最近在用qt做项目的时候，由于项目只有一个线程，所以在处理图片的时候，视频流就卡住了。以下用一个例子简单记录如何解决新建子线程时传参和子线程返回数据到主线程的问题。

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UI代码（untitled.py）

from PyQt5 import QtCore, QtGui, QtWidgetsclass Ui_Form(object):def setupUi(self, Form):Form.setObjectName("Form")Form.resize(400, 300)self.lineEdit = QtWidgets.QLineEdit(Form)self.lineEdit.setGeometry(QtCore.QRect(140, 80, 113, 21))self.lineEdit.setObjectName("lineEdit")self.pushButton = QtWidgets.QPushButton(Form)self.pushButton.setGeometry(QtCore.QRect(150, 150, 93, 28))self.pushButton.setObjectName("pushButton")self.retranslateUi(Form)QtCore.QMetaObject.connectSlotsByName(Form)def retranslateUi(self, Form):_translate = QtCore.QCoreApplication.translateForm.setWindowTitle(_translate("Form", "Form"))self.pushButton.setText(_translate("Form", "test"))

槽函数代码（slot.py）

from PyQt5.QtWidgets import QWidget
from PyQt5.QtCore import QThread, pyqtSignal
from untitled import Ui_Form# 子线程类
class TestThread(QThread):'''声明用于传递数据到主线程的信号并指定传输的数据类型，此信号不能在__init__方法中声明，传递的数据类型支持标准的python数据类型，如字符串、日期、布尔类型，数字，列表，元组和字典。'''testsignal= pyqtSignal(str)def __init__(self, msg):super(TestThread, self).__init__()self.msg = msgdef __del__(self):self.wait()def run(self):self.msg = 'This is a ' + self.msg# 发射信号self.testsignal.emit(self.msg)class Slot(QWidget, Ui_Form):def __init__(self, parent=None):super().__init__(parent)self.ui = Ui_Formself.setupUi(self)self.pushButton.clicked.connect(self.text)def text(self):# 新建有参数的子线程self.thread = TestThread('test')# 连接信号和用于更新ui的函数self.thread.testsignal.connect(self.showText)self.thread.start()def showText(self, msg):self.lineEdit.setText(msg)

运行代码（main.py）

import sys
from qtpy import QtWidgets
from slot import Slotapp = QtWidgets.QApplication(sys.argv)
a = Slot()
a.show()
sys.exit(app.exec_())

参考了这篇博客的内容：https://blog.csdn.net/wuwei_201/article/details/104720386