Twenty-three --QFontDialog study concluded GUI learning

Today, learning the Font dialog box --QFontDialog () control.

QFontDialog () is inherited from a subclass QDialog () is used to select a given font (including font, size, style, etc.)

A. Constructor

QFontDialog () statement is very simple, you can directly call

f = QFontDialog ()

Another method is to specify the default font (Enabling Sample box displays the specified font)

font = QFont ()
font.setFamily ( ' Arial ' )
font.setPointSize(24)
fd = QFontDialog(font,self)

Use II. Dialog

Here we borrow a button to start the Font dialog box, and then get the Font dialog box selection.

Here is knowledge: We are in the Open dialog box when using open () is the transfer function of a trough

QFontDialog.open(self, slot: PYQT_SLOT)

After the dialog is opened, a function of automatically connecting groove signals specified here fontSelected

Method 1: using open () function, binding SelectFont () function

from PyQt5.Qt import *
import sys

class Window(QWidget):
    def __init__(self):
        super().__init__()
        self.UI_test()


    def UI_test(self):
        BTN = the QPushButton ( ' Select Font ' , Self)
        are = QFont ()
        font.setFamily ( ' Arial ' )
        font.setPointSize(24)
        fd = QFontDialog(font,self)
        self.fd = fd
        btn.clicked.connect(lambda :fd.open(self.func))
        pass

    DEF FUNC (Self, * args):
         Print ( ' font selection: ' ., self.fd.selectedFont () Family ())    # get the selected font 
IF  __name__ == ' __main__ ' :
    app = QApplication(sys.argv)
    window = Window()
    window.show()
    sys.exit(app.exec_())

Scheme 2: exec using the return value, binding SelectFont () function

from PyQt5.Qt import *
import sys

class Window(QWidget):
    def __init__(self):
        super().__init__()
        self.UI_test()


    def UI_test(self):
        BTN = the QPushButton ( ' Select Font ' , Self)
        fd = QFontDialog(self)
        def font_select():
            if fd.exec():
                print(fd.selectedFont().family())

        btn.clicked.connect(font_select)
        pass
if __name__ == '__main__':
    app = QApplication(sys.argv)
    window = Window()
    window.show()
    sys.exit(app.exec_())

Because there is a return value of exec, only click on the OK before returning 1, are canceled and closed returns 0. Only confirmed only get chosen font.

III. Setting Options

You can set buttons and other options through code

QFontDialog.setOption (Self, the Option: ' QFontDialog.FontDialogOption ' , ON: BOOL = ...)
 # FontDialogOption enumeration value 
NoButtons                    # does not display the Cancel button (useful for real-time dialog) 
DontUseNativeDialog          # using Qt on Mac Apple's standard font instead of the original forest font 
ScalableFonts                # display scalable fonts 
NonScalableFonts             # display non-scalable fonts 
MonospacedFonts              # display monospaced font 
ProportionalFonts            # display proportional fonts

We can try the first option, that is, in a real-time dialog box to select a different font and then change the font in the label in real time

from PyQt5.Qt import *
import sys

class Window(QWidget):
    def __init__(self):
        super().__init__()
        self.resize(800,500)
        self.UI_test()


    def UI_test(self):
        label = QLabel('字体',self)
        label.move(100,200)
        self.label = label
        BTN = the QPushButton ( ' Select Font ' , Self)
        are = QFont ()
        font.setFamily ( ' Arial ' )
        font.setPointSize(24)
        fd = QFontDialog(font,self)
        fd.setOption(QFontDialog.NoButtons)
        self.fd = fd
        btn.clicked.connect(lambda :fd.open(self.func))
        pass
        fd.currentFontChanged.connect(self.label_font_change)
    DEF FUNC (Self, * args):
         Print ( ' font selection: ' ., self.fd.selectedFont () Family ())    # get the selected font 
    DEF label_font_change (Self, font):
        self.label.setFont(font)
        self.label.adjustSize()
if __name__ == '__main__':
    app = QApplication(sys.argv)
    window = Window()
    window.show()
    sys.exit(app.exec_())

Real-time change the font

Of course, the above values ​​may be enumerated by pipe '|' is connected simultaneously.

IV. Static method

QFontDialog.getFont () # -> tuple

We first define a button, the button connected to this slot function

def func(self):
    result = QFontDialog.getFont()
    print(result)
    pass

Each call will find slot function result is a tuple. Tuple contains a font and a Boolean object. Just click on the OK button boolean was true. Use this method to achieve a static adjust font

from PyQt5.Qt import *
import sys

class Window(QWidget):
    def __init__(self):
        super().__init__()
        self.resize(800,500)
        self.UI_test()


    def UI_test(self):
        label = QLabel('字体',self)
        label.move(100,200)
        self.label = label
        BTN = the QPushButton ( ' Select Font ' , Self)
        btn.clicked.connect(self.func)

    def func(self):
        result = QFontDialog.getFont()
        if result[1]:
            self.label.setFont(result[0])
　　　　　　  self.label.adjustSize()
        pass

if __name__ == '__main__':
    app = QApplication(sys.argv)
    window = Window()
    window.show()
    sys.exit(app.exec_())

() There are a number of high-level usage getFont

QFontDialog (the Font, parent, ' dialog title ' , font filter)

V. signal

There are two signals, one is the current font is changed

QFontDialog.currentFontChanged(self, font: QtGui.QFont)

This is simply select the font change sends a signal (commonly used in real-time dialog, there are cases above)

QFontDialog.fontSelected(self, font: QtGui.QFont)

The determination signal is sent when pressing the key.