PySide2信号与槽机制

1、信号与槽的两种写法
第一种情况：

from PySide2 import QtWidgets, QtCore
import sys
if __name__ == "__main__":
    app = QtWidgets.QApplication(sys.argv)
    widget = QtWidgets.QWidget()
    btn = QtWidgets.QPushButton(widget)
    btn.clicked.connect(widget.close)
    widget.show()
    sys.exit(app.exec_())

第二种情况：

from PySide2 import QtWidgets, QtCore
import sys
if __name__ == "__main__":
    app = QtWidgets.QApplication(sys.argv)
    widget = QtWidgets.QWidget()
    btn = QtWidgets.QPushButton(widget)
    QtCore.QObject.connect(btn,QtCore.SIGNAL("clicked()"),widget,QtCore.SLOT("close()"))
    widget.show()
    sys.exit(app.exec_())

2、自定义槽函数

from PySide2 import QtWidgets, QtCore
import sys 
if __name__ == "__main__":
    app = QtWidgets.QApplication(sys.argv)
    widget = QtWidgets.QWidget()
    btn = QtWidgets.QPushButton(widget)
    @QtCore.Slot()
    def changeTex():
        btn.setText("ok")
    btn.clicked.connect(changeTex)    
    widget.show()
    sys.exit(app.exec_())

3、带参数槽函数
（1）lambad写法：

from PySide2 import QtWidgets,QtCore
import sys  
class MyForm(QtWidgets.QWidget):  
    def __init__(self, parent=None):  
        super(MyForm, self).__init__(parent)
        button1 = QtWidgets.QPushButton(self)   
        button1.clicked.connect(lambda: self.on_button(1))  
    def on_button(self, n):  
        print('Button {0} clicked'.format(n))  
  
if __name__ == "__main__":  
    import sys  
    app = QtWidgets.QApplication(sys.argv)  
    form = MyForm()  
    form.show()  
    app.exec_()  

（2）使用functools里的partial函数。

from functools import partial 
from PySide2 import QtWidgets,QtCore
import sys  
class MyForm(QtWidgets.QWidget):  
    def __init__(self, parent=None):  
        super(MyForm, self).__init__(parent)
        button1 = QtWidgets.QPushButton(self)   
        button1.clicked.connect(partial(self.on_button, 1))  
    def on_button(self, n):  
        print('Button {0} clicked'.format(n))  

if __name__ == "__main__":  
    import sys  
    app = QtWidgets.QApplication(sys.argv)  
    form = MyForm()  
    form.show()  
    app.exec_()