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我需要能够从不是由用户交互（即通过进程完成）生成的信号（或等效的东西）更改 QStateMachine 的状态。此示例重定向用户生成的信号以演示该想法，但尚未起作用。在这里，按钮信号会触发我想用于转换的其他信号。这里的状态B1 <-> B2是按下Bi -> Bj按钮时重定向信号的位置bi。

QStateMachine 文档似乎只涵盖了基于按钮直接信号的转换，我无法推断出使用任何信号的更一般情况（即我创建的信号）。

import sys
from PySide2.QtCore import Qt, QStateMachine, QState, Signal as QSignal
from PySide2.QtWidgets import QApplication, QMainWindow, QPushButton, QVBoxLayout, QWidget

class MainWindow(QMainWindow):
    
    def __init__(self):
        QMainWindow.__init__(self)

        self.w = QWidget()
        self.setCentralWidget(self.w)
        
        l1 = QVBoxLayout()
        self.b1 = QPushButton("B1", self.w)
        self.b1.pressed.connect(self.b1Pressed)
        l1.addWidget(self.b1)
        self.b2  = QPushButton("B2", self.w)
        self.b2.pressed.connect(self.b2Pressed)
        l1.addWidget(self.b2)
        
        self.w .setLayout(l1)
        
        self.setupStateMachine()
        self.show()

    def b1Pressed(self):
        print("b1 pressed")
        self._b1Pressed.emit()
        
    def b2Pressed(self):
        print("b2 pressed")
        self._b2Pressed.emit()
            
    def setupStateMachine(self):
        
        self._b1Pressed = QSignal()
        self._b2Pressed = QSignal()
        
        self.sm = QStateMachine()
        
        self.B1 = QState()
        self.B1.assignProperty(self.b1, "enabled", True)
        self.B1.assignProperty(self.b2, "enabled", False)
        self.sm.addState(self.B1)

        self.B2 = QState()
        self.B2.assignProperty(self.b1, "enabled", False)
        self.B2.assignProperty(self.b2, "enabled", True)
        self.sm.addState(self.B2)
        
        # The point of it all:
        # change states from a signal (or program generated event)
        self.B1.addTransition(self._b1Pressed, self.B2)
        self.B2.addTransition(self._b2Pressed, self.B1)

if __name__ == '__main__':

    app = QApplication(sys.argv)
    window = MainWindow()
    sys.exit(app.exec_())
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1 回答 1

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您的代码存在以下问题：

  • 信号没有被声明为类的属性，而是在方法的同一级别。
  • 您尚未建立初始状态。
  • 您尚未启动 QStateMachine。
class MainWindow(QMainWindow):
    _b1Pressed = QSignal()
    _b2Pressed = QSignal()

    def __init__(self):
        QMainWindow.__init__(self)

        self.w = QWidget()
        self.setCentralWidget(self.w)

        l1 = QVBoxLayout()
        self.b1 = QPushButton("B1", self.w)
        self.b1.pressed.connect(self.b1Pressed)
        l1.addWidget(self.b1)
        self.b2 = QPushButton("B2", self.w)
        self.b2.pressed.connect(self.b2Pressed)
        l1.addWidget(self.b2)

        self.w.setLayout(l1)

        self.setupStateMachine()
        self.show()

    def b1Pressed(self):
        print("b1 pressed")
        self._b1Pressed.emit()

    def b2Pressed(self):
        print("b2 pressed")
        self._b2Pressed.emit()

    def setupStateMachine(self):

        self.sm = QStateMachine()

        self.B1 = QState()
        self.B1.assignProperty(self.b1, "enabled", True)
        self.B1.assignProperty(self.b2, "enabled", False)
        self.sm.addState(self.B1)

        self.B2 = QState()
        self.B2.assignProperty(self.b1, "enabled", False)
        self.B2.assignProperty(self.b2, "enabled", True)
        self.sm.addState(self.B2)

        # The point of it all:
        # change states from a signal (or program generated event)
        self.B1.addTransition(self._b1Pressed, self.B2)
        self.B2.addTransition(self._b2Pressed, self.B1)

        self.sm.setInitialState(self.B1)
        self.sm.start()
于 2020-09-29T03:40:55.137 回答