函数	描述
setMask(self, QBitmap) setMask(self, QRegion)	setMask()的作用是为调用它的控件增加一个遮罩，遮住所选区域以外的部分，使之看起来是透明的。它的参数可以为QBitmap或QRegion对象。
paintEvent(self, QPaintEvent)	通过重载paintEvent()函数绘制窗口背景

QPixmap和QBitmap绘图的效果对比

import sys
from PyQt5.QtWidgets import QApplication, QWidget
from PyQt5.QtGui import QPixmap, QPainter, QBitmap

class MyForm(QWidget):
    def __init__(self, parent=None):
        super(MyForm, self).__init__(parent)
        self.setWindowTitle("不规则窗口的实现例子")

    def paintEvent(self, event):
        painter = QPainter(self)
        painter.drawPixmap(0, 0, 280, 390, QPixmap(r"./pyqt5/images/dog.jpg"))
        painter.drawPixmap(300, 0, 280, 390, QBitmap(r"./pyqt5/images/dog.jpg"))

if __name__ == "__main__":
    app = QApplication(sys.argv)
    form = MyForm()
    form.show()
    sys.exit(app.exec_())

不可以拖动的不规则窗口

import sys
from PyQt5.QtWidgets import QApplication, QWidget
from PyQt5.QtGui import QPixmap, QPainter, QBitmap

class WinForm(QWidget):
    def __init__(self, parent=None):
        super(WinForm, self).__init__(parent)
        self.setWindowTitle("不规则窗口的实现例子")

        self.pix = QBitmap("./pyqt5/images/mask.png")
        self.resize(self.pix.size())
        self.setMask(self.pix)

    def paintEvent(self, event):
        painter = QPainter(self)
        # 在指定区域直接绘制窗口背景
        painter.drawPixmap(0, 0, self.pix.width(), self.pix.height(), QPixmap("./pyqt5/images/screen1.jpg"))

if __name__ == "__main__":
    app = QApplication(sys.argv)
    win = WinForm()
    win.show()
    sys.exit(app.exec_())

可以拖动的不规则窗口

import sys
from PyQt5.QtWidgets import QApplication  ,QWidget 
from PyQt5.QtGui import  QPixmap,   QPainter  ,  QCursor , QBitmap
from PyQt5.QtCore import Qt 

class ShapeWidget(QWidget):  
	def __init__(self,parent=None):  
		super(ShapeWidget,self).__init__(parent)
		self.setWindowTitle("不规则的，可以拖动的窗体实现例子") 
		self.mypix()	

    # 显示不规则 pic
	def mypix(self):
		self.pix = QBitmap( "./pyqt5/images/mask.png" )
		self.resize(self.pix.size())       
		self.setMask(self.pix)
		print( self.pix.size())
		self.dragPosition = None

	# 重定义鼠标按下响应函数mousePressEvent(QMouseEvent)和鼠标移动响应函数mouseMoveEvent(QMouseEvent)，使不规则窗体能响应鼠标事件，随意拖动。
	def mousePressEvent(self, event):
		if event.button() == Qt.LeftButton:
			self.m_drag=True
			self.m_DragPosition=event.globalPos()-self.pos()
			event.accept()
			self.setCursor(QCursor(Qt.OpenHandCursor))
		if event.button()==Qt.RightButton:  
			self.close()  
			
	def mouseMoveEvent(self, QMouseEvent):
		if Qt.LeftButton and self.m_drag:
		    # 当左键移动窗体修改偏移值
			self.move(QMouseEvent.globalPos()- self.m_DragPosition )
			QMouseEvent.accept()
	
	def mouseReleaseEvent(self, QMouseEvent):
		self.m_drag=False
		self.setCursor(QCursor(Qt.ArrowCursor))
    
    #一般 paintEvent 在窗体首次绘制加载， 要重新加载paintEvent 需要重新加载窗口使用 self.update() or  self.repaint()    
	def paintEvent(self, event):
		painter = QPainter(self)
		painter.drawPixmap(0,0,self.width(),self.height(),QPixmap("./pyqt5/images/boy.png"))
			
if __name__ == '__main__':
    app=QApplication(sys.argv)
    form=ShapeWidget()
    form.show()
    app.exec_()

不规则窗口实现动画效果

import sys
from PyQt5.QtWidgets import QApplication, QWidget
from PyQt5.QtGui import QPixmap, QPainter, QCursor
from PyQt5.QtCore import Qt, QTimer

class ShapeWidget(QWidget):
    def __init__(self, parent=None):
        super(ShapeWidget, self).__init__(parent)
        self.i = 1
        self.mypix()
        self.timer = QTimer()
        self.timer.setInterval(500) # 定时器每500毫秒更新一次
        self.timer.timeout.connect(self.timeChange)
        self.timer.start()

    # 显示不规则图片
    def mypix(self):
        self.update()
        if self.i == 5:
            self.i = 1
        self.mypic = {1:'./pyqt5/images/left.png', 2:'./pyqt5/images/up.png', 3:'./pyqt5/images/right.png', 4:'./pyqt5/images/down.png'}
        self.pix = QPixmap(self.mypic[self.i], "0", Qt.AvoidDither | Qt.ThresholdDither | Qt.ThresholdAlphaDither)
        self.resize(self.pix.size())
        self.setMask(self.pix.mask())
        self.dragPosition = None

    def mousePressEvent(self, event):
        if event.button() == Qt.LeftButton:
            self.m_drag = True
            self.m_DragPosition = event.globalPos() - self.pos()
            event.accept()
            self.setCursor(QCursor(Qt.OpenHandCursor))

    def mouseMoveEvent(self, QMouseEvent):
        if Qt.LeftButton and self.m_drag:
            self.move(QMouseEvent.globalPos() - self.m_DragPosition)
            QMouseEvent.accept()
            
    def mouseReleaseEvent(self, QMouseEvent):
        self.m_drag = False
        self.setCursor(QCursor(Qt.ArrowCursor))

    def paintEvent(self, event):
        painter = QPainter(self)
        painter.drawPixmap(0, 0, self.pix.width(), self.pix.height(), self.pix)

    def mouseDoubleClickEvent(self, event):
        if event.button() == 1:
            self.i += 1
            self.mypix()

    def timeChange(self):
        self.i += 1
        self.mypix()

if __name__ == "__main__":
    app = QApplication(sys.argv)
    win = ShapeWidget()
    win.show()
    sys.exit(app.exec_())

加载GIF动画效果

import sys
from PyQt5.QtWidgets import QApplication, QLabel, QWidget
from PyQt5.QtCore import Qt
from PyQt5.QtGui import QMovie

class LoadingGifWin(QWidget):
    def __init__(self, parent=None):
        super(LoadingGifWin, self).__init__(parent)
        self.label = QLabel('', self)
        self.setFixedSize(128, 128)        
        self.setWindowFlags(Qt.Dialog | Qt.CustomizeWindowHint)
        self.movie = QMovie("./pyqt5/images/loading.gif")
        self.label.setMovie(self.movie)
        self.movie.start()
        
if __name__ == "__main__":
    app = QApplication(sys.argv)
    win = LoadingGifWin()
    win.show()
    sys.exit(app.exec_())