SetText in Pyqt5

Question

我正在用pyqt5开发一个应用程序，我遇到了一个问题。有一个接收数据的脚本，在pyqt5中，"main_text.setText (str (TEXT))“行输出数据，格式为"str”​，但是脚本本身每0.2s接收和输出数据，但是在"main_text.setText (str (文本))“行中，它们不会被更新。尝试通过时间睡眠功能，这个应用程序不能工作，

pyqt5中有什么方法可以将不同的数据输出到相同的文本中？

我的代码：

from PyQt5 import QtWidgets
from PyQt5.QtWidgets import QApplication, QMainWindow

import sys
import MetaTrader5 as mt5

import time

mt5.initialize()

ticket_info = mt5.symbol_info_tick("EURUSD")._asdict()
bid_usd = mt5.symbol_info_tick("EURUSD").bid

def applecation():
    app = QApplication(sys.argv)
    window = QMainWindow()

    window.setWindowTitle('Test Programm')
    window.setGeometry(300, 250, 350, 200)


    main_text = QtWidgets.QLabel(window)
    main_text.setText(str(bid_usd))
    main_text.move(100,100)
    main_text.adjustSize()

    window.show()

    sys.exit(app.exec_())

if __name__ == "__main__":
    applecation()

Answer 1

您只调用了一次symbol_info_tick方法，因此您将只获得一个数据，如果您希望每T秒获得该信息，那么您必须使用一个在二级线程中执行的while True，这样它就不会阻塞GUI并通过信号发送信息。

import sys
import threading
import time

from PyQt5.QtCore import QObject, pyqtSignal
from PyQt5.QtWidgets import QApplication, QLabel, QMainWindow

import MetaTrader5 as mt5


class MetaTrader5Worker(QObject):
    dataChanged = pyqtSignal(str)

    def start(self):
        threading.Thread(target=self._execute, daemon=True).start()

    def _execute(self):
        mt5.initialize()
        while True:
            bid_usd = mt5.symbol_info_tick("EURUSD").bid
            self.dataChanged.emit(str(bid_usd))
            time.sleep(0.5)


class MainWindow(QMainWindow):
    def __init__(self, parent=None):
        super().__init__(parent)
        self.label = QLabel(self)
        self.setWindowTitle("Test Programm")
        self.setGeometry(300, 250, 350, 200)

    def handle_data_changed(self, text):
        self.label.setText(text)
        self.label.adjustSize()


def main():
    app = QApplication(sys.argv)

    window = MainWindow()
    window.show()

    worker = MetaTrader5Worker()
    worker.dataChanged.connect(window.handle_data_changed)
    worker.start()

    sys.exit(app.exec_())


if __name__ == "__main__":
    main()

Answer 2

您可以使用线程，它比QThreads更容易理解

from PyQt5 import QtWidgets
from PyQt5.QtWidgets import QApplication, QMainWindow
import threading
import sys
import MetaTrader5 as mt5

import time

mt5.initialize()

ticket_info = mt5.symbol_info_tick("EURUSD")._asdict()
bid_usd = mt5.symbol_info_tick("EURUSD").bid

def applecation():
    app = QApplication(sys.argv)
    window = QMainWindow()

    window.setWindowTitle('Test Programm')
    window.setGeometry(300, 250, 350, 200)


    main_text = QtWidgets.QLabel(window)
    main_text.move(100,100)
    main_text.adjustSize()

    def update_text():
        while True:
            main_text.setText(str(bid_usd))
            time.sleep(0.2)

    t1 = threading.Thread(target = update_text())
    t1.start()


    window.show()

    sys.exit(app.exec_())

if __name__ == "__main__":
    applecation()