模擬透明背景

Question

由於所有窗口管理器都不支持此功能，因此我曾想過在顯示背景之前複製背景。
但是這帶來了幾個問題。
- 背景並不總是正確備份。我不知道爲什麼。
- 使用此方法不可能用鼠標移動窗口。因爲用hide（）和show（）焦點會丟失。

您是否認爲這些問題有解決方案？

#!/bin/env python3 

from PyQt5.QtCore import Qt 
from PyQt5.QtGui import QColor, QPainter, QPen 
from PyQt5.QtWidgets import QApplication, QMainWindow 

class Window(QMainWindow): 

    def __init__(self): 
     super().__init__() 
     self.setWindowFlags(Qt.FramelessWindowHint) 
     self.offset= None 
     self.ps= app.primaryScreen() 
     self.setGeometry(500, 500, 200, 200) 
     self.saveBackground() 

    def keyPressEvent(self, event): 
     if event.key() == Qt.Key_Escape: 
      self.close() 
     elif event.key() in [ Qt.Key_Left, Qt.Key_Right, Qt.Key_Up, Qt.Key_Down ]: 
      point= self.geometry().topLeft() 
      if event.key() == Qt.Key_Left: 
       point.setX(point.x() - 1) 
      elif event.key() == Qt.Key_Right: 
       point.setX(point.x() + 1) 
      elif event.key() == Qt.Key_Up: 
       point.setY(point.y() - 1) 
      elif event.key() == Qt.Key_Down: 
       point.setY(point.y() + 1) 
      self.move(point) 
      self.saveBackground() 

    def mousePressEvent(self, event): 
     self.offset= event.pos() 

    def mouseMoveEvent(self, event): 
     self.move(self.mapToParent(event.pos() - self.offset)) 
     self.saveBackground() 

    def paintEvent(self, event): 
     qp= QPainter() 
     qp.begin(self) 
     qp.drawPixmap(0, 0, self.pix) 
     qp.setPen(QPen(QColor(255, 0, 0), 2, Qt.SolidLine)) 
     qp.drawRect(1, 1, self.width() - 2, self.height() - 2) 

    def saveBackground(self): 
     geo= self.frameGeometry() 
     self.hide() 
     self.pix= self.ps.grabWindow(app.desktop().winId(), geo.x(), geo.y(), geo.width(), geo.height()) 
     self.show() 

if __name__ == "__main__": 
    app= QApplication([]) 
    ui= Window() 
    ui.show() 
    exit(app.exec_()) 

Answer 1

#!/bin/env python3 

from PyQt5.QtCore import Qt 
from PyQt5.QtGui import QColor, QPainter, QPen 
from PyQt5.QtWidgets import QApplication, QMainWindow 
from time import time 

class Window(QMainWindow): 

    def __init__(self): 
     super().__init__() 
     self.setWindowFlags(Qt.FramelessWindowHint) 
     self.offset= None 
     self.ps= app.primaryScreen() 
     self.setGeometry(500, 500, 200, 200) 
     self.saveBackground() 
     self.csec= time() 
     self.moving= False 
     self.ratio= 2 

    def keyPressEvent(self, event): 
     if event.key() == Qt.Key_Escape: 
      self.close() 
     elif event.key() in [ Qt.Key_Left, Qt.Key_Right, Qt.Key_Up, Qt.Key_Down ]: 
      if time() > self.csec + 1.2: 
       point= self.geometry().topLeft() 
       if event.key() == Qt.Key_Left: 
        point.setX(point.x() - 1) 
       elif event.key() == Qt.Key_Right: 
        point.setX(point.x() + 1) 
       elif event.key() == Qt.Key_Up: 
        point.setY(point.y() - 1) 
       elif event.key() == Qt.Key_Down: 
        point.setY(point.y() + 1) 
       self.move(point) 
       self.csec= time() 
       self.saveBackground() 
     super().keyPressEvent(event) 

    def mousePressEvent(self, event): 
     self.offset= event.pos() 
     self.moving= True 
     self.repaint() 

    def mouseReleaseEvent(self, event): 
     self.saveBackground() 
     self.moving= False 
     self.repaint() 

    def mouseMoveEvent(self, event): 
     self.move(self.mapToParent(event.pos() - self.offset)) 

    def paintEvent(self, event): 
     qp= QPainter() 
     qp.begin(self) 
     if self.moving: 
      qp.setBrush(QColor(220, 220, 220)) 
      qp.drawRect(0, 0, self.width() - 1, self.height() - 1) 
     else: 
      qp.drawPixmap(0, 0, self.pix.scaled(self.size() * self.ratio, Qt.KeepAspectRatio)) 
     qp.setPen(QPen(QColor(255, 0, 0), 1, Qt.SolidLine)) 
     qp.drawRect(0, 0, self.width() - 1, self.height() - 1) 

    def saveBackground(self): 
     self.hide() 
     self.pix= self.ps.grabWindow(app.desktop().winId(), self.x(), self.y(), self.width(), self.height()) 
     self.show() 

if __name__ == "__main__": 
    app= QApplication([]) 
    ui= Window() 
    ui.show() 
    exit(app.exec_())