#!/usr/bin/env python
# -*- coding: utf-8 -*-
from PyQt5.QtCore import QPropertyAnimation
from PyQt5.QtWidgets import QWidget, QVBoxLayout, QPushButton


# Created on 2018年6月14日
# author: Irony
# site: https://pyqt5.com, https://github.com/892768447
# email: 892768447@qq.com
# file: 动画特效.淡入淡出
# description:
__Author__ = """By: Irony
QQ: 892768447
Email: 892768447@qq.com"""
__Copyright__ = 'Copyright (c) 2018 Irony'
__Version__ = 1.0


class Window(QWidget):

    def __init__(self, *args, **kwargs):
        super(Window, self).__init__(*args, **kwargs)
        self.resize(400, 400)
        layout = QVBoxLayout(self)
        layout.addWidget(QPushButton('退出', self, clicked=self.doClose))

        # 窗口透明度动画类
        self.animation = QPropertyAnimation(self, b'windowOpacity')
        self.animation.setDuration(1000)  # 持续时间1秒

        # 执行淡入
        self.doShow()

    def doShow(self):
        try:
            # 尝试先取消动画完成后关闭窗口的信号
            self.animation.finished.disconnect(self.close)
        except:
            pass
        self.animation.stop()
        # 透明度范围从0逐渐增加到1
        self.animation.setStartValue(0)
        self.animation.setEndValue(1)
        self.animation.start()

    def doClose(self):
        self.animation.stop()
        self.animation.finished.connect(self.close)  # 动画完成则关闭窗口
        # 透明度范围从1逐渐减少到0
        self.animation.setStartValue(1)
        self.animation.setEndValue(0)
        self.animation.start()


if __name__ == '__main__':
    import sys
    from PyQt5.QtWidgets import QApplication
    app = QApplication(sys.argv)
    w = Window()
    w.show()
    sys.exit(app.exec_())