在for循环PyQT5的过程中更新QT元素 -|目标|--|预期/实际|-

如何解决在for循环PyQT5的过程中更新QT元素 -|目标|--|预期/实际|-

-|摘要|-

您好，最近我一直在努力创建排序算法的图形表示。但是目前，我一直试图找到一种方法来与所有for循环完全完成后立即排序的元素进行比较，以更新gui元素。为了解决这个问题，我尝试使用pythons线程库在自己的线程中运行method（loop），该方法应该能够在多个帧而不是一个帧的过程中运行，但是这会导致相同的结果，有时甚至是所有gui元素将消失（仍将存在，只是在屏幕上不可见）

-|目标|-

具有在x时间内观察gui元素的功能，可以显示排序算法的进度

-|预期/实际|-

Actual：在更新所有gui元素之前，for循环要等到完成 预期：超时更新gui元素（x秒）

-| MRE（最小可复制示例）|-

第45行左右是我运行算法的地方，第40行正上方显示了我尝试进行线程化的方法

from PyQt5 import QtWidgets,QtCore,QtGui
from PyQt5.QtWidgets import QApplication,QWidget,QGridLayout
import sys
import random

class MRE(QWidget):

    def __init__(self):
        super().__init__()
        #initialized Values
        self.n = 250 # n is the Number Of Values In the array to be sorted
        self.values = [] #Holds all the Rectangle Objects that are in the Graphics Scene

        # Set Layout
        grid = QGridLayout()
        self.setLayout(grid)

        # Set Size of Window
        self.resize(600,400)

        # Set Widgets
        self.sortingGraphic = QtWidgets.QGraphicsView(self)
        self.sortingGraphic.resize(600,400)

        # Setup Scene View
        self.scene = QtWidgets.QGraphicsScene()
        self.sortingGraphic.setScene(self.scene)

        # Open Application
        self.show()

    def main(self):
        self.scene.setSceneRect(0,self.sortingGraphic.width() - 5,self.sortingGraphic.height() - 5)
        self.value_gen() #Generates Random Values to Array Change n (in __init__) to change amount


        #---- Help! ----
        # Also Tried the Following
        #import threading
        #threading.Thread(self.bubbleSort()).start()

        # Runs Bubble Sort Algorithm that will sort the Values in order
        self.bubbleSort()

    def bubbleSort(self):
        n = len(self.values)

        for i in range(n - 1):
            for j in range(0,n - i - 1):
                if self.values[j].scenePos().y() > self.values[j + 1].scenePos().y():
                    # Update Graphic Positions
                    self.switch(self.values[j],self.values[j + 1])

                    # Update Position in List
                    self.values[j],self.values[j + 1] = self.values[j + 1],self.values[j]

    def switch(self,a: QtWidgets.QGraphicsRectItem,b: QtWidgets.QGraphicsRectItem):
        #Holds temporary values of each item
        temp_a = a.scenePos()
        temp_b = b.scenePos()

        # Updates Graphics View and swaps positions
        a.setPos(temp_b.x(),temp_a.y())
        b.setPos(temp_a.x(),temp_b.y())

    def value_gen(self):
        # Grab the Size of the View and calculate width of each line
        width = (self.sortingGraphic.geometry().width() - 5) / self.n

        for value in range(self.n):
            # Randomizes Height Between 0 and Height of Screen
            height = random.randrange(0,self.sortingGraphic.geometry().height() - 5)

            # Create Rect Item
            rect_item = QtWidgets.QGraphicsRectItem(QtCore.QRectF(0,width,height))
            rect_item.setPos(width * value,self.sortingGraphic.height() - height)

            # Adds Item to Values List
            self.values.append(rect_item)

            # Adds Rect item to Screen
            self.scene.addItem(rect_item)


if __name__ == '__main__':
    app = QApplication(sys.argv)
    mre = MRE()
    mre.main()
    sys.exit(app.exec_())

最终思想

如果有人对我可以尝试的方法有任何想法，将不胜感激，谢谢！！

解决方法

可视化算法的目的不是可视化算法的速度，而是可视化数据的行为，因此，在这种情况下，在t秒内执行每次通过的计时器就足够了，如下所示：

import random
import sys

from PyQt5 import QtWidgets,QtCore,QtGui


def bubbleSort(elements,switch,compare):
    n = len(elements)
    for i in range(n - 1):
        for j in range(0,n - i - 1):
            if compare(elements[j],elements[j + 1]):
                switch(elements[j],elements[j + 1])
                elements[j],elements[j + 1] = (
                    elements[j + 1],elements[j],)
                yield


class MRE(QtWidgets.QWidget):
    def __init__(self):
        super().__init__()
        self.n = 100
        self.items = []
        self.resize(600,400)
        self.view = QtWidgets.QGraphicsView()
        self.view.setRenderHints(QtGui.QPainter.Antialiasing)
        self.view.scale(1,-1)
        self.scene = QtWidgets.QGraphicsScene()
        self.view.setScene(self.scene)
        grid = QtWidgets.QGridLayout(self)
        grid.addWidget(self.view)

        self.timer = QtCore.QTimer(interval=10,timeout=self.next_step)

    def main(self):
        self.value_gen()
        self.start_algorithm()
        self.show()

    def value_gen(self):
        height = 100
        width = 2

        for value in range(self.n):
            h = random.randrange(0,height)
            item = self.scene.addRect(QtCore.QRectF(0,width,h))
            item.setPos(2 * value * width,0)
            item.setPen(QtGui.QPen(QtCore.Qt.NoPen))
            item.setBrush(QtGui.QColor("black"))
            self.items.append(item)

        self.fix_size()

    def start_algorithm(self):
        self.algorithm = bubbleSort(self.items,self.switch,self.compare)
        self.timer.start()

    def next_step(self):
        try:
            next(self.algorithm)
        except StopIteration:
            self.timer.stop()

    def switch(self,item_a,item_b):
        pos_a = item_a.scenePos()
        pos_b = item_b.scenePos()
        item_a.setPos(pos_b)
        item_b.setPos(pos_a)
        self.fix_size()

    def compare(self,item_b):
        return item_a.rect().height() < item_b.rect().height()

    def fix_size(self):
        self.view.fitInView(self.scene.itemsBoundingRect())

    def resizeEvent(self,event):
        self.fix_size()
        super().resizeEvent(event)


if __name__ == "__main__":
    app = QtWidgets.QApplication(sys.argv)
    mre = MRE()
    mre.main()
    sys.exit(app.exec_())