Pyside6动画矩形故障

Question

我正在尝试制作渐隐循环的矩形区域。我使用了here中的基本代码，决定对其进行扩展。它只是闪烁的矩形，但我需要平滑的淡入和淡出效果。所以我决定创建一个方法来计算新的不透明度百分比，并将其设置为painter。但它不是循环工作的。

现在这是我的课了

class HighlightRect(QFrame):
board_width = 400  # width of frame
board_height = 400  #height of frame

def __init__(self, parent, x, y, width=50, height=50, blink_speed=1000):
    super().__init__(parent)
    self.blink_speed = blink_speed
    self.opacity_timer = self.blink_speed
    self.board_height = self.parent().height()
    self.board_width = self.parent().width()
    self.square_height = height
    self.square_width = width
    self.highlight_x = x
    self.highlight_y = y


    #self.setFocusPolicy(QtCore.Qt.StrongFocus)
    self.timer_draw = QtCore.QTimer(self)
    self.timer_draw.timeout.connect(self.draw)
    self.timer_draw.start(self.blink_speed)

    self.color = QtCore.Qt.red
    self.is_draw = False
    self.x_apple = 0
    self.y_apple = 0
    self.draw()

def blink(self, painter):
    self.color = QtCore.Qt.red
    while self.opacity_timer >= 0:
        self.opacity_timer -= 1 / 10  # просто подбор
        percents = round(int(self.opacity_timer / self.blink_speed * 100)/100, 1)
        print(percents)
        painter.setOpacity(percents)



def paintEvent(self, event):
    painter = QtGui.QPainter(self)

    print ("Paint Event?")
    if self.is_draw == True:
        print ("Draw")
        #self.color = QtCore.Qt.red
        self.blink_thread = threading.Thread(name='background', target=lambda: self.blink(painter))
        self.blink_thread.start()
    else:

        self.opacity_timer = self.blink_speed
        print ("Do not draw")
        self.color = QtCore.Qt.transparent
        threading.SystemExit = SystemExit
    painter.setPen(self.color)
    painter.drawRect(self.rect)

def draw(self):
    self.is_draw = not self.is_draw
    self.rect = QRect(self.highlight_x, self.highlight_y, self.square_width, self.square_height)
    self.update()

在blink函数内部改变不透明度，但在while循环外部工作，但它是静态的。没有变化。改变循环中的不透明度是不起作用的。怎么了？也许这里有另一种更正确的方法来得到我想要的东西？

Answer 1

一种可能的解决方案是创建一个处理不透明度的QProperty，然后使用QPropertyAnimation使更改平滑。

import random
import sys

from PySide6.QtCore import Property, Signal, QPropertyAnimation, QRect, Qt
from PySide6.QtGui import QPainter
from PySide6.QtWidgets import QFrame, QApplication


class Board(QFrame):
    rect_opacity_changed = Signal(name="rectOpacityChanged")

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

        self._rect_opacity = 1.0
        self._rect = QRect(0, 0, 50, 50)

        self._opacity_animation = QPropertyAnimation(
            targetObject=self, propertyName=b"rect_opacity", duration=3000
        )
        for p, v in ((0.0, 0.0), (0.3, 1.0), (0.7, 1.0), (1.0, 0.0)):
            self._opacity_animation.setKeyValueAt(p, v)

        self._opacity_animation.finished.connect(self.change)

        self.change()

    @Property(float, notify=rect_opacity_changed)
    def rect_opacity(self):
        return self._rect_opacity

    @rect_opacity.setter
    def rect_opacity(self, opacity):
        self._rect_opacity = opacity
        self.rect_opacity_changed.emit()
        self.update()

    def change(self):
        x = random.randint(0, self.width() - self._rect.width())
        y = random.randint(0, self.height() - self._rect.height())
        self._rect.moveTo(x, y)
        self._opacity_animation.start()

    def paintEvent(self, event):
        painter = QPainter(self)
        painter.setOpacity(self.rect_opacity)
        painter.setPen(Qt.red)
        painter.drawRect(self._rect)


def main():

    app = QApplication([])
    board = Board()
    board.show()
    sys.exit(app.exec())


if __name__ == "__main__":
    main()