PyQT5 正确的布局对齐

Posted 2023-03-30

【中文标题】PyQT5 正确的布局对齐

【英文标题】：PyQT5 proper layout alignment

【发布时间】：2018-04-21 18:42:34

【问题描述】：

我的PyQt5 GUI 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("Powtarzalność 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 3 列有疑问。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。相关代码在init_sublayouts# New event sublayout注释下。我试图将这些文本框变成QGridLayout 和Dodaj event 和这个QGridLayout 到QVBoxLabout，但你看到发生了什么。我还尝试将我的QGridLayout 的每一行都设为单独的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，我在 QTableWidget 上堆叠了一个 QLabel，但在第 3 列中它似乎没有按预期工作。

【参考方案1】：

void QBoxLayout::addStretch(int stretch = 0) 将最小尺寸为零且拉伸因子拉伸的可拉伸空间（QSpacerItem）添加到此框布局的末尾。

试试看：

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("Powtarzalność 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_())