PyQT5 正确的布局对齐

Question

我的PyQt5GUI有以下代码：

import sys
from PyQt5.QtWidgets import QApplication, QWidget, QCalendarWidget, QMainWindow, QGridLayout, QLayout, QTableWidget, QHeaderView, QLabel, QHBoxLayout, QVBoxLayout, QLineEdit, QComboBox
from PyQt5.QtCore import QDate, Qt
from datetime import date, datetime


class CalendarWindow(QMainWindow):
    def __init__(self, parent=None):
        super(CalendarWindow, self).__init__(parent)
        self.setUpUI()

    def setUpUI(self):
        self.setGeometry(50, 50, 1200, 700)
        # Labels
        self.label_events = QLabel(self)
        self.label_new_event = QLabel(self)
        self.label_event_name = QLabel(self)
        self.label_start_date = QLabel(self)
        self.label_repeat = QLabel(self)
        self.label_description = QLabel(self)
        # Labels parameters
        self.label_events.setAlignment(Qt.AlignCenter)
        self.label_events.setText("Wydarzenia danego dnia:")

        # self.label_new_event.setAlignment(Qt.AlignCenter)
        self.label_new_event.setText("Dodaj event:")

        self.label_event_name.setText("Nazwa eventu:")
        self.label_start_date.setText("Data eventu:")
        self.label_repeat.setText("Powtarzalno?? eventu:")
        self.label_description.setText("Opis:")
        # TextEdits
        self.text_event_name = QLineEdit(self)
        self.text_start_date = QLineEdit(self)
        self.text_description = QLineEdit(self)
        # TextEdits parameters

        # ComboBoxes
        self.combo_repeat = QComboBox(self)
        # ComboBoxes parameters
        self.combo_repeat.addItems(
            ["No", "Day", "Week", "Two weeks", "Month", "Half a year", "Year"])

        # Widgets
        self.setWindowTitle("Python Calendar App")
        self.calendar_widget = QCalendarWidget(self)
        # User date select event
        self.calendar_widget.clicked[QDate].connect(self.dateChanged)
        self.events_list_widget = QTableWidget(self)
        self.events_list_widget.setColumnCount(5)
        self.events_list_widget.setHorizontalHeaderLabels(
            ["ID", "Name", "Date", "Repetition", "Description"])
        # Columns stretched and fit
        self.events_list_widget.horizontalHeader().setSectionResizeMode(
            QHeaderView.Stretch)
        self.main_widget = QWidget(self)
        self.main_layout = QGridLayout(self.main_widget)
        self.main_layout.sizeConstraint = QLayout.SetDefaultConstraint
        self.main_layout.addWidget(self.calendar_widget, 0, 0)
        self.init_sublayouts()
        self.main_layout.addLayout(self.sublayout_events, 0, 1)
        self.main_layout.addLayout(self.sublayout_new_event, 0, 2)
        self.main_layout.setColumnStretch(0, 1)
        self.main_layout.setColumnStretch(1, 3)
        self.main_layout.setColumnStretch(2, 2)
        self.main_widget.setLayout(self.main_layout)
        self.setCentralWidget(self.main_widget)

    def init_sublayouts(self):
        # Events sublayout
        self.sublayout_events = QVBoxLayout()
        self.sublayout_events.addWidget(self.label_events)
        self.sublayout_events.addWidget(self.events_list_widget)
        # New event sublayout
        self.sublayout_new_event = QVBoxLayout()
        self.sublayout_new_event.addWidget(self.label_new_event)
        self.sublayout_new_event_grid = QGridLayout()
        self.sublayout_new_event_grid.addWidget(self.label_event_name, 1, 0)
        self.sublayout_new_event_grid.addWidget(self.text_event_name, 1, 1)
        self.sublayout_new_event_grid.addWidget(self.label_start_date, 2, 0)
        self.sublayout_new_event_grid.addWidget(self.text_start_date, 2, 1)
        self.sublayout_new_event_grid.addWidget(self.label_repeat, 3, 0)
        self.sublayout_new_event_grid.addWidget(self.combo_repeat, 3, 1)
        self.sublayout_new_event_grid.addWidget(self.label_description, 4, 0)
        self.sublayout_new_event_grid.addWidget(self.text_description, 4, 1)
        self.sublayout_new_event.addLayout(self.sublayout_new_event_grid)

    def dateChanged(self, qdate):
        print("Date changed to:", self.getDaysEvents())
        selected_date = self.getDaysEvents()
        # self.events_list_widget.addItem(selected_date.strftime("%d/%m/%y"))

    def getDaysEvents(self):
        selected_date = self.calendar_widget.selectedDate()
        return selected_date.toPyDate()


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

当你启动它时，它看起来像这样：

我对第三列有问题。我希望Dodaj event:标签位于顶部，而那些带有标签的文本框位于其下方不远处。相关的代码是在init_sublayouts下面# New event sublayout评论。我试图使这些文本框成QGridLayout和Dodaj event，这QGridLayout对QVBoxLabout，但你看看发生了什么。我还尝试使我QGridLayout的每一行都成为一个单独的QHBoxLayout，结果几乎相同。有没有办法做到这一点？我在第 2 列中做了类似的事情，我QLabel在 顶部堆叠了一个QTableWidget，但在第 3 列中它似乎没有按预期工作。

Answer 1

void QBoxLayout::addStretch(int stretch = 0) 添加一个最小尺寸和拉伸因子为 0 的可拉伸空间（一个 QSpacerItem）到这个盒子布局的末尾。

尝试一下：

import sys
from PyQt5.QtWidgets import QApplication, QWidget, QCalendarWidget, QMainWindow, QGridLayout, QLayout, QTableWidget, QHeaderView, QLabel, QHBoxLayout, QVBoxLayout, QLineEdit, QComboBox
from PyQt5.QtCore import QDate, Qt
from datetime import date, datetime


class CalendarWindow(QMainWindow):
    def __init__(self, parent=None):
        super(CalendarWindow, self).__init__(parent)
        self.setUpUI()

    def setUpUI(self):
        self.setGeometry(50, 50, 1200, 700)
        # Labels
        self.label_events = QLabel(self)
        self.label_new_event = QLabel(self)
        self.label_event_name = QLabel(self)
        self.label_start_date = QLabel(self)
        self.label_repeat = QLabel(self)
        self.label_description = QLabel(self)
        # Labels parameters
        self.label_events.setAlignment(Qt.AlignCenter)
        self.label_events.setText("Wydarzenia danego dnia:")

        self.label_new_event.setAlignment(Qt.AlignCenter)         # +
        self.label_new_event.setText("Dodaj event:")

        self.label_event_name.setText("Nazwa eventu:")
        self.label_start_date.setText("Data eventu:")
        self.label_repeat.setText("Powtarzalno?? eventu:")
        self.label_description.setText("Opis:")
        # TextEdits
        self.text_event_name = QLineEdit(self)
        self.text_start_date = QLineEdit(self)
        self.text_description = QLineEdit(self)
        # TextEdits parameters

        # ComboBoxes
        self.combo_repeat = QComboBox(self)
        # ComboBoxes parameters
        self.combo_repeat.addItems(
            ["No", "Day", "Week", "Two weeks", "Month", "Half a year", "Year"])

        # Widgets
        self.setWindowTitle("Python Calendar App")
        self.calendar_widget = QCalendarWidget(self)
        # User date select event
        self.calendar_widget.clicked[QDate].connect(self.dateChanged)
        self.events_list_widget = QTableWidget(self)
        self.events_list_widget.setColumnCount(5)
        self.events_list_widget.setHorizontalHeaderLabels(
            ["ID", "Name", "Date", "Repetition", "Description"])
        # Columns stretched and fit
        self.events_list_widget.horizontalHeader().setSectionResizeMode(
            QHeaderView.Stretch)
        self.main_widget = QWidget(self)
        self.main_layout = QGridLayout(self.main_widget)
        self.main_layout.sizeConstraint = QLayout.SetDefaultConstraint
        self.main_layout.addWidget(self.calendar_widget, 0, 0)
        self.init_sublayouts()
        self.main_layout.addLayout(self.sublayout_events, 0, 1)
        self.main_layout.addLayout(self.sublayout_new_event, 0, 2)
        self.main_layout.setColumnStretch(0, 1)
        self.main_layout.setColumnStretch(1, 3)
        self.main_layout.setColumnStretch(2, 2)
        self.main_widget.setLayout(self.main_layout)
        self.setCentralWidget(self.main_widget)

    def init_sublayouts(self):
        # Events sublayout
        self.sublayout_events = QVBoxLayout()
        self.sublayout_events.addWidget(self.label_events)
        self.sublayout_events.addWidget(self.events_list_widget)
        # New event sublayout
        self.sublayout_new_event = QVBoxLayout()
        self.sublayout_new_event.addWidget(self.label_new_event)
        self.sublayout_new_event.addStretch(1)                            # +

        self.sublayout_new_event_grid = QGridLayout()
        self.sublayout_new_event_grid.addWidget(self.label_event_name, 1, 0)
        self.sublayout_new_event_grid.addWidget(self.text_event_name, 1, 1)
        self.sublayout_new_event_grid.addWidget(self.label_start_date, 2, 0)
        self.sublayout_new_event_grid.addWidget(self.text_start_date, 2, 1)
        self.sublayout_new_event_grid.addWidget(self.label_repeat, 3, 0)
        self.sublayout_new_event_grid.addWidget(self.combo_repeat, 3, 1)
        self.sublayout_new_event_grid.addWidget(self.label_description, 4, 0)
        self.sublayout_new_event_grid.addWidget(self.text_description, 4, 1)
        self.sublayout_new_event.addLayout(self.sublayout_new_event_grid)
        self.sublayout_new_event.addStretch(20)                            # +

    def dateChanged(self, qdate):
        print("Date changed to:", self.getDaysEvents())
        selected_date = self.getDaysEvents()
        # self.events_list_widget.addItem(selected_date.strftime("%d/%m/%y"))

    def getDaysEvents(self):
        selected_date = self.calendar_widget.selectedDate()
        return selected_date.toPyDate()


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