如何在 Qt5 中 parent 调整大小后调整方形 children 小部件的大小？
How to resize square children widgets after parent resize in Qt5?
我想用方形小部件做板。当我 运行 编写代码时，它创建了漂亮的板，但在调整大小后它变得很难看。我正在尝试使用 resize Event 调整它的大小，但它存在（可能存在一些错误）。我不知道如何在调整 parent.
后调整 children 的大小
Children 小部件必须是正方形所以这也是一个问题，因为我不能使用自动扩展。也许这是简单的问题，但我找不到解决方案。我花了几个小时测试不同的想法，但它现在可以正常工作了。
这是我想要调整大小的（点击最大化）：
最大化后它看起来很难看（我应该更改 children 小部件但是在什么事件上（我认为在 resizeEvent 上但它不起作用）以及如何（从 parent 或 [=56= 设置] 导致程序退出）。
这是我的最小化代码：
import logging
import sys
from PyQt5 import QtCore, QtGui
from PyQt5.QtCore import QSize
from PyQt5.QtGui import QFont, QPaintEvent, QPainter
from PyQt5.QtWidgets import QApplication, QWidget, QGridLayout
class Application(QApplication):
pass
class Board(QWidget):
def square_size(self):
size = self.size()
min_size = min(size.height(), size.width())
min_size_1_8 = min_size // 8
square_size = QSize(min_size_1_8, min_size_1_8)
logging.debug(square_size)
return square_size
def __init__(self, parent=None):
super().__init__(parent=parent)
square_size = self.square_size()
grid = QGridLayout()
grid.setSpacing(0)
squares = []
for x in range(8):
for y in range(8):
square = Square(self, (x + y - 1) % 2)
squares.append(squares)
square.setFixedSize(square_size)
grid.addWidget(square, x, y)
self.squares = squares
self.setLayout(grid)
def resizeEvent(self, event: QtGui.QResizeEvent) -> None:
# how to resize children?
logging.debug('Resize %s.', self.__class__.__name__)
logging.debug('Size %s.', event.size())
super().resizeEvent(event)
class Square(QWidget):
def __init__(self, parent, color):
super().__init__(parent=parent)
if color:
self.color = QtCore.Qt.white
else:
self.color = QtCore.Qt.black
def resizeEvent(self, event: QtGui.QResizeEvent) -> None:
logging.debug('Resize %s.', self.__class__.__name__)
logging.debug('Size %s.', event.size())
super().resizeEvent(event)
def paintEvent(self, event: QPaintEvent) -> None:
painter = QPainter()
painter.begin(self)
painter.fillRect(self.rect(), self.color)
painter.end()
def main():
logging.basicConfig(level=logging.DEBUG)
app = Application(sys.argv)
app.setAttribute(QtCore.Qt.AA_EnableHighDpiScaling, True)
default_font = QFont()
default_font.setPointSize(12)
app.setFont(default_font)
board = Board()
board.setWindowTitle('Board')
# ugly look
# chessboard.showMaximized()
# looks nize but resize not works
board.show()
sys.exit(app.exec())
if __name__ == '__main__':
main()
我应该如何调整正方形 children 的大小以避免空洞？
第二次尝试 - 改进了代码，但我仍然不知道如何调整大小 children
一些居中的新想法效果更好（现在没有间隙）但我仍然不知道如何调整大小 children（不会崩溃）。
显示后():
太宽（保持比例）：
太高（保持比例）：
更大（它保持比例但 children 未缩放到自由 space - 我仍然不知道如何调整 children 大小？）：
改进代码：
import logging
import sys
from PyQt5 import QtCore, QtGui
from PyQt5.QtCore import QSize
from PyQt5.QtGui import QFont, QPaintEvent, QPainter
from PyQt5.QtWidgets import QApplication, QWidget, QGridLayout, QHBoxLayout, QVBoxLayout
class Application(QApplication):
pass
class Board(QWidget):
def square_size(self):
size = self.size()
min_size = min(size.height(), size.width())
min_size_1_8 = min_size // 8
square_size = QSize(min_size_1_8, min_size_1_8)
logging.debug(square_size)
return square_size
def __init__(self, parent=None):
super().__init__(parent=parent)
square_size = self.square_size()
vertical = QVBoxLayout()
horizontal = QHBoxLayout()
grid = QGridLayout()
grid.setSpacing(0)
squares = []
for x in range(8):
for y in range(8):
square = Square(self, (x + y - 1) % 2)
squares.append(squares)
square.setFixedSize(square_size)
grid.addWidget(square, x, y)
self.squares = squares
horizontal.addStretch()
horizontal.addLayout(grid)
horizontal.addStretch()
vertical.addStretch()
vertical.addLayout(horizontal)
vertical.addStretch()
self.setLayout(vertical)
def resizeEvent(self, event: QtGui.QResizeEvent) -> None:
# how to resize children?
logging.debug('Resize %s.', self.__class__.__name__)
logging.debug('Size %s.', event.size())
super().resizeEvent(event)
class Square(QWidget):
def __init__(self, parent, color):
super().__init__(parent=parent)
if color:
self.color = QtCore.Qt.white
else:
self.color = QtCore.Qt.black
def resizeEvent(self, event: QtGui.QResizeEvent) -> None:
logging.debug('Resize %s.', self.__class__.__name__)
logging.debug('Size %s.', event.size())
super().resizeEvent(event)
def paintEvent(self, event: QPaintEvent) -> None:
painter = QPainter()
painter.begin(self)
painter.fillRect(self.rect(), self.color)
painter.end()
def main():
logging.basicConfig(level=logging.DEBUG)
app = Application(sys.argv)
app.setAttribute(QtCore.Qt.AA_EnableHighDpiScaling, True)
default_font = QFont()
default_font.setPointSize(12)
app.setFont(default_font)
board = Board()
board.setWindowTitle('Board')
# ugly look
# chessboard.showMaximized()
# looks nice but resize not works
board.show()
sys.exit(app.exec())
if __name__ == '__main__':
main()
如何在不崩溃的情况下调整方形 children 的大小？
有两种可能的解决方案。
您可以使用 Graphics View framework，它专门用于必须考虑 custom/specific 图形和定位的此类应用程序，否则请创建布局子类。
虽然在这种情况下重新实现布局稍微简单一些，但一旦应用程序变得更加复杂，您可能会遇到一些问题。另一方面，Graphics View 框架的学习曲线陡峭，因为您需要了解它的工作原理以及对象交互的行为方式。
子类布局
假设平方数始终相同，您可以重新实现自己的布局，根据其内容设置正确的几何形状。
在这个例子中，我还创建了一个 "container" 和其他小部件来显示正在调整大小。
当window宽度很高时，会以高度为参考，水平居中：
反之，高度越大，垂直居中：
请记住，您应该不向看板添加其他小部件，否则您会遇到严重的问题。
这并非不可能，但它的实现可能要复杂得多，因为布局需要考虑其他小部件的位置、尺寸提示和可能的扩展方向，以便正确计算新的几何形状。
from PyQt5 import QtCore, QtGui, QtWidgets
class Square(QtWidgets.QWidget):
def __init__(self, parent, color):
super().__init__(parent=parent)
if color:
self.color = QtCore.Qt.white
else:
self.color = QtCore.Qt.black
self.setMinimumSize(50, 50)
def paintEvent(self, event: QtGui.QPaintEvent) -> None:
painter = QtGui.QPainter(self)
painter.fillRect(self.rect(), self.color)
class EvenLayout(QtWidgets.QGridLayout):
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.setSpacing(0)
def setGeometry(self, oldRect):
# assuming that the minimum size is 50 pixel, find the minimum possible
# "extent" based on the geometry provided
minSize = max(50 * 8, min(oldRect.width(), oldRect.height()))
# create a new squared rectangle based on that size
newRect = QtCore.QRect(0, 0, minSize, minSize)
# move it to the center of the old one
newRect.moveCenter(oldRect.center())
super().setGeometry(newRect)
class Board(QtWidgets.QWidget):
def __init__(self):
super().__init__()
self.setSizePolicy(QtWidgets.QSizePolicy.Expanding, QtWidgets.QSizePolicy.Expanding)
layout = EvenLayout(self)
self.squares = []
for row in range(8):
for column in range(8):
square = Square(self, not (row + column) & 1)
self.squares.append(square)
layout.addWidget(square, row, column)
class Chess(QtWidgets.QWidget):
def __init__(self):
super().__init__()
layout = QtWidgets.QGridLayout(self)
header = QtWidgets.QLabel('Some {}long label'.format('very ' * 20))
layout.addWidget(header, 0, 0, 1, 3, QtCore.Qt.AlignCenter)
self.board = Board()
layout.addWidget(self.board, 1, 1)
leftLayout = QtWidgets.QVBoxLayout()
layout.addLayout(leftLayout, 1, 0)
rightLayout = QtWidgets.QVBoxLayout()
layout.addLayout(rightLayout, 1, 2)
for b in range(1, 9):
leftLayout.addWidget(QtWidgets.QPushButton('Left Btn {}'.format(b)))
rightLayout.addWidget(QtWidgets.QPushButton('Right Btn {}'.format(b)))
footer = QtWidgets.QLabel('Another {}long label'.format('very ' * 18))
layout.addWidget(footer, 2, 0, 1, 3, QtCore.Qt.AlignCenter)
if __name__ == '__main__':
import sys
app = QtWidgets.QApplication(sys.argv)
w = Chess()
w.show()
sys.exit(app.exec_())
使用图形视图
结果在视觉上与前一个相同，但整体定位、绘图和交互在概念上会更容易一些，理解图形视图、场景和对象的工作方式可能需要一些时间才能掌握
from PyQt5 import QtCore, QtGui, QtWidgets
class Square(QtWidgets.QGraphicsWidget):
def __init__(self, color):
super().__init__()
if color:
self.color = QtCore.Qt.white
else:
self.color = QtCore.Qt.black
def paint(self, qp, option, widget):
qp.fillRect(option.rect, self.color)
class Scene(QtWidgets.QGraphicsScene):
def __init__(self):
super().__init__()
self.container = QtWidgets.QGraphicsWidget()
layout = QtWidgets.QGraphicsGridLayout(self.container)
layout.setSpacing(0)
self.container.setContentsMargins(0, 0, 0, 0)
layout.setContentsMargins(0, 0, 0, 0)
self.addItem(self.container)
for row in range(8):
for column in range(8):
square = Square(not (row + column) & 1)
layout.addItem(square, row, column, 1, 1)
class Board(QtWidgets.QGraphicsView):
def __init__(self):
super().__init__()
scene = Scene()
self.setScene(scene)
self.setAlignment(QtCore.Qt.AlignCenter)
# by default a graphics view has a border frame, disable it
self.setFrameShape(0)
# make it transparent
self.setStyleSheet('QGraphicsView {background: transparent;}')
def resizeEvent(self, event):
super().resizeEvent(event)
# zoom the contents keeping the ratio
self.fitInView(self.scene().container, QtCore.Qt.KeepAspectRatio)
class Chess(QtWidgets.QWidget):
def __init__(self):
super().__init__()
layout = QtWidgets.QGridLayout(self)
header = QtWidgets.QLabel('Some {}long label'.format('very ' * 20))
layout.addWidget(header, 0, 0, 1, 3, QtCore.Qt.AlignCenter)
self.board = Board()
layout.addWidget(self.board, 1, 1)
leftLayout = QtWidgets.QVBoxLayout()
layout.addLayout(leftLayout, 1, 0)
rightLayout = QtWidgets.QVBoxLayout()
layout.addLayout(rightLayout, 1, 2)
for b in range(1, 9):
leftLayout.addWidget(QtWidgets.QPushButton('Left Btn {}'.format(b)))
rightLayout.addWidget(QtWidgets.QPushButton('Right Btn {}'.format(b)))
footer = QtWidgets.QLabel('Another {}long label'.format('very ' * 18))
layout.addWidget(footer, 2, 0, 1, 3, QtCore.Qt.AlignCenter)
if __name__ == '__main__':
import sys
app = QtWidgets.QApplication(sys.argv)
w = Chess()
w.show()
sys.exit(app.exec_())
我想用方形小部件做板。当我 运行 编写代码时，它创建了漂亮的板，但在调整大小后它变得很难看。我正在尝试使用 resize Event 调整它的大小，但它存在（可能存在一些错误）。我不知道如何在调整 parent.
后调整 children 的大小Children 小部件必须是正方形所以这也是一个问题，因为我不能使用自动扩展。也许这是简单的问题，但我找不到解决方案。我花了几个小时测试不同的想法，但它现在可以正常工作了。
这是我想要调整大小的（点击最大化）：
最大化后它看起来很难看（我应该更改 children 小部件但是在什么事件上（我认为在 resizeEvent 上但它不起作用）以及如何（从 parent 或 [=56= 设置] 导致程序退出）。
这是我的最小化代码：
import logging
import sys
from PyQt5 import QtCore, QtGui
from PyQt5.QtCore import QSize
from PyQt5.QtGui import QFont, QPaintEvent, QPainter
from PyQt5.QtWidgets import QApplication, QWidget, QGridLayout
class Application(QApplication):
pass
class Board(QWidget):
def square_size(self):
size = self.size()
min_size = min(size.height(), size.width())
min_size_1_8 = min_size // 8
square_size = QSize(min_size_1_8, min_size_1_8)
logging.debug(square_size)
return square_size
def __init__(self, parent=None):
super().__init__(parent=parent)
square_size = self.square_size()
grid = QGridLayout()
grid.setSpacing(0)
squares = []
for x in range(8):
for y in range(8):
square = Square(self, (x + y - 1) % 2)
squares.append(squares)
square.setFixedSize(square_size)
grid.addWidget(square, x, y)
self.squares = squares
self.setLayout(grid)
def resizeEvent(self, event: QtGui.QResizeEvent) -> None:
# how to resize children?
logging.debug('Resize %s.', self.__class__.__name__)
logging.debug('Size %s.', event.size())
super().resizeEvent(event)
class Square(QWidget):
def __init__(self, parent, color):
super().__init__(parent=parent)
if color:
self.color = QtCore.Qt.white
else:
self.color = QtCore.Qt.black
def resizeEvent(self, event: QtGui.QResizeEvent) -> None:
logging.debug('Resize %s.', self.__class__.__name__)
logging.debug('Size %s.', event.size())
super().resizeEvent(event)
def paintEvent(self, event: QPaintEvent) -> None:
painter = QPainter()
painter.begin(self)
painter.fillRect(self.rect(), self.color)
painter.end()
def main():
logging.basicConfig(level=logging.DEBUG)
app = Application(sys.argv)
app.setAttribute(QtCore.Qt.AA_EnableHighDpiScaling, True)
default_font = QFont()
default_font.setPointSize(12)
app.setFont(default_font)
board = Board()
board.setWindowTitle('Board')
# ugly look
# chessboard.showMaximized()
# looks nize but resize not works
board.show()
sys.exit(app.exec())
if __name__ == '__main__':
main()
我应该如何调整正方形 children 的大小以避免空洞？
第二次尝试 - 改进了代码，但我仍然不知道如何调整大小 children
一些居中的新想法效果更好（现在没有间隙）但我仍然不知道如何调整大小 children（不会崩溃）。
显示后():
太宽（保持比例）：
太高（保持比例）：
更大（它保持比例但 children 未缩放到自由 space - 我仍然不知道如何调整 children 大小？）：
改进代码：
import logging
import sys
from PyQt5 import QtCore, QtGui
from PyQt5.QtCore import QSize
from PyQt5.QtGui import QFont, QPaintEvent, QPainter
from PyQt5.QtWidgets import QApplication, QWidget, QGridLayout, QHBoxLayout, QVBoxLayout
class Application(QApplication):
pass
class Board(QWidget):
def square_size(self):
size = self.size()
min_size = min(size.height(), size.width())
min_size_1_8 = min_size // 8
square_size = QSize(min_size_1_8, min_size_1_8)
logging.debug(square_size)
return square_size
def __init__(self, parent=None):
super().__init__(parent=parent)
square_size = self.square_size()
vertical = QVBoxLayout()
horizontal = QHBoxLayout()
grid = QGridLayout()
grid.setSpacing(0)
squares = []
for x in range(8):
for y in range(8):
square = Square(self, (x + y - 1) % 2)
squares.append(squares)
square.setFixedSize(square_size)
grid.addWidget(square, x, y)
self.squares = squares
horizontal.addStretch()
horizontal.addLayout(grid)
horizontal.addStretch()
vertical.addStretch()
vertical.addLayout(horizontal)
vertical.addStretch()
self.setLayout(vertical)
def resizeEvent(self, event: QtGui.QResizeEvent) -> None:
# how to resize children?
logging.debug('Resize %s.', self.__class__.__name__)
logging.debug('Size %s.', event.size())
super().resizeEvent(event)
class Square(QWidget):
def __init__(self, parent, color):
super().__init__(parent=parent)
if color:
self.color = QtCore.Qt.white
else:
self.color = QtCore.Qt.black
def resizeEvent(self, event: QtGui.QResizeEvent) -> None:
logging.debug('Resize %s.', self.__class__.__name__)
logging.debug('Size %s.', event.size())
super().resizeEvent(event)
def paintEvent(self, event: QPaintEvent) -> None:
painter = QPainter()
painter.begin(self)
painter.fillRect(self.rect(), self.color)
painter.end()
def main():
logging.basicConfig(level=logging.DEBUG)
app = Application(sys.argv)
app.setAttribute(QtCore.Qt.AA_EnableHighDpiScaling, True)
default_font = QFont()
default_font.setPointSize(12)
app.setFont(default_font)
board = Board()
board.setWindowTitle('Board')
# ugly look
# chessboard.showMaximized()
# looks nice but resize not works
board.show()
sys.exit(app.exec())
if __name__ == '__main__':
main()
如何在不崩溃的情况下调整方形 children 的大小？
有两种可能的解决方案。
您可以使用 Graphics View framework，它专门用于必须考虑 custom/specific 图形和定位的此类应用程序，否则请创建布局子类。
虽然在这种情况下重新实现布局稍微简单一些，但一旦应用程序变得更加复杂，您可能会遇到一些问题。另一方面，Graphics View 框架的学习曲线陡峭，因为您需要了解它的工作原理以及对象交互的行为方式。
子类布局
假设平方数始终相同，您可以重新实现自己的布局，根据其内容设置正确的几何形状。
在这个例子中，我还创建了一个 "container" 和其他小部件来显示正在调整大小。
当window宽度很高时，会以高度为参考，水平居中：
反之，高度越大，垂直居中：
请记住，您应该不向看板添加其他小部件，否则您会遇到严重的问题。
这并非不可能，但它的实现可能要复杂得多，因为布局需要考虑其他小部件的位置、尺寸提示和可能的扩展方向，以便正确计算新的几何形状。
from PyQt5 import QtCore, QtGui, QtWidgets
class Square(QtWidgets.QWidget):
def __init__(self, parent, color):
super().__init__(parent=parent)
if color:
self.color = QtCore.Qt.white
else:
self.color = QtCore.Qt.black
self.setMinimumSize(50, 50)
def paintEvent(self, event: QtGui.QPaintEvent) -> None:
painter = QtGui.QPainter(self)
painter.fillRect(self.rect(), self.color)
class EvenLayout(QtWidgets.QGridLayout):
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.setSpacing(0)
def setGeometry(self, oldRect):
# assuming that the minimum size is 50 pixel, find the minimum possible
# "extent" based on the geometry provided
minSize = max(50 * 8, min(oldRect.width(), oldRect.height()))
# create a new squared rectangle based on that size
newRect = QtCore.QRect(0, 0, minSize, minSize)
# move it to the center of the old one
newRect.moveCenter(oldRect.center())
super().setGeometry(newRect)
class Board(QtWidgets.QWidget):
def __init__(self):
super().__init__()
self.setSizePolicy(QtWidgets.QSizePolicy.Expanding, QtWidgets.QSizePolicy.Expanding)
layout = EvenLayout(self)
self.squares = []
for row in range(8):
for column in range(8):
square = Square(self, not (row + column) & 1)
self.squares.append(square)
layout.addWidget(square, row, column)
class Chess(QtWidgets.QWidget):
def __init__(self):
super().__init__()
layout = QtWidgets.QGridLayout(self)
header = QtWidgets.QLabel('Some {}long label'.format('very ' * 20))
layout.addWidget(header, 0, 0, 1, 3, QtCore.Qt.AlignCenter)
self.board = Board()
layout.addWidget(self.board, 1, 1)
leftLayout = QtWidgets.QVBoxLayout()
layout.addLayout(leftLayout, 1, 0)
rightLayout = QtWidgets.QVBoxLayout()
layout.addLayout(rightLayout, 1, 2)
for b in range(1, 9):
leftLayout.addWidget(QtWidgets.QPushButton('Left Btn {}'.format(b)))
rightLayout.addWidget(QtWidgets.QPushButton('Right Btn {}'.format(b)))
footer = QtWidgets.QLabel('Another {}long label'.format('very ' * 18))
layout.addWidget(footer, 2, 0, 1, 3, QtCore.Qt.AlignCenter)
if __name__ == '__main__':
import sys
app = QtWidgets.QApplication(sys.argv)
w = Chess()
w.show()
sys.exit(app.exec_())
使用图形视图
结果在视觉上与前一个相同，但整体定位、绘图和交互在概念上会更容易一些，理解图形视图、场景和对象的工作方式可能需要一些时间才能掌握
from PyQt5 import QtCore, QtGui, QtWidgets
class Square(QtWidgets.QGraphicsWidget):
def __init__(self, color):
super().__init__()
if color:
self.color = QtCore.Qt.white
else:
self.color = QtCore.Qt.black
def paint(self, qp, option, widget):
qp.fillRect(option.rect, self.color)
class Scene(QtWidgets.QGraphicsScene):
def __init__(self):
super().__init__()
self.container = QtWidgets.QGraphicsWidget()
layout = QtWidgets.QGraphicsGridLayout(self.container)
layout.setSpacing(0)
self.container.setContentsMargins(0, 0, 0, 0)
layout.setContentsMargins(0, 0, 0, 0)
self.addItem(self.container)
for row in range(8):
for column in range(8):
square = Square(not (row + column) & 1)
layout.addItem(square, row, column, 1, 1)
class Board(QtWidgets.QGraphicsView):
def __init__(self):
super().__init__()
scene = Scene()
self.setScene(scene)
self.setAlignment(QtCore.Qt.AlignCenter)
# by default a graphics view has a border frame, disable it
self.setFrameShape(0)
# make it transparent
self.setStyleSheet('QGraphicsView {background: transparent;}')
def resizeEvent(self, event):
super().resizeEvent(event)
# zoom the contents keeping the ratio
self.fitInView(self.scene().container, QtCore.Qt.KeepAspectRatio)
class Chess(QtWidgets.QWidget):
def __init__(self):
super().__init__()
layout = QtWidgets.QGridLayout(self)
header = QtWidgets.QLabel('Some {}long label'.format('very ' * 20))
layout.addWidget(header, 0, 0, 1, 3, QtCore.Qt.AlignCenter)
self.board = Board()
layout.addWidget(self.board, 1, 1)
leftLayout = QtWidgets.QVBoxLayout()
layout.addLayout(leftLayout, 1, 0)
rightLayout = QtWidgets.QVBoxLayout()
layout.addLayout(rightLayout, 1, 2)
for b in range(1, 9):
leftLayout.addWidget(QtWidgets.QPushButton('Left Btn {}'.format(b)))
rightLayout.addWidget(QtWidgets.QPushButton('Right Btn {}'.format(b)))
footer = QtWidgets.QLabel('Another {}long label'.format('very ' * 18))
layout.addWidget(footer, 2, 0, 1, 3, QtCore.Qt.AlignCenter)
if __name__ == '__main__':
import sys
app = QtWidgets.QApplication(sys.argv)
w = Chess()
w.show()
sys.exit(app.exec_())