QProcess PyQt5 TypeError

Question

我有一个使用大量 QProcess 的应用程序，有时同时使用两个进程运行。这就是为什么我有很多 readyReadStandardOutput.connect() 的功能。所以我的想法是为类似情况创建两个或三个 classes 并大量减少代码。我已经能够检查在这个问题中，有一个我喜欢的解决方案

还有一个：

我试图创建一个 class 可以帮助我从第一个 link 的 class 开始，但是我没有成功，因为它会产生错误

QObject::connect: Cannot connect ProcessOutputReader::produce_output(QString) to (null)::append_output(QString)
Traceback (most recent call last):
  File "process2.py", line 22, in funRun
    self.process.run_process()
  File "process2.py", line 40, in run_process
    self.process.produce_output.connect(self.append_output)
TypeError: connect() failed between ProcessOutputReader.produce_output[str] and append_output()

这是我的代码：

import sys
from PyQt5.QtWidgets import *
from PyQt5.QtGui import *
from PyQt5.QtCore import *


class windowProcess(QMainWindow):
    def __init__(self):
        super(windowProcess, self).__init__()
        self.setWindowTitle("Windows Process")
        self.resize(475, 253)
        self.btn_run = QPushButton("run",self)
        self.btn_run.setGeometry(388, 20, 75, 25)
        self.text_edit = QTextEdit(self)

        self.text_edit.setGeometry(20, 50, 441, 191)

        self.btn_run.clicked.connect(self.funRun)

    def funRun(self):
        self.process = myClassProcess()
        self.process.run_process()


    @pyqtSlot(str)
    def append_output(self, text):
        self.text_edit.append(text)

    @pyqtSlot(str)
    def append_error(self, text):
        self.text_edit.append(text)


class myClassProcess(object):
    def __init__(self, parent=None):
        self.info = []

    def run_process(self):        
        self.process = ProcessOutputReader()
        cmd = "ping www.google.com"
        self.process.produce_output.connect(self.append_output)
        self.process.produce_error.connect(self.append_error)
        self.process.start(cmd)

    @pyqtSlot(str)
    def append_output(self, text):
        print(text)
        self.info.append(text)
        #return text            

    @pyqtSlot(str)
    def append_error(self, text):
        self.info.append(text)
        #return text            

    def getInfo(self):
        print(self.info)


class ProcessOutputReader(QProcess):
    produce_output = pyqtSignal(str)
    produce_error = pyqtSignal(str)

    def __init__(self, parent=None):
        super().__init__(parent=parent)

        codec = QTextCodec.codecForLocale()
        self._decoder_stdout = codec.makeDecoder()
        # only necessary when stderr channel isn't merged into stdout:
        self._decoder_stderr = codec.makeDecoder()

        self.readyReadStandardOutput.connect(self._ready_read_standard_output)
        # only necessary when stderr channel isn't merged into stdout:
        self.readyReadStandardError.connect(self._ready_read_standard_error)

    @pyqtSlot()
    def _ready_read_standard_output(self):
        raw_bytes = self.readAllStandardOutput()
        text = self._decoder_stdout.toUnicode(raw_bytes)
        self.produce_output.emit(text)

    # only necessary when stderr channel isn't merged into stdout:
    @pyqtSlot()
    def _ready_read_standard_error(self):
        raw_bytes = self.readAllStandardError()
        text = self._decoder_stderr.toUnicode(raw_bytes)
        self.produce_error.emit(text)

if __name__ == '__main__':
    app = QApplication(sys.argv)
    ventana = windowProcess()
    ventana.show()
    sys.exit(app.exec_())

Answer 1

pyqtSlot 装饰器仅对 QObject 有意义，在我的例子中，myClassProcess 不会导致您指出的问题。

鉴于此，有 2 个解决方案：

不要在 myClassProcess 的 append_output 和 append_error 方法中使用 @pyqtSlot。

或者将 myClassProcess 设为 QObject:

class myClassProcess(<b>QObject</b>):
    def __init__(self, parent=None):
        <b>super().__init__(parent)</b>
        self.info = []

QProcess PyQt5 TypeError

QProcess PyQt5 TypeError

python

class

pyqt

qprocess

pyqt5