyed.

It is always safe to remove an event filter, even during event filter activation (i.e. from the eventFilter() 函数)。

另请参阅

installEventFilter() eventFilter() event()

PySide2.QtCore.QObject. sender ( ) ¶

返回类型

QObject

返回发送信号的对象指针，若在由信号激活的槽中调用；否则它返回 None . The pointer is valid only during the execution of the slot that calls this function from this object’s thread context.

The pointer returned by this function becomes invalid if the sender is destroyed, or if the slot is disconnected from the sender’s signal.

警告

此函数违反模块化面向对象原则。不管怎样，访问发送器可能很有用，当多个信号连接到单个槽时。

警告

如上所述，此函数的返回值无效，当槽被调用凭借 DirectConnection from a thread different from this object’s thread. Do not use this function in this type of scenario.

另请参阅

senderSignalIndex()

PySide2.QtCore.QObject. senderSignalIndex ( ) ¶

返回类型

int

Returns the meta-method index of the signal that called the currently executing slot, which is a member of the class returned by sender() . If called outside of a slot activated by a signal, -1 is returned.

For signals with default parameters, this function will always return the index with all parameters, regardless of which was used with connect() . For example, the signal destroyed(QObject *obj = \nullptr) will have two different indexes (with and without the parameter), but this function will always return the index with a parameter. This does not apply when overloading signals with different parameters.

警告

This function violates the object-oriented principle of modularity. However, getting access to the signal index might be useful when many signals are connected to a single slot.

警告

The return value of this function is not valid when the slot is called via a DirectConnection from a thread different from this object’s thread. Do not use this function in this type of scenario.

另请参阅

sender() indexOfSignal() method()

PySide2.QtCore.QObject. setObjectName ( name ) ¶

参数

name – unicode

另请参阅

objectName()

PySide2.QtCore.QObject. setParent ( parent ) ¶

参数

parent – QObject

使对象子级 parent .

另请参阅

parent() children()

PySide2.QtCore.QObject. setProperty ( name , value ) ¶

参数

• name – str

• value – object

返回类型

bool

Sets the value of the object’s name 特性到 value .

If the property is defined in the class using Q_PROPERTY then true is returned on success and false otherwise. If the property is not defined using Q_PROPERTY , and therefore not listed in the meta-object, it is added as a dynamic property and false is returned.

所有可用特性的有关信息，提供透过 metaObject() and dynamicPropertyNames() .

Dynamic properties can be queried again using property() and can be removed by setting the property value to an invalid QVariant . Changing the value of a dynamic property causes a QDynamicPropertyChangeEvent to be sent to the object.

注意

Dynamic properties starting with “_q_” are reserved for internal purposes.

另请参阅

property() metaObject() dynamicPropertyNames() write()

PySide2.QtCore.QObject. signalsBlocked ( ) ¶

返回类型

bool

返回 true 若信号被阻塞；否则返回 false .

信号不被阻塞，默认情况下。

另请参阅

blockSignals() QSignalBlocker

PySide2.QtCore.QObject. startTimer ( interval [ , timerType=Qt.CoarseTimer ] ) ¶

参数

• interval – int

• timerType – TimerType

返回类型

int

Starts a timer and returns a timer identifier, or returns zero if it could not start a timer.

A timer event will occur every interval milliseconds until killTimer() is called. If interval is 0, then the timer event occurs once every time there are no more window system events to process.

虚拟 timerEvent() function is called with the QTimerEvent event parameter class when a timer event occurs. Reimplement this function to get timer events.

If multiple timers are running, the timerId() can be used to find out which timer was activated.

范例：

class MyObject(QObject):
    def __init__(self, parent):
        QObject.__init__(self, parent)
        self.startTimer(50)         # 50-millisecond timer
        self.startTimer(1000)       # 1-second timer
        self.startTimer(60000)      # 1-minute timer
    def timerEvent(self, event):
        print("Timer ID:", event.timerId())
												

注意： QTimer ‘s accuracy depends on the underlying operating system and hardware. The timerType argument allows you to customize the accuracy of the timer. See TimerType for information on the different timer types. Most platforms support an accuracy of 20 milliseconds; some provide more. If Qt is unable to deliver the requested number of timer events, it will silently discard some.

QTimer class provides a high-level programming interface with single-shot timers and timer signals instead of events. There is also a QBasicTimer class that is more lightweight than QTimer and less clumsy than using timer IDs directly.

另请参阅

timerEvent() killTimer() singleShot()

PySide2.QtCore.QObject. thread ( ) ¶

返回类型

QThread

返回对象所在的线程。

另请参阅

moveToThread()

PySide2.QtCore.QObject. timerEvent ( event ) ¶

参数

event – QTimerEvent

This event handler can be reimplemented in a subclass to receive timer events for the object.

QTimer provides a higher-level interface to the timer functionality, and also more general information about timers. The timer event is passed in the event 参数。

另请参阅

startTimer() killTimer() event()

PySide2.QtCore.QObject. tr ( arg__1 [ , arg__2=0 [ , arg__3=-1 ] ] ) ¶

参数

• arg__1 – str

• arg__2 – str

• arg__3 – int

返回类型

unicode