使用PyQt5 / Pyside2将重复的SVG模式设置为主窗口/ Qwidget背景

Question

我已经通过http://www.heropatterns.com/生成了SVG css代码，并试图将其用作我的主窗口/ Qwidget的背景。我希望随着窗口的增大或缩小来调整背景大小。我尝试用生成的css作为参数传递来调用Form.setStyleSheet（），但是我只得到了模式中的两种颜色（背景颜色）之一。将SVG显示为QWidget主窗口的背景并查看完整模式的正确方法是什么？我知道QSvgRenderer存在，但是我不确定一旦创建QSvgRenderer对象，然后从那里去使SVG成为可调整大小的背景。有人告诉我在样式表中使用background-repeat: repeat;属性，但是并没有任何改变。

这是我写的最小，完整和可验证的示例：

class Ui_Form(object):
    def setupUi(self, Form):
        Form.setObjectName("Form")
        Form.resize(400, 300)
        self.horizontalLayout_2 = QtWidgets.QHBoxLayout(Form)
        self.horizontalLayout_2.setObjectName("horizontalLayout_2")
        self.horizontalLayout = QtWidgets.QHBoxLayout()
        self.horizontalLayout.setObjectName("horizontalLayout")
        self.horizontalLayout_2.addLayout(self.horizontalLayout)
        self.retranslateUi(Form)
        Form.setStyleSheet("""background-repeat: repeat; background-color: #000000;
background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='28' height='49' viewBox='0 0 28 49'%3E%3Cg fill-rule='evenodd'%3E%3Cg id='hexagons' fill='%23b0b0b0' fill-opacity='0.4' fill-rule='nonzero'%3E%3Cpath d='M13.99 9.25l13 7.5v15l-13 7.5L1 31.75v-15l12.99-7.5zM3 17.9v12.7l10.99 6.34 11-6.35V17.9l-11-6.34L3 17.9zM0 15l12.98-7.5V0h-2v6.35L0 12.69v2.3zm0 18.5L12.98 41v8h-2v-6.85L0 35.81v-2.3zM15 0v7.5L27.99 15H28v-2.31h-.01L17 6.35V0h-2zm0 49v-8l12.99-7.5H28v2.31h-.01L17 42.15V49h-2z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");""")
        QtCore.QMetaObject.connectSlotsByName(Form)

    def retranslateUi(self, Form):
        Form.setWindowTitle(QtWidgets.QApplication.translate("Form", "Form", None, -1))


if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv)
    Form = QtWidgets.QWidget()
    ui = Ui_Form()
    ui.setupUi(Form)
    Form.show()
    sys.exit(app.exec_())

当前表单外观：

表格的外观：

SVG模式的XML表示形式

<svg xmlns="http://www.w3.org/2000/svg" width="28" height="49" viewBox="0 0 28 49"><g fill-rule="evenodd"><g id="hexagons" fill="#000" fill-rule="nonzero"><path d="M13.99 9.25l13 7.5v15l-13 7.5L1 31.75v-15l12.99-7.5zM3 17.9v12.7l10.99 6.34 11-6.35V17.9l-11-6.34L3 17.9zM0 15l12.98-7.5V0h-2v6.35L0 12.69v2.3zm0 18.5L12.98 41v8h-2v-6.85L0 35.81v-2.3zM15 0v7.5L27.99 15H28v-2.31h-.01L17 6.35V0h-2zm0 49v-8l12.99-7.5H28v2.31h-.01L17 42.15V49h-2z"/></g></g></svg>

更改按钮背景的示例：

from PySide2 import QtCore, QtGui, QtWidgets

class Ui_Form(object):
    def setupUi(self, Form):
        Form.setObjectName("Form")
        Form.resize(400, 300)
        self.horizontalLayout_2 = QtWidgets.QHBoxLayout(Form)
        self.horizontalLayout_2.setObjectName("horizontalLayout_2")
        self.horizontalLayout = QtWidgets.QHBoxLayout()
        self.horizontalLayout.setObjectName("horizontalLayout")
        self.horizontalLayout_2.addLayout(self.horizontalLayout)

        self.Start_Stop_button = QtWidgets.QPushButton(Form)
        sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Minimum, QtWidgets.QSizePolicy.Fixed)
        sizePolicy.setHorizontalStretch(0)
        sizePolicy.setVerticalStretch(0)
        sizePolicy.setHeightForWidth(self.Start_Stop_button.sizePolicy().hasHeightForWidth())
        self.Start_Stop_button.setSizePolicy(sizePolicy)
        self.Start_Stop_button.setMinimumSize(QtCore.QSize(0, 0))
        self.Start_Stop_button.setBaseSize(QtCore.QSize(0, 0))
        self.Start_Stop_button.setIconSize(QtCore.QSize(16, 16))
        self.Start_Stop_button.setFlat(False)
        self.Start_Stop_button.setObjectName("Start_Stop_button")
        contents = b"<svg xmlns='http://www.w3.org/2000/svg' width='28' height='49' viewBox='0 0 28 49'><g fill-rule='evenodd'><g id='hexagons' fill='#b0b0b0' fill-opacity='0.4' fill-rule='nonzero'><path d='M13.99 9.25l13 7.5v15l-13 7.5L1 31.75v-15l12.99-7.5zM3 17.9v12.7l10.99 6.34 11-6.35V17.9l-11-6.34L3 17.9zM0 15l12.98-7.5V0h-2v6.35L0 12.69v2.3zm0 18.5L12.98 41v8h-2v-6.85L0 35.81v-2.3zM15 0v7.5L27.99 15H28v-2.31h-.01L17 6.35V0h-2zm0 49v-8l12.99-7.5H28v2.31h-.01L17 42.15V49h-2z'/></g></g></svg>"
        file = QtCore.QTemporaryFile(Form)
        if file.open():
            file.write(contents)
            file.flush()
            Form.setStyleSheet("""background-color: #000000;
                                  background-image: url(%s);""" % file.fileName())

        #Form.show()
        self.retranslateUi(Form)
        QtCore.QMetaObject.connectSlotsByName(Form)

    def retranslateUi(self, Form):
        Form.setWindowTitle(QtWidgets.QApplication.translate("Form", "Form", None, -1))
        self.Start_Stop_button.setText(QtWidgets.QApplication.translate("Form", "Start", None, -1))

class Widget(QtWidgets.QWidget, Ui_Form):
    def __init__(self, parent=None):
        super(Widget, self).__init__(parent)
        self.setupUi(self)

    def paintEvent(self, event):
        opt = QtWidgets.QStyleOption()
        opt.init(self)
        painter = QtGui.QPainter(self)
        self.style().drawPrimitive(QtWidgets.QStyle.PE_Widget, opt, painter, self)

if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv)
    w = Widget()
    w.show()
    sys.exit(app.exec_())

Answer 1

QSS不支持这种类型的url，一种解决方法是将内容保存在一个临时文件中，该文件在关闭应用程序时会被删除，为此，我们使用QTemporaryFile。

另一方面，URL具有以下格式：data:image/svg+xml,<CONTENT>，即您应使用的内容。

from PyQt5 import QtCore, QtGui, QtWidgets

class Ui_Form(object):
    def setupUi(self, Form):
        Form.setObjectName("Form")
        Form.resize(400, 300)
        self.horizontalLayout_2 = QtWidgets.QHBoxLayout(Form)
        self.horizontalLayout_2.setObjectName("horizontalLayout_2")
        self.horizontalLayout = QtWidgets.QHBoxLayout()
        self.horizontalLayout.setObjectName("horizontalLayout")
        self.horizontalLayout_2.addLayout(self.horizontalLayout)
        self.retranslateUi(Form)

        contents = b"<svg xmlns='http://www.w3.org/2000/svg' width='28' height='49' viewBox='0 0 28 49'><g fill-rule='evenodd'><g id='hexagons' fill='#b0b0b0' fill-opacity='0.4' fill-rule='nonzero'><path d='M13.99 9.25l13 7.5v15l-13 7.5L1 31.75v-15l12.99-7.5zM3 17.9v12.7l10.99 6.34 11-6.35V17.9l-11-6.34L3 17.9zM0 15l12.98-7.5V0h-2v6.35L0 12.69v2.3zm0 18.5L12.98 41v8h-2v-6.85L0 35.81v-2.3zM15 0v7.5L27.99 15H28v-2.31h-.01L17 6.35V0h-2zm0 49v-8l12.99-7.5H28v2.31h-.01L17 42.15V49h-2z'/></g></g></svg>"
        file = QtCore.QTemporaryFile(Form)
        if file.open():
            file.write(contents)
            file.flush()
            Form.setStyleSheet("""background-color: #000000;
                                  background-image: url(%s);""" % file.fileName())
        QtCore.QMetaObject.connectSlotsByName(Form)

    def retranslateUi(self, Form):
        Form.setWindowTitle(QtWidgets.QApplication.translate("Form", "Form", None, -1))


if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv)
    Form = QtWidgets.QWidget()
    ui = Ui_Form()
    ui.setupUi(Form)
    Form.show()
    sys.exit(app.exec_())

---

似乎PySide2有点特殊，它看起来更像Qt，因为此问题在C ++中正在等待，而在Python中却没有。对于支持QSS的窗口小部件，应使用paintEvent实现QStyle，但是为此，我们必须创建类窗口小部件，因为类Ui_Form不是窗口小部件，它只是一个窗口小部件。用于填充小部件的类。下面我显示了可行的代码。

from PySide2 import QtCore, QtGui, QtWidgets

class Ui_Form(object):
    def setupUi(self, Form):
        Form.setObjectName("Form")
        Form.resize(400, 300)
        self.horizontalLayout_2 = QtWidgets.QHBoxLayout(Form)
        self.horizontalLayout_2.setObjectName("horizontalLayout_2")
        self.horizontalLayout = QtWidgets.QHBoxLayout()
        self.horizontalLayout.setObjectName("horizontalLayout")
        self.horizontalLayout_2.addLayout(self.horizontalLayout)
        self.retranslateUi(Form)

        contents = b"<svg xmlns='http://www.w3.org/2000/svg' width='28' height='49' viewBox='0 0 28 49'><g fill-rule='evenodd'><g id='hexagons' fill='#b0b0b0' fill-opacity='0.4' fill-rule='nonzero'><path d='M13.99 9.25l13 7.5v15l-13 7.5L1 31.75v-15l12.99-7.5zM3 17.9v12.7l10.99 6.34 11-6.35V17.9l-11-6.34L3 17.9zM0 15l12.98-7.5V0h-2v6.35L0 12.69v2.3zm0 18.5L12.98 41v8h-2v-6.85L0 35.81v-2.3zM15 0v7.5L27.99 15H28v-2.31h-.01L17 6.35V0h-2zm0 49v-8l12.99-7.5H28v2.31h-.01L17 42.15V49h-2z'/></g></g></svg>"
        file = QtCore.QTemporaryFile(Form)
        if file.open():
            file.write(contents)
            file.flush()
            Form.setStyleSheet("""background-color: #000000;
                                  background-image: url(%s);""" % file.fileName())

        QtCore.QMetaObject.connectSlotsByName(Form)

    def retranslateUi(self, Form):
        Form.setWindowTitle(QtWidgets.QApplication.translate("Form", "Form", None, -1))


class Widget(QtWidgets.QWidget, Ui_Form):
    def __init__(self, parent=None):
        super(Widget, self).__init__(parent)
        self.setupUi(self)

    def paintEvent(self, event):
        opt = QtWidgets.QStyleOption()
        opt.init(self)
        painter = QtGui.QPainter(self)
        self.style().drawPrimitive(QtWidgets.QStyle.PE_Widget, opt, painter, self)

if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv)
    w = Widget()
    w.show()
    sys.exit(app.exec_())

---

加号：

QSS具有应用以下链接中指示的样式的规则：

• https://doc.qt.io/Qt-5/stylesheet-syntax.html
• http://doc.qt.io/qt-5/stylesheet-reference.html

在这种情况下，它仅适用于当前窗口小部件，因此必须使用objectName：

Form.setStyleSheet("""QWidget#Form{background-color: #000000;
                      background-image: url(%s);}""" % file.fileName())