通过按钮打开字体选择对话框，将选择好的字体，赋值给Label标签，以此来改变字体的大小

"""
字体对话框 QFontDialog
"""

import sys
from PyQt5.QtCore import *
from PyQt5.QtGui import *
from PyQt5.QtWidgets import *
from PyQt5.QtCore import Qt

class QFontDialogDemo(QWidget):
    def __init__(self):
        super(QFontDialogDemo, self).__init__()
        self.initUI()

    def initUI(self):
        self.setWindowTitle("Font Dialog例子")
        layout = QVBoxLayout()
        self.fontButton = QPushButton('选择字体')
        self.fontButton.clicked.connect(self.getFont)
        layout.addWidget(self.fontButton)

        self.fontLabel = QLabel("Hello, 测试字体例子")
        layout.addWidget(self.fontLabel)

        self.setLayout(layout)

    def getFont(self):
        #获得选择好的字体类型和大小
        font, ok =  QFontDialog.getFont()
        if ok:
            #将获得的字体大小赋值给标签, 进行字体的改变
            self.fontLabel.setFont(font)

if __name__ == "__main__":
    app = QApplication(sys.argv)

    main = QFontDialogDemo()
    main.show()

    sys.exit(app.exec_())

主界面

 

字体对话框(QFontDialog.getFont())