首先是界面的布置，代码如下所示，使用的是Designer。

1. # -*- coding: utf-8 -*-

2.  

3. # Form implementation generated from reading ui file 'untitled.ui'

4. #

5. # Created by: PyQt5 UI code generator 5.6

6. #

7. # WARNING! All changes made in this file will be lost!

8.  

9. from PyQt5 import QtCore, QtGui, QtWidgets

10.  

11. class Ui_MainWindow(object):

12. def setupUi(self, MainWindow):

13. MainWindow.setObjectName("MainWindow")

14. MainWindow.resize(800, 600)

15. self.centralwidget = QtWidgets.QWidget(MainWindow)

16. self.centralwidget.setObjectName("centralwidget")

17. self.btn_1 = QtWidgets.QPushButton(self.centralwidget)

18. self.btn_1.setGeometry(QtCore.QRect(220, 191, 75, 23))

19. self.btn_1.setObjectName("btn_1")

20. self.btn_2 = QtWidgets.QPushButton(self.centralwidget)

21. self.btn_2.setGeometry(QtCore.QRect(220, 220, 75, 23))

22. self.btn_2.setObjectName("btn_2")

23. self.btn_3 = QtWidgets.QPushButton(self.centralwidget)

24. self.btn_3.setGeometry(QtCore.QRect(220, 249, 75, 23))

25. self.btn_3.setObjectName("btn_3")

26. self.btn_4 = QtWidgets.QPushButton(self.centralwidget)

27. self.btn_4.setGeometry(QtCore.QRect(220, 278, 75, 23))

28. self.btn_4.setObjectName("btn_4")

29. self.label = QtWidgets.QLabel(self.centralwidget)

30. self.label.setGeometry(QtCore.QRect(310, 190, 71, 101))

31. font = QtGui.QFont()

32. font.setFamily("Arial")

33. font.setPointSize(36)

34. self.label.setFont(font)

35. self.label.setAlignment(QtCore.Qt.AlignCenter)

36. self.label.setObjectName("label")

37. self.btn_exit = QtWidgets.QPushButton(self.centralwidget)

38. self.btn_exit.setGeometry(QtCore.QRect(220, 330, 75, 23))

39. self.btn_exit.setObjectName("btn_exit")

40. MainWindow.setCentralWidget(self.centralwidget)

41. self.menubar = QtWidgets.QMenuBar(MainWindow)

42. self.menubar.setGeometry(QtCore.QRect(0, 0, 800, 23))

43. self.menubar.setObjectName("menubar")

44. MainWindow.setMenuBar(self.menubar)

45. self.statusbar = QtWidgets.QStatusBar(MainWindow)

46. self.statusbar.setObjectName("statusbar")

47. MainWindow.setStatusBar(self.statusbar)

48.  

49. self.retranslateUi(MainWindow)

50. QtCore.QMetaObject.connectSlotsByName(MainWindow)

51.  

52. def retranslateUi(self, MainWindow):

53. _translate = QtCore.QCoreApplication.translate

54. MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))

55. self.btn_1.setText(_translate("MainWindow", "1"))

56. self.btn_2.setText(_translate("MainWindow", "2"))

57. self.btn_3.setText(_translate("MainWindow", "3"))

58. self.btn_4.setText(_translate("MainWindow", "4"))

59. self.label.setText(_translate("MainWindow", "0"))

60. self.btn_exit.setText(_translate("MainWindow", "退出"))

61.  

接下来是运行代码，如下所示：

1. # -*- coding: utf-8 -*-

2. '''

3. 通过按钮改变Label的背景颜色

4. '''

5. import os

6. import sys

7. import time

8. from tqdm import tqdm

9. from PyQt5.QtWidgets import QApplication, QWidget, QMessageBox, QMainWindow

10. from PyQt5.QtGui import QPalette

11. from PyQt5.QtCore import Qt

12. from application.NewUi.untitled import Ui_MainWindow

13.  
14.  

15. class my_window(Ui_MainWindow, QMainWindow):

16. def __init__(self):

17. super(my_window, self).__init__()

18. self.setupUi(self)

19. self.label.setAutoFillBackground(True)

20. global palette_red, palette_green, palette_blue, palette_yellow

21. palette_red = QPalette()

22. palette_green = QPalette()

23. palette_blue = QPalette()

24. palette_yellow = QPalette()

25. palette_red.setColor(QPalette.Window, Qt.red)

26. palette_green.setColor(QPalette.Window, Qt.green)

27. palette_blue.setColor(QPalette.Window, Qt.blue)

28. palette_yellow.setColor(QPalette.Window, Qt.yellow)

29. self.btn_1.clicked.connect(self.btn_1_clicked)

30. self.btn_2.clicked.connect(self.btn_2_clicked)

31. self.btn_3.clicked.connect(self.btn_3_clicked)

32. self.btn_4.clicked.connect(self.btn_4_clicked)

33. self.btn_exit.clicked.connect(self.exit_systerm)

34. self.setWindowTitle('通过按钮改变Label的背景颜色')

35.  

36. def btn_1_clicked(self):

37. self.label.setPalette(palette_red)

38.  

39. def btn_2_clicked(self):

40. self.label.setPalette(palette_blue)

41.  

42. def btn_3_clicked(self):

43. self.label.setPalette(palette_green)

44.  

45. def btn_4_clicked(self):

46. self.label.setPalette(palette_yellow)

47.  

48. def exit_systerm(self):

49. self.close()

50.  

51. def closeEvent(self, event):

52. reply = QMessageBox.question(self, 'Exit', 'Are you sure to quit?', QMessageBox.Yes | QMessageBox.Cancel)

53. if reply == QMessageBox.Yes:

54. event.accept()

55. else:

56. event.ignore()

57.  
58.  

59. if __name__ == '__main__':

60. app = QApplication(sys.argv)

61. w = my_window()

62. w.show()

63. sys.exit(app.exec_())

64.  

特别注意：一定要在想要变色的控件下面加上这句话self.label.setAutoFillBackground(True)

其中标红的地方是你控件的id，如果不加这句话是不能变色的。

文章来源: blog.csdn.net，作者：网奇，版权归原作者所有，如需转载，请联系作者。

原文链接：blog.csdn.net/jacke121/article/details/108327378