在线程中操作UI

Author: 892768447

QMetaObject/CallInThread.py

@@ -0,0 +1,114 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+"""
+Created on 2023/02/23
+@author: Irony
+@site: https://pyqt.site https://github.com/PyQt5
+@email: 892768447@qq.com
+@file: CallInThread.py
+@description:
+"""
+import time
+from datetime import datetime
+from threading import Thread
+
+from PyQt5.QtCore import (Q_ARG, Q_RETURN_ARG, QMetaObject, Qt, QThread,
+                          pyqtSignal, pyqtSlot)
+from PyQt5.QtWidgets import QApplication, QHBoxLayout, QTextBrowser, QWidget
+
+
+class ThreadQt(QThread):
+
+    def __init__(self, textBrowser, *args, **kwargs):
+        super(ThreadQt, self).__init__(*args, **kwargs)
+        self._textBrowser = textBrowser
+
+    def stop(self):
+        self.requestInterruption()
+
+    def run(self):
+        while not self.isInterruptionRequested():
+            text = datetime.now().strftime('%Y-%m-%d %H:%M:%S')
+            # 通过`invokeMethod`直接调用对应的槽函数
+            # 1. 获取函数`isReadOnly1`返回值, self.parent() 是Window窗口对象
+            # NOTE：注意这里获取返回值要用 `Qt.DirectConnection` 方式
+            retValue = QMetaObject.invokeMethod(self.parent(), 'isReadOnly1',
+                                                Qt.DirectConnection,
+                                                Q_RETURN_ARG(bool))
+            # 2. 通过`invokeMethod`队列调用对应控件槽函数`append`
+            argValue = Q_ARG(str, text + ' readOnly: ' + str(retValue))
+            QMetaObject.invokeMethod(self._textBrowser, 'append',
+                                     Qt.QueuedConnection, argValue)
+            self.sleep(1)
+
+
+class ThreadPy(Thread):
+
+    def __init__(self, textBrowser, parent, *args, **kwargs):
+        super(ThreadPy, self).__init__(*args, **kwargs)
+        self._running = True
+        self._textBrowser = textBrowser
+        self._parent = parent
+
+    def stop(self):
+        self._running = False
+
+    def run(self):
+        while self._running:
+            text = datetime.now().strftime('%Y-%m-%d %H:%M:%S')
+            # 通过`invokeMethod`队列调用对应控件信号，`self._parent`是Window窗口对象
+            QMetaObject.invokeMethod(self._parent, 'appendText',
+                                     Qt.QueuedConnection,
+                                     Q_ARG(str, text + ' from Signal'))
+            # 通过`invokeMethod`队列调用对应控件槽函数`append`
+            QMetaObject.invokeMethod(self._textBrowser, 'append',
+                                     Qt.QueuedConnection,
+                                     Q_ARG(str, text + ' to Slot'))
+            time.sleep(1)
+
+
+class Window(QWidget):
+
+    # 更新信号
+    appendText = pyqtSignal(str)
+
+    def __init__(self, *args, **kwargs):
+        super(Window, self).__init__(*args, **kwargs)
+        layout = QHBoxLayout(self)
+        self.textBrowser1 = QTextBrowser(self)
+        self.textBrowser2 = QTextBrowser(self)
+        layout.addWidget(self.textBrowser1)
+        layout.addWidget(self.textBrowser2)
+
+        self.appendText.connect(self.textBrowser2.append)
+
+        # Qt线程
+        self.thread1 = ThreadQt(self.textBrowser1, self)
+        self.thread1.start()
+
+        # PY线程
+        self.thread2 = ThreadPy(self.textBrowser2, self)
+        self.thread2.start()
+
+    @pyqtSlot(result=bool)
+    def isReadOnly1(self):
+        # 线程中直接调用该槽函数获取UI中的内容
+        return self.textBrowser1.isReadOnly()
+
+    def closeEvent(self, event):
+        self.thread1.stop()
+        self.thread2.stop()
+        self.thread1.wait()
+        self.thread2.join()
+        super(Window, self).closeEvent(event)
+
+
+if __name__ == '__main__':
+    import cgitb
+    import sys
+
+    cgitb.enable(format='text')
+    app = QApplication(sys.argv)
+    w = Window()
+    w.show()
+    sys.exit(app.exec_())

QMetaObject/README.en.md

@@ -0,0 +1,24 @@
+# QMetaObject
+
+- 目录
+  - [在线程中操作UI](#1在线程中操作UI)
+
+## 1、在线程中操作UI
+[运行 CallInThread.py](CallInThread.py)
+
+如果想在`QThread`或者`threading.Thread`中不通过信号直接操作UI，则可以使用`QMetaObject.invokeMethod`调用。
+
+该函数一般有常用的几种调用方法：
+
+1. 直接调用槽函数：`QMetaObject.invokeMethod(uiobj, 'slot_method', Qt.QueuedConnection)`
+2. 直接调用信号：`QMetaObject.invokeMethod(uiobj, 'signal_method', Qt.QueuedConnection)`
+3. 调用信号或槽函数并传递参数：`QMetaObject.invokeMethod(uiobj, 'method', Qt.QueuedConnection, Q_ARG(str, 'text'))`
+4. 调用槽函数得到返回值：`QMetaObject.invokeMethod(uiobj, 'slot_method', Qt.DirectConnection)`
+5. 调用带参数的槽函数得到返回值：`QMetaObject.invokeMethod(uiobj, 'slot_method', Qt.DirectConnection, Q_ARG(bool, False))`
+
+这里需要注意：
+
+1. 调用函数都是异步队列方式，需要使用`Qt.QueuedConnection`
+2. 而要得到返回值则必须使用同步方式, 即`Qt.DirectConnection`
+
+![CallInThread](ScreenShot/CallInThread.png)

QMetaObject/README.md

@@ -259,6 +259,8 @@
     - [最小化到系统托盘](QSystemTrayIcon/MinimizeToTray.py)
   - [QSystemTrayIcon](QSystemTrayIcon)
     - [系统托盘闪烁](QSystemTrayIcon/TrayNotify.py)
+  - [QMetaObject](QMetaObject)
+    - [在线程中操作UI](QMetaObject/CallInThread.py)
 
 - [Demo](Demo)
   - [重启窗口Widget](Demo/RestartWindow.py)