PyQt5从输入值自动绘图

Question

我最近用Qpaint创建了一个小部件，我想向它传递值，同时强制Qpaint小部件从输入值中提取。其思想是从Qdialog定义一个数据值并将其传递给主小部件，然后将该值传递给Qpaint Widget class。我希望，当用户单击“获取值”按钮时，会出现一个对话框小部件，并插入一些int值，然后将其传递给主窗口小部件。从那里传递值以更正class Paint。它将绘制并显示结果。我尝试使用Qlabel，先给Qlabel or QlineEdit赋值

class Button(QtWidgets.QWidget):
    def __init__(self, parent=None):
        super(Button, self).__init__(parent)
          ---------

        self.value = QtWidgets.QLabel()

           --------

然后在paint class中调用这些值或文本。然后将其分配给Qpaint event。但似乎不起作用

^{pr2}$

代码主.py

import sys
from PyQt5 import QtCore, QtGui, QtWidgets
from datainput import *


class Foo(QtWidgets.QWidget):
    def __init__(self, parent=None):
        super(Foo, self).__init__(parent)
        self.setGeometry(QtCore.QRect(200, 100, 800, 800))

        self.button = Button()
        self.paint = Paint()

        self.lay = QtWidgets.QVBoxLayout()
        self.lay.addWidget(self.paint)
        self.lay.addWidget(self.button)
        self.setLayout(self.lay)

class Paint(QtWidgets.QWidget):
    def __init__(self, parent=None):
        super(Paint, self).__init__(parent)

        self.button = Button()
        self.Value = self.button.value

        self.setBackgroundRole(QtGui.QPalette.Base)       
        self.setAutoFillBackground(True)

    def paintEvent(self, event):

        self.pen = QtGui.QPen()
        self.brush = QtGui.QBrush( QtCore.Qt.gray, QtCore.Qt.Dense7Pattern)
        painter = QtGui.QPainter(self)
        painter.setRenderHint(QtGui.QPainter.Antialiasing)
        painter.setPen(self.pen)
        painter.setBrush(self.brush)
        painter.drawRect(100,100,250,250)
        painter.setBrush(QtGui.QBrush())

class Button(QtWidgets.QWidget):
    def __init__(self, parent=None):
        super(Button, self).__init__(parent)

        getbutton = QtWidgets.QPushButton('Getting values')
        Alay = QtWidgets.QVBoxLayout(self)
        Alay.addWidget(getbutton)

        self.value = QtWidgets.QLabel()

        getbutton.clicked.connect(self.getbuttonfunc)


    def getbuttonfunc(self):
        subwindow=Dinput()
        subwindow.setWindowModality(QtCore.Qt.ApplicationModal)
        if subwindow.exec_() == QtWidgets.QDialog.Accepted:
            self._output = subwindow.valueEdit.text()
            return self.value.setText(self._output)


if __name__ == '__main__':
    app = QtWidgets.QApplication(sys.argv)
    w = Foo()
    w.show()
    sys.exit(app.exec_())

输入Qdialog代码，数据输入.py

import sys
from PyQt5 import QtCore, QtGui, QtWidgets

class Dinput(QtWidgets.QDialog):
    def __init__(self, parent=None):
        super(Dinput, self).__init__(parent)

        valuelabel = QtWidgets.QLabel('Input: ')
        self.valueEdit = QtWidgets.QLineEdit()

        buttonBox = QtWidgets.QDialogButtonBox()
        buttonBox.setStandardButtons(QtWidgets.QDialogButtonBox.Cancel|QtWidgets.QDialogButtonBox.Ok)
        buttonBox.accepted.connect(self.accept) 
        buttonBox.rejected.connect(self.close)

        self.Alay = QtWidgets.QHBoxLayout()
        self.Alay.addWidget(valuelabel)
        self.Alay.addWidget(self.valueEdit)

        self.Blay = QtWidgets.QVBoxLayout()
        self.Blay.addLayout(self.Alay)
        self.Blay.addWidget(buttonBox)
        self.setLayout(self.Blay)

    def closeEvent(self, event):
        super(Dinput, self).closeEvent(event)

    def accept(self):          
        super(Dinput, self).accept()

if __name__ == '__main__':
    app = QtWidgets.QApplication(sys.argv)
    w = Dinput()
    w.show()
    sys.exit(app.exec_())

可视化

谢谢你的帮助。感谢

Answer 1

datainput是无关的，你的任务只是获得一个数字，所以对于空间问题我不会使用它，而是使用QInputDialog::getInt()。关于这个问题，在这些情况下，可以在任何时候获得值的策略是通过一个信号通知另一个视图的更改，在接收值的插槽中更新一个存储该值的变量并调用update，以便在必要时调用paintEvent，在paintEvent中使用存储价值观。在

import sys
from PyQt5 import QtCore, QtGui, QtWidgets


class Foo(QtWidgets.QWidget):
    def __init__(self, parent=None):
        super(Foo, self).__init__(parent)
        self.setGeometry(QtCore.QRect(200, 100, 800, 800))

        self.button = Button()
        self.paint = Paint()
        self.button.valueChanged.connect(self.paint.set_size_square)

        self.lay = QtWidgets.QVBoxLayout(self)
        self.lay.addWidget(self.paint)
        self.lay.addWidget(self.button)

class Paint(QtWidgets.QWidget):
    def __init__(self, parent=None):
        super(Paint, self).__init__(parent)
        self.setBackgroundRole(QtGui.QPalette.Base)     
        self.setAutoFillBackground(True)
        self._size_square = 250

    @QtCore.pyqtSlot(int)
    def set_size_square(self, v):
        self._size_square = v
        self.update()

    def paintEvent(self, event):
        pen = QtGui.QPen()
        brush = QtGui.QBrush( QtCore.Qt.gray, QtCore.Qt.Dense7Pattern)
        painter = QtGui.QPainter(self)
        painter.setRenderHint(QtGui.QPainter.Antialiasing)
        painter.setPen(pen)
        painter.setBrush(brush)
        r = QtCore.QRect(QtCore.QPoint(100, 100), self._size_square*QtCore.QSize(1, 1))
        painter.drawRect(r)

class Button(QtWidgets.QWidget):
    valueChanged = QtCore.pyqtSignal(int)

    def __init__(self, parent=None):
        super(Button, self).__init__(parent)
        getbutton = QtWidgets.QPushButton('Getting values')
        Alay = QtWidgets.QVBoxLayout(self)
        Alay.addWidget(getbutton)
        self.value = QtWidgets.QLabel()
        getbutton.clicked.connect(self.getbuttonfunc)

    @QtCore.pyqtSlot()
    def getbuttonfunc(self):
        number, ok = QtWidgets.QInputDialog.getInt(self, self.tr("Set Number"),
                                         self.tr("Input:"), 1, 1)
        if ok:
            self.valueChanged.emit(number)

if __name__ == '__main__':
    app = QtWidgets.QApplication(sys.argv)
    w = Foo()
    w.show()
    sys.exit(app.exec_())