在PyQt5中使用QThread的時候,要注意把所有QThread的對象在主類中的init(或者放在所有類函數的外面)中進行實例化,不然可能在多個QThread互相調用的時候,emit重複的信號。一般比較正確的寫法如下所示,基本照着這種框架搭建都是沒問題的。
# -*- coding: utf-8 -*-
import sys
import time
from PyQt5.QtWidgets import *
from PyQt5.QtCore import *
class MainUi(QWidget):
def __init__(self):
super(MainUi, self).__init__()
self.resize(400, 200)
self.setWindowTitle('QThread例子')
# 實例化多線程對象
self.thread = Worker()
# 實例化列表控件與按鈕控件
self.listFile = QListWidget()
self.btnStart = QPushButton('開始')
self.btn_over = QPushButton('結束')
# 把控件放置在柵格佈局中
layout = QGridLayout(self)
layout.addWidget(self.listFile, 0, 0, 1, 2)
layout.addWidget(self.btnStart, 1, 0)
layout.addWidget(self.btn_over, 1, 1)
# 信號與槽函數的連接
self.btnStart.clicked.connect(self.slotStart)
self.btn_over.clicked.connect(self.slot_btn_over)
# 建立線程信號的槽連接
self.thread.trigger.connect(self.slotAdd)
def slotAdd(self, msg):
print(msg)
if int(msg) % 2 == 0:
self.listFile.addItem(msg)
else:
pass
self.thread.exit()
def slotStart(self):
self.btnStart.setEnabled(False)
self.thread.start()
def slot_btn_over(self):
self.btnStart.setEnabled(True)
self.thread.terminate()
self.thread.num = 0
class Worker(QThread):
trigger = pyqtSignal(str)
num = 0
def __init__(self):
super(Worker, self).__init__()
def run(self):
while True:
print('num= ', self.num)
if self.num % 2 == 0:
self.trigger.emit(str(50))
elif self.num == 200:
self.num = 0
else:
pass
time.sleep(0.1)
self.num += 1
if __name__ == '__main__':
app = QApplication(sys.argv)
w = MainUi()
w.show()
sys.exit(app.exec_())