过去，我已经阅读了很多有关该主题的文章，并观看了Bob叔叔的有趣的演讲。但是，我始终很难正确地构建桌面应用程序，并区分在UI端和逻辑端应该承担哪些责任。
良好做法的简短摘要就是这样的。您应该设计与UI分离的逻辑，以便无论哪种后端/ UI框架，都可以（理论上）使用库。基本上，这意味着UI应该尽可能地虚设，繁重的处理应该在逻辑端进行。否则，我可以在控制台应用程序，Web应用程序或桌面应用程序上真正使用我的漂亮库。
此外，鲍伯叔叔建议对使用哪种技术会给您带来很多好处（良好的界面）的不同讨论，这种递延概念使您可以将经过良好测试的实体高度去耦，这听起来不错，但仍然很棘手。
因此，我知道这个问题是一个相当广泛的问题，已经在整个互联网上讨论了很多次，还以大量好书进行了讨论。因此，为了从中获得好处，我将发布一个非常小的虚拟示例，尝试在pyqt上使用MCV：
import sys
import os
import random
from PyQt5 import QtWidgets
from PyQt5 import QtGui
from PyQt5 import QtCore
random.seed(1)
class Model(QtCore.QObject):
item_added = QtCore.pyqtSignal(int)
item_removed = QtCore.pyqtSignal(int)
def __init__(self):
super().__init__()
self.items = {}
def add_item(self):
guid = random.randint(0, 10000)
new_item = {
"pos": [random.randint(50, 100), random.randint(50, 100)]
}
self.items[guid] = new_item
self.item_added.emit(guid)
def remove_item(self):
list_keys = list(self.items.keys())
if len(list_keys) == 0:
self.item_removed.emit(-1)
return
guid = random.choice(list_keys)
self.item_removed.emit(guid)
del self.items[guid]
class View1():
def __init__(self, main_window):
self.main_window = main_window
view = QtWidgets.QGraphicsView()
self.scene = QtWidgets.QGraphicsScene(None)
self.scene.addText("Hello, world!")
view.setScene(self.scene)
view.setStyleSheet("background-color: red;")
main_window.setCentralWidget(view)
class View2():
add_item = QtCore.pyqtSignal(int)
remove_item = QtCore.pyqtSignal(int)
def __init__(self, main_window):
self.main_window = main_window
button_add = QtWidgets.QPushButton("Add")
button_remove = QtWidgets.QPushButton("Remove")
vbl = QtWidgets.QVBoxLayout()
vbl.addWidget(button_add)
vbl.addWidget(button_remove)
view = QtWidgets.QWidget()
view.setLayout(vbl)
view_dock = QtWidgets.QDockWidget('View2', main_window)
view_dock.setWidget(view)
main_window.addDockWidget(QtCore.Qt.RightDockWidgetArea, view_dock)
model = main_window.model
button_add.clicked.connect(model.add_item)
button_remove.clicked.connect(model.remove_item)
class Controller():
def __init__(self, main_window):
self.main_window = main_window
def on_item_added(self, guid):
view1 = self.main_window.view1
model = self.main_window.model
print("item guid={0} added".format(guid))
item = model.items[guid]
x, y = item["pos"]
graphics_item = QtWidgets.QGraphicsEllipseItem(x, y, 60, 40)
item["graphics_item"] = graphics_item
view1.scene.addItem(graphics_item)
def on_item_removed(self, guid):
if guid < 0:
print("global cache of items is empty")
else:
view1 = self.main_window.view1
model = self.main_window.model
item = model.items[guid]
x, y = item["pos"]
graphics_item = item["graphics_item"]
view1.scene.removeItem(graphics_item)
print("item guid={0} removed".format(guid))
class MainWindow(QtWidgets.QMainWindow):
def __init__(self):
super().__init__()
# (M)odel ===> Model/Library containing should be UI agnostic, right now it's not
self.model = Model()
# (V)iew ===> Coupled to UI
self.view1 = View1(self)
self.view2 = View2(self)
# (C)ontroller ==> Coupled to UI
self.controller = Controller(self)
self.attach_views_to_model()
def attach_views_to_model(self):
self.model.item_added.connect(self.controller.on_item_added)
self.model.item_removed.connect(self.controller.on_item_removed)
if __name__ == "__main__":
app = QtWidgets.QApplication(sys.argv)
form = MainWindow()
form.setMinimumSize(800, 600)
form.show()
sys.exit(app.exec_())
上面的代码段包含许多缺陷，最明显的是该模型与UI框架耦合（QObject，pyqt信号）。我知道该示例确实是虚拟的，您可以使用单个QMainWindow在几行代码上进行编码，但我的目的是了解如何正确构建更大的pyqt应用程序。
题
您将如何遵循良好的常规做法，使用MVC适当地设计大型PyQt应用程序？
参考资料
我在这里提出了类似的问题