python中logging内容展示在pyqt多线程问题

Question

stackoverflow上找到了logging的处理

但是照搬原代码，会提示

QObject::connect: Cannot queue arguments of type 'QTextBlock'
(Make sure 'QTextBlock' is registered using qRegisterMetaType().)
QObject::connect: Cannot queue arguments of type 'QTextCursor'
(Make sure 'QTextCursor' is registered using qRegisterMetaType().)

照着去搜索，找到了较为安全的修改用户界面的方式是向UI窗口发送信号signal

综合一下，代码如下

class MyThead(QtCore.QThread):
    updated = QtCore.pyqtSignal(str)
    
    def __init__(self, mainUI, msg):
        super().__init__()
        self.updated.connect(mainUI.plainTextEdit.appendPlainText)
        self.msg = msg

    def run(self):
        self.updated.emit(self.msg)

class QPlainTextEditLogger(logging.Handler):

    def __init__(self, mainUI):
        super().__init__()
        self.mainUI = mainUI

    def emit(self, record):
        msg = self.format(record)
        _thread = MyThead(self.mainUI, msg)
        _thread.start()

代码无法执行，窗口直接销毁，无任何报错