Question

我在qt设计器的帮助下制作了一个简单的mainWindow，并使用cmd中的pyuic5选项获得了完整的代码。我将此行添加到主要部分：

QtCore.QCoreApplication.setAttribute(QtCore.Qt.AA_EnableHighDpiScaling)

以便能够正确看到我的窗口（没有整个窗口）。

在qt designer内的属性中，我更改了sizePolicy值以进行扩展，但是当我尝试运行我的应用程序时，sizePolicy无法正常工作，它全部留在了左上角。

这是我从pyuic5获得的代码：

from PyQt5 import QtCore, QtGui, QtWidgets


class Ui_CompanyCommanderLogin(object):
    def setupUi(self, CompanyCommanderLogin):
        CompanyCommanderLogin.setObjectName("CompanyCommanderLogin")
        CompanyCommanderLogin.resize(252, 227)
        sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Expanding, QtWidgets.QSizePolicy.Expanding)
        sizePolicy.setHorizontalStretch(0)
        sizePolicy.setVerticalStretch(0)
        sizePolicy.setHeightForWidth(CompanyCommanderLogin.sizePolicy().hasHeightForWidth())
        CompanyCommanderLogin.setSizePolicy(sizePolicy)
        self.centralwidget = QtWidgets.QWidget(CompanyCommanderLogin)
        self.centralwidget.setObjectName("centralwidget")
        self.groupBox = QtWidgets.QGroupBox(self.centralwidget)
        self.groupBox.setGeometry(QtCore.QRect(10, 10, 231, 171))
        self.groupBox.setObjectName("groupBox")
        self.label = QtWidgets.QLabel(self.groupBox)
        self.label.setGeometry(QtCore.QRect(20, 40, 71, 16))
        self.label.setObjectName("label")
        self.label_3 = QtWidgets.QLabel(self.groupBox)
        self.label_3.setGeometry(QtCore.QRect(20, 70, 41, 16))
        self.label_3.setObjectName("label_3")
        self.label_4 = QtWidgets.QLabel(self.groupBox)
        self.label_4.setGeometry(QtCore.QRect(20, 100, 41, 16))
        self.label_4.setObjectName("label_4")
        self.lineEdit_x_location = QtWidgets.QLineEdit(self.groupBox)
        self.lineEdit_x_location.setGeometry(QtCore.QRect(100, 70, 51, 20))
        self.lineEdit_x_location.setObjectName("lineEdit_x_location")
        self.lineEdit_y_location = QtWidgets.QLineEdit(self.groupBox)
        self.lineEdit_y_location.setGeometry(QtCore.QRect(100, 100, 51, 20))
        self.lineEdit_y_location.setObjectName("lineEdit_y_location")
        self.pushButton_login = QtWidgets.QPushButton(self.groupBox)
        self.pushButton_login.setGeometry(QtCore.QRect(140, 140, 71, 21))
        self.pushButton_login.setStyleSheet("background-color: rgb(0, 209, 255);\n"
"color: rgb(255, 255, 255);\n"
"background-color: rgb(0, 0, 127);")
        self.pushButton_login.setObjectName("pushButton_login")
        self.comboBox = QtWidgets.QComboBox(self.groupBox)
        self.comboBox.setGeometry(QtCore.QRect(100, 40, 51, 21))
        self.comboBox.setObjectName("comboBox")
        CompanyCommanderLogin.setCentralWidget(self.centralwidget)
        self.menubar = QtWidgets.QMenuBar(CompanyCommanderLogin)
        self.menubar.setGeometry(QtCore.QRect(0, 0, 252, 18))
        self.menubar.setObjectName("menubar")
        CompanyCommanderLogin.setMenuBar(self.menubar)
        self.statusbar = QtWidgets.QStatusBar(CompanyCommanderLogin)
        self.statusbar.setObjectName("statusbar")
        CompanyCommanderLogin.setStatusBar(self.statusbar)

        self.retranslateUi(CompanyCommanderLogin)
        QtCore.QMetaObject.connectSlotsByName(CompanyCommanderLogin)

    def retranslateUi(self, CompanyCommanderLogin):
        _translate = QtCore.QCoreApplication.translate
        CompanyCommanderLogin.setWindowTitle(_translate("CompanyCommanderLogin", "Company Commander Login"))
        self.groupBox.setTitle(_translate("CompanyCommanderLogin", "Login"))
        self.label.setText(_translate("CompanyCommanderLogin", "<html><head/><body><p><span style=\" font-size:9pt;\">Company Number:</span></p></body></html>"))
        self.label_3.setText(_translate("CompanyCommanderLogin", "<html><head/><body><p><span style=\" font-size:9pt;\">X Location:</span></p></body></html>"))
        self.label_4.setText(_translate("CompanyCommanderLogin", "<html><head/><body><p><span style=\" font-size:9pt;\">Y Location:</span></p></body></html>"))
        self.pushButton_login.setText(_translate("CompanyCommanderLogin", "Login"))


if __name__ == "__main__":
    import sys
    QtCore.QCoreApplication.setAttribute(QtCore.Qt.AA_EnableHighDpiScaling)
    app = QtWidgets.QApplication(sys.argv)
    CompanyCommanderLogin = QtWidgets.QMainWindow()
    ui = Ui_CompanyCommanderLogin()
    ui.setupUi(CompanyCommanderLogin)
    CompanyCommanderLogin.show()
    sys.exit(app.exec_())

sizePolicy可能是什么问题？有没有其他方法可以使mainWindow扩展？

例如图片（此处登录位于左上角，我希望它是整个窗口的大小）

Answer 1

the docs指出：

小部件的大小策略是其以各种方式调整大小的意愿的表达，并且会影响layout engine对小部件的处理方式。每个窗口小部件都返回一个QSizePolicy，该页面描述了布局时首选的水平和垂直大小调整策略。您可以通过更改特定窗口小部件的QWidget::sizePolicy属性来对其进行更改。

QSizePolicy仅在布局中起作用，而在您的情况下则没有。

因此解决方案是使用QXLayout创建设计，如果要在Qt Designer中使用它，则应阅读Qt Designer Manual，尤其是Using Layouts in Qt Designer部分。

在这种情况下，由于您没有提供允许我使用Qt Designer的.ui，因此我将迅速从头开始提供解决方案

from PyQt5 import QtCore, QtGui, QtWidgets


class CompanyCommanderLogin(QtWidgets.QMainWindow):
    def __init__(self, parent=None):
        super().__init__(parent)

        self.groupbox = QtWidgets.QGroupBox(self.tr("Login"))
        self.company_cb = QtWidgets.QComboBox()
        sp = self.company_cb.sizePolicy()
        sp.setHorizontalPolicy(QtWidgets.QSizePolicy.Expanding)
        self.company_cb.setSizePolicy(sp)
        self.xlocation_le = QtWidgets.QLineEdit()
        self.ylocation_le = QtWidgets.QLineEdit()
        self.login_button = QtWidgets.QPushButton(self.tr("Login"))
        self.login_button.setStyleSheet(
            "background-color: rgb(0, 209, 255);\n"
            "color: rgb(255, 255, 255);\n"
            "background-color: rgb(0, 0, 127);"
        )

        font = self.font()
        font.setPointSize(9)
        self.setFont(font)

        central_widget = QtWidgets.QWidget()
        self.setCentralWidget(central_widget)
        lay = QtWidgets.QVBoxLayout(central_widget)
        lay.addWidget(self.groupbox)

        flay = QtWidgets.QFormLayout()

        flay.addRow(
            self.tr("Company Number:"), self.company_cb,
        )
        flay.addRow(
            self.tr("X Location:"), self.xlocation_le,
        )
        flay.addRow(
            self.tr("Y Location:"), self.ylocation_le,
        )

        lay = QtWidgets.QVBoxLayout()
        lay.addLayout(flay)
        lay.addWidget(self.login_button, alignment=QtCore.Qt.AlignHCenter)
        lay.addStretch()
        self.groupbox.setLayout(lay)


if __name__ == "__main__":
    import sys

    if hasattr(QtCore.Qt, "AA_EnableHighDpiScaling"):
        QtCore.QCoreApplication.setAttribute(QtCore.Qt.AA_EnableHighDpiScaling)

    app = QtWidgets.QApplication(sys.argv)
    w = CompanyCommanderLogin()
    w.show()
    sys.exit(app.exec_())

如何设置mainWindow的sizePolicy？

1 个答案: