[[oktatas:programozás:python:python_qt|< Python Qt]]

====== Qt kezdés ======

  * **Szerző:** Sallai András
  * Copyright (c) 2021, Sallai András
  * Licenc: [[https://creativecommons.org/licenses/by-sa/4.0/|CC BY-SA 4.0]]
  * Web: https://szit.hu

===== Helló Világ =====

<code python hello.py>
import sys
from PyQt5.QtWidgets import QApplication, QMainWindow

class MainWindow(QMainWindow):

    def __init__(self):
        super().__init__()

        self.setGeometry(100,100,320,200)
        self.setWindowTitle('Helló Világ')
        self.show()

if __name__ == '__main__':
    app = QApplication(sys.argv)
    mainWindow = MainWindow()
    sys.exit(app.exec_())
</code>


===== Felirat =====

<code python label.py>
import sys
from PyQt5.QtWidgets import QApplication, QMainWindow
from PyQt5.QtWidgets import QLabel


class MainWindow(QMainWindow):

    def __init__(self):
        super().__init__()

        helloLabel = QLabel(self)
        helloLabel.setText('Működik')
        helloLabel.move(120, 90)        

        self.setGeometry(100,100,320,200)
        self.setWindowTitle('Helló Világ')
        self.show()

if __name__ == '__main__':
    app = QApplication(sys.argv)
    mainWindow = MainWindow()
    sys.exit(app.exec_())
</code>

===== Gomb eseménnyel =====


<code python gomb.py>
import sys
from PyQt5.QtWidgets import QApplication, QMainWindow, QPushButton

class MainWindow(QMainWindow):

    def __init__(self):
        super().__init__()

        button1 = QPushButton(self)
        button1.setText("Mehet")
        button1.move(50, 100)
        button1.clicked.connect(self.on_click_button1)

        self.setGeometry(100,100,320,200)
        self.show()
    

    def on_click_button1(self):    
        self.setWindowTitle('egy')

if __name__ == '__main__':
    app = QApplication(sys.argv)
    mainWindow = MainWindow()
    sys.exit(app.exec_())
</code>

===== Beviteli mező =====

<code python bevitel.py>
import sys
from PyQt5.QtWidgets import QApplication, QMainWindow, QPushButton, QLineEdit

class MainWindow(QMainWindow):

    def __init__(self):
        super().__init__()

        button1 = QPushButton(self)
        button1.setText("Mehet")
        button1.move(50, 100)
        button1.clicked.connect(self.on_click_button1)

        self.entry1 = QLineEdit(self)
        self.entry1.move(50, 60)

        self.setGeometry(100,100,320,200)
        self.setWindowTitle("Helló Világ")
        self.show()
    

    def on_click_button1(self):    
        text1 = self.entry1.text()
        self.setWindowTitle(text1)

if __name__ == '__main__':
    app = QApplication(sys.argv)
    mainWindow = MainWindow()
    sys.exit(app.exec_())
</code>


===== Gyakorlat =====

==== triangle.py ====

  * Írjon programot, amely bekéri egy háromszög alapját és magasságát, majd kiszámítja a területét.


<code python triangle.py>
import sys
from PyQt5.QtWidgets import QApplication, QMainWindow
from PyQt5.QtWidgets import QLabel, QLineEdit, QPushButton


class MainWindow(QMainWindow):

    def __init__(self):
        super().__init__()

        baseLabel = QLabel(self)
        baseLabel.setText('Alap')
        baseLabel.move(50, 30)
        self.baseEntry = QLineEdit(self)
        self.baseEntry.move(130, 30)

        heightLabel = QLabel(self)
        heightLabel.setText('Magasság')
        heightLabel.move(50, 70)
        self.heightEnty = QLineEdit(self)
        self.heightEnty.move(130, 70)

        calcButton = QPushButton(self)
        calcButton.setText('Számít')
        calcButton.move(90, 120)
        calcButton.clicked.connect(self.on_click_calcbutton)

        areaLabel = QLabel(self)
        areaLabel.setText('Terület')
        areaLabel.move(50, 160)

        self.areaEnty = QLineEdit(self)
        self.areaEnty.move(130, 160)

        self.setGeometry(100,100,320,200)
        self.setWindowTitle('Háromszög területe')
        self.show()

    def on_click_calcbutton(self):
        base = int(self.baseEntry.text())
        height = int(self.heightEnty.text())
        area = base * height / 2
        self.areaEnty.setText(str(area))
        self.baseEntry.setText('')
        self.heightEnty.setText('')

if __name__ == '__main__':
    app = QApplication(sys.argv)
    mainWindow = MainWindow()
    sys.exit(app.exec_())
</code>


===== ComboBox =====

<code python combo.py>
import sys
from PyQt5.QtWidgets import QApplication, QComboBox, QMainWindow
from PyQt5.QtWidgets import QComboBox


class MainWindow(QMainWindow):

    def __init__(self):
        super().__init__()
        combo = QComboBox(self)
        combo.move(50, 50)
        combo.addItem('Alma')
        combo.addItem('Körte')
        combo.addItem('Barack')
        combo.addItem('Szilva')

        self.setGeometry(100, 100, 320, 200)
        self.show()

if __name__ == '__main__':
    app = QApplication(sys.argv)
    mainWindow = MainWindow()
    sys.exit(app.exec_())
</code>