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传统写法
import sys
from PySide2.QtWidgets import QApplication, QPushButton
from PySide2.QtCore import SIGNAL, QObject
def func():
print("func has been called!")
app = QApplication(sys.argv)
button = QPushButton("Call func")
QObject.connect(button, SIGNAL ('clicked()'), func)
button.show()
sys.exit(app.exec_())
这种写法很复杂，通过静态函数和两个宏来完成signal 和slot的对接所以一点页不不pythonic，官方不推荐的写法
新的写法
import sys
from PySide2.QtWidgets import QApplication, QPushButton
def func():
print("func has been called!")
app = QApplication(sys.argv)
button = QPushButton("Call func")
button.clicked.connect(func)
button.show()
sys.exit(app.exec_())
这个句法是官方推荐的。
自定义Signal 和Slot
下面定义Slot 和Signal 是最简单的
import sys
from PySide2 import QtCore, QtGui
# define a function that will be used as a slot
def sayHello():
print 'Hello world!'
app = QtGui.QApplication(sys.argv)
button = QtGui.QPushButton('Say hello!')
# connect the clicked signal to the sayHello slot
button.clicked.connect(sayHello)
button.show()
sys.exit(app.exec_())
下面展示了如何用Wrapper来定义Slot，并且Signal和Slot开始处理类型变量了
import sys
from PySide2.QtWidgets import QApplication, QPushButton
from PySide2.QtCore import QObject, Signal, Slot
app = QApplication(sys.argv)
# define a new slot that receives a string and has
# 'saySomeWords' as its name
@Slot(str)
def say_some_words(words):
print(words)
class Communicate(QObject):
# create a new signal on the fly and name it 'speak'
speak = Signal(str)
someone = Communicate()
# connect signal and slot
someone.speak.connect(say_some_words)
# emit 'speak' signal
someone.speak.emit("Hello everybody!")
下面是重载版本
import sys
from PySide2.QtWidgets import QApplication, QPushButton
from PySide2.QtCore import QObject, Signal, Slot
app = QApplication(sys.argv)
# define a new slot that receives a C 'int' or a 'str'
# and has 'saySomething' as its name
@Slot(int)
@Slot(str)
def say_something(stuff):
print(stuff)
class Communicate(QObject):
# create two new signals on the fly: one will handle
# int type, the other will handle strings
speak_number = Signal(int)
speak_word = Signal(str)
someone = Communicate()
# connect signal and slot properly
someone.speak_number.connect(say_something)
someone.speak_word.connect(say_something)
# emit each 'speak' signal
someone.speak_number.emit(10)
someone.speak_word.emit("Hello everybody!"))
pythinic版本的重载（我也第一次看见）
import sys
from PySide2.QtWidgets import QApplication, QPushButton
from PySide2.QtCore import QObject, Signal, Slot
app = QApplication(sys.argv)
# define a new slot that receives a C 'int' or a 'str'
# and has 'saySomething' as its name
@Slot(int)
@Slot(str)
def say_something(stuff):
print(stuff)
class Communicate(QObject):
# create two new signals on the fly: one will handle
# int type, the other will handle strings
speak = Signal((int,), (str,))
someone = Communicate()
# connect signal and slot. As 'int' is the default
# we have to specify the str when connecting the
# second signal
someone.speak.connect(say_something)
someone.speak[str].connect(say_something)
# emit 'speak' signal with different arguments.
# we have to specify the str as int is the default
someone.speak.emit(10)
someone.speak[str].emit("Hello everybody!")
一个对象发出信号
import sys
from PySide2.QtCore import QObject, Signal
# Must inherit QObject for signals
class Communicate(QObject):
speak = Signal()
def __init__(self):
super(Communicate, self).__init__()
self.speak.connect(self.say_hello)
def speaking_method(self):
self.speak.emit()
def say_hello(self):
print("Hello")
someone = Communicate()
someone.speaking_method()
注意： 类的实例才能发射信号 ，类是不可以发射信号的
# Erroneous: refers to class Communicate, not an instance of the class
Communicate.speak.connect(say_something)
# raises exception: AttributeError: 'PySide2.QtCore.Signal' object has no attribute 'connect'