詳解pyqt5 動畫在QThread線程中無法運行問題

2020-01-04 15:11:41

字體：大中小

來源：轉載

供稿：網友

自己做了一個tcp工具，在學習動畫的時候踩了坑，需求是根據上線變綠色，離線變灰色，如果連接斷開了，則變為灰色

問題現象：

pyqt5,QThread,線程,QThread線程,動畫

可以看到點擊“連接”，“離線”的時候動畫是正常的，但是當tcp超時斷開后，雖然離線按鈕變為連接了，卻沒有執行離線動畫

關鍵源代碼如下

class BSJTcpThread(QtCore.QThread):  recv_signal = QtCore.pyqtSignal(str)  send_signal = QtCore.pyqtSignal(str)  def __init__(self, socketcp, onBtn, heartcheck, senBtn, scene):    super().__init__()    self.s = socketcp    self.yqtool = Bianlifunction()    self.onBtn = onBtn    self.heartcheck = heartcheck    self.sendBtn = senBtn    self.scene1 = scene  def run(self):    """線程"""    global stopsingle    stopsingle = 0    while 1:      btcpreceive = self.s.recv(1024)      tcpreceive1 = str(binascii.b2a_hex(btcpreceive), encoding="utf-8")      tcpreceive = ""      i = 0      while i < len(tcpreceive1) - 1: # 十六進制數據處理,兩個字節隔開        if i == len(tcpreceive1) - 2:          tcpreceive += tcpreceive1[i:i + 2]          i += 2        else:          tcpreceive += tcpreceive1[i:i + 2] + " "          i += 2      if tcpreceive == "":        stopsingle = 1        self.s.shutdown(2)        self.s.close()        self.onBtn.setText("連接")        self.scene1.offlineCol.start() # 啟動離線動畫        self.heartcheck.setChecked(False)        self.heartcheck.setVisible(False)        self.sendBtn.setDisabled(True)      else:        self.recv_signal.emit(tcpreceive)      if stopsingle == 1:        break

然后再啟動線程

      self.tcpth = BSJTcpThread(self.s, self.onBtn, self.heartcheck, self.sendBtn, self.scene)      self.tcpth.recv_signal.connect(self.fillrecvmsg)      self.tcpth.send_signal.connect(self.fillsendmsg)      self.tcpth.start()

問題點：

經過谷爹搜索，終于找到了問題原因詳見https://stackoverflow.com/questions/44328750/pyqt-qgraphicscene-move-item-in-background-thread

大致原因就是QGraphics Scene 不是一個安全的線程對象，我們不能直接在線程中去改變主程序的狀態，我們必須通過信號的方式去更新QGraphics

解決方法：

首先，我們編輯一個信號方法

  def threadAnimate(self, message):    if message == "1":      self.scene.offlineCol.start()

然后添加相關信號槽

self.tcpth = BSJTcpThread(self.s, self.onBtn, self.heartcheck, self.sendBtn)      self.tcpth.recv_signal.connect(self.fillrecvmsg)      self.tcpth.send_signal.connect(self.fillsendmsg)      self.tcpth.animate_signal.connect(self.threadAnimate) # 添加一個動畫信號      self.tcpth.start()

在線程中發出離線動畫的信號

class BSJTcpThread(QtCore.QThread):  recv_signal = QtCore.pyqtSignal(str)  send_signal = QtCore.pyqtSignal(str)  animate_signal = QtCore.pyqtSignal(str)  def __init__(self, socketcp, onBtn, heartcheck, senBtn):    super().__init__()    self.s = socketcp    self.yqtool = Bianlifunction()    self.onBtn = onBtn    self.heartcheck = heartcheck    self.sendBtn = senBtn  def run(self):    """線程"""    global stopsingle    stopsingle = 0    while 1:      btcpreceive = self.s.recv(1024)      tcpreceive1 = str(binascii.b2a_hex(btcpreceive), encoding="utf-8")      tcpreceive = ""      i = 0      while i < len(tcpreceive1) - 1: # 十六進制數據處理,兩個字節隔開        if i == len(tcpreceive1) - 2:          tcpreceive += tcpreceive1[i:i + 2]          i += 2        else:          tcpreceive += tcpreceive1[i:i + 2] + " "          i += 2      if tcpreceive == "":        stopsingle = 1        self.s.shutdown(2)        self.s.close()        self.onBtn.setText("連接")        self.animate_signal.emit("1")        self.heartcheck.setChecked(False)        self.heartcheck.setVisible(False)        self.sendBtn.setDisabled(True)      else:        self.recv_signal.emit(tcpreceive)      if stopsingle == 1:        break

然后就可以了，這個和QThread多線程收發消息原理一樣

pyqt5,QThread,線程,QThread線程,動畫