pyqt5学习笔记

一、使用qpushbutton，qlineedit，qlabel

注意：press_it不是类的方法，这样有个好处，可以直接调用所定义的变量。使用qtw和qtg表示库名的简写。

继承qmainwindow的类才有statusbar属性

import sys
import PyQt5.QtWidgets as qtw
import PyQt5.QtGui as qtg


class MainWindow(qtw.QWidget):

    def __init__(self):
        super().__init__()
        self.resize(400, 200)
        # self.status = self.statusBar()
        # self.status.showMessage("welcome to earth", 5000)
        self.setWindowTitle("hello world")

        #set layout
        ly_1 = qtw.QVBoxLayout()

        my_label = qtw.QLabel("touch me")
        my_label.setFont(qtg.QFont('Helvetica', 18))
        ly_1.addWidget(my_label)

        my_entry = qtw.QLineEdit()
        my_entry.setObjectName("name_field")
        my_entry.setText("")
        ly_1.addWidget(my_entry)

        my_button = qtw.QPushButton("Press me", clicked=lambda: press_it())
        ly_1.addWidget(my_button)

        self.setLayout(ly_1)

        #show the app
        self.show()

        def press_it():
            my_label.setText(f"hello {my_entry.text()}")
            my_entry.setText("")


if __name__ == "__main__":
    app = qtw.QApplication(sys.argv)
    form = MainWindow()
    sys.exit(app.exec())