PyQt5从输入值自动绘图

Question

我最近创建了一个带有Qpaint 的小部件，我想将值传递给它，同时强制Qpaint 小部件从输入值中提取。这个想法是从Qdialog 定义一个数据值并将其传递给主小部件，然后将值传递给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，然后将其传递给主小部件。从那里传递值以纠正class Paint。这将绘制并显示结果。我尝试使用Qlabel，首先将值分配给Qlabel or QlineEdit，

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

        self.value = QtWidgets.QLabel()

           --------

然后在paint class 里面调用那些值或者文本。然后将其分配给Qpaint event。但似乎不起作用。'

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

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

          ---------

        painter.drawRect(100,100,250,250)     <----- instead of value 250 having self.Value

代码 Main.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，datainput.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

感谢您的帮助。谢谢sss

Answer 1

datainput 无关紧要，你的任务只是获取一个数字，所以对于空格问题我不会使用它，而是使用QInputDialog::getInt()。直奔问题，在这些随时可以获取值的情况下，策略是通过一个信号通知另一个视图的变化，在接收到值的槽中是更新一个存储值的变量并调用更新以便它在必要时调用paintEvent，并在paintEvent 中使用存储值的变量。

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_())