如何在现有的 QGraphicsVIew 中绘图？

Question

就像标题所说的那样，我正在尝试在现有的 QGraphicsView 中绘制。我使用 QT Designer 生成的 window，我想在 QGraphicsView 中绘制一个 16x16 正方形的矩阵。

这是我目前拥有的代码：

Window:

# -*- coding: utf-8 -*-
# Form implementation generated from reading ui file 'untitled.ui'
#
# Created by: PyQt5 UI code generator 5.8.2
#
# WARNING! All changes made in this file will be lost!

from PyQt5 import QtCore, QtGui, QtWidgets

class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(911, 567)
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.label = QtWidgets.QLabel(self.centralwidget)
        self.label.setGeometry(QtCore.QRect(20, 10, 301, 31))
        font = QtGui.QFont()
        font.setPointSize(12)
        font.setBold(True)
        font.setWeight(75)
        self.label.setFont(font)
        self.label.setObjectName("label")
        self.groupBox = QtWidgets.QGroupBox(self.centralwidget)
        self.groupBox.setGeometry(QtCore.QRect(620, 40, 271, 91))
        font = QtGui.QFont()
        font.setBold(True)
        font.setWeight(75)
        self.groupBox.setFont(font)
        self.groupBox.setObjectName("groupBox")
        self.rdtest = QtWidgets.QRadioButton(self.groupBox)
        self.rdtest.setGeometry(QtCore.QRect(60, 60, 101, 22))
        self.rdtest.setObjectName("rdtest")
        self.rdtrain = QtWidgets.QRadioButton(self.groupBox)
        self.rdtrain.setGeometry(QtCore.QRect(60, 30, 101, 22))
        self.rdtrain.setObjectName("rdtrain")
        self.graphicsView = QtWidgets.QGraphicsView(self.centralwidget)
        self.graphicsView.setGeometry(QtCore.QRect(10, 40, 601, 411))
        self.graphicsView.setObjectName("graphicsView")
        self.clear = QtWidgets.QPushButton(self.centralwidget)
        self.clear.setGeometry(QtCore.QRect(10, 470, 88, 29))
        self.clear.setObjectName("clear")
        self.trainNewInput = QtWidgets.QPushButton(self.centralwidget)
        self.trainNewInput.setGeometry(QtCore.QRect(500, 470, 111, 29))
        self.trainNewInput.setObjectName("trainNewInput")
        self.trainbox = QtWidgets.QGroupBox(self.centralwidget)
        self.trainbox.setGeometry(QtCore.QRect(620, 150, 271, 171))
        font = QtGui.QFont()
        font.setBold(True)
        font.setWeight(75)
        self.trainbox.setFont(font)
        self.trainbox.setObjectName("trainbox")
        self.vtrain = QtWidgets.QLineEdit(self.trainbox)
        self.vtrain.setGeometry(QtCore.QRect(100, 70, 101, 29))
        self.vtrain.setObjectName("vtrain")
        self.label_2 = QtWidgets.QLabel(self.trainbox)
        self.label_2.setGeometry(QtCore.QRect(40, 70, 56, 31))
        font = QtGui.QFont()
        font.setBold(True)
        font.setWeight(75)
        self.label_2.setFont(font)
        self.label_2.setObjectName("label_2")
        self.trainDefault = QtWidgets.QPushButton(self.trainbox)
        self.trainDefault.setGeometry(QtCore.QRect(40, 30, 161, 29))
        self.trainDefault.setObjectName("trainDefault")
        self.output = QtWidgets.QLabel(self.trainbox)
        self.output.setGeometry(QtCore.QRect(10, 130, 271, 17))
        self.output.setText("")
        self.output.setObjectName("output")
        self.output_2 = QtWidgets.QLabel(self.trainbox)
        self.output_2.setGeometry(QtCore.QRect(10, 150, 271, 17))
        self.output_2.setText("")
        self.output_2.setObjectName("output_2")
        self.testbox = QtWidgets.QGroupBox(self.centralwidget)
        self.testbox.setGeometry(QtCore.QRect(620, 330, 271, 171))
        font = QtGui.QFont()
        font.setBold(True)
        font.setWeight(75)
        self.testbox.setFont(font)
        self.testbox.setObjectName("testbox")
        self.pushButton = QtWidgets.QPushButton(self.testbox)
        self.pushButton.setGeometry(QtCore.QRect(50, 40, 161, 29))
        self.pushButton.setObjectName("pushButton")
        MainWindow.setCentralWidget(self.centralwidget)
        self.menubar = QtWidgets.QMenuBar(MainWindow)
        self.menubar.setGeometry(QtCore.QRect(0, 0, 911, 23))
        self.menubar.setObjectName("menubar")
        MainWindow.setMenuBar(self.menubar)
        self.statusbar = QtWidgets.QStatusBar(MainWindow)
        self.statusbar.setObjectName("statusbar")
        MainWindow.setStatusBar(self.statusbar)

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

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
        self.label.setText(_translate("MainWindow", "RNA: Numeros "))
        self.groupBox.setTitle(_translate("MainWindow", "Opciones:"))
        self.rdtest.setText(_translate("MainWindow", "Test"))
        self.rdtrain.setText(_translate("MainWindow", "Train"))
        self.clear.setText(_translate("MainWindow", "Clear"))
        self.trainNewInput.setText(_translate("MainWindow", "Train new Input"))
        self.trainbox.setTitle(_translate("MainWindow", "Train:"))
        self.label_2.setText(_translate("MainWindow", "% Test:"))
        self.trainDefault.setText(_translate("MainWindow", "Train Default Data"))
        self.testbox.setTitle(_translate("MainWindow", "Test:"))
        self.pushButton.setText(_translate("MainWindow", "Start Test"))


if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv)
    MainWindow = QtWidgets.QMainWindow()
    ui = Ui_MainWindow()
    ui.setupUi(MainWindow)
    MainWindow.show()
    sys.exit(app.exec_())

Logic class 我想创建一个从 window:

中绘制 QGraphicsView 的方法

import sys
from PyQt5 import QtCore, QtGui, QtWidgets
from PyQt5.QtWidgets import QGraphicsScene
from PyQt5.QtCore import (QLineF, QPointF, QRectF, Qt)
from PyQt5.QtWidgets import QWidget, QApplication
from PyQt5.QtWidgets import (QApplication, QGraphicsView, QGraphicsScene, QGraphicsItem,
                             QGridLayout, QVBoxLayout, QHBoxLayout,
                             QLabel, QLineEdit, QPushButton)
from window import Ui_MainWindow
from RNA import NumberIA

train = []
train_r = []
test = []
test_r = []


class MyFirstGuiProgram(Ui_MainWindow):
    def __init__(self, dialog):
        Ui_MainWindow.__init__(self)

        self.setupUi(dialog)
        self.rdtrain.setChecked(True)

        # Connect "add" button with a custom function (addInputTextToListbox)
        self.clear.clicked.connect(self.addInputTextToListbox)
        self.trainDefault.clicked.connect(self.t_DefaultData)
        self.rdtest.clicked.connect(self.enableTest)
        self.rdtrain.clicked.connect(self.enableTrain)

    def enableTest(self):
        self.trainbox.setEnabled(False)
        self.trainNewInput.setEnabled(False)
        self.testbox.setEnabled(True)

    def drawSomething(self):
        tes = "f"

    def enableTrain(self):
        self.trainbox.setEnabled(True)
        self.trainNewInput.setEnabled(True)
        self.testbox.setEnabled(False)

    def addInputTextToListbox(self):
        print("Hello world!!!")

    def t_DefaultData(self):
        ann = NumberIA()

        t = self.vtrain.text()
        print("Training data: ", t)

        global train
        global train_r
        global test
        global test_r
        train, train_r, test, test_r = ann.read_file(float(t))
        self.output.setText("Train complete...")

        ann.crear_red(train, train_r)
        accuracy, matrix = ann.probar_red(test, test_r)
        self.output_2.setText("Accuracy: " + str(accuracy * 100) + "%")

        print("Matris de Confusion:")
        print('\n'.join([''.join(['{:4}'.format(item) for item in row])
                         for row in matrix]))


if __name__ == '__main__':
    app = QtWidgets.QApplication(sys.argv)
    MainWindow = QtWidgets.QMainWindow()
    ui = MyFirstGuiProgram(MainWindow)
    MainWindow.show()
    MainWindow.setWindowTitle("RNA: Inteligencia Artificial 2")
    ui.enableTrain()
    sys.exit(app.exec_())

我似乎无法在网上找到有关如何执行此操作的示例，我找到的示例对我来说很模糊，似乎无法弄清楚。

Answer 1

我建议你继承 QMainWindow 并实现 Ui_MainWindow 接口，要在 QGraphicsView 中绘制你必须使用 QGraphicsScene，并使用它的方法，在这种情况下使用 addRect().

from PyQt5 import QtCore, QtGui, QtWidgets

class MyFirstGuiProgram(QtWidgets.QMainWindow, Ui_MainWindow):
    def __init__(self, parent=None):
        QtWidgets.QMainWindow.__init__(self, parent=parent)
        self.setupUi(self)
        scene = QtWidgets.QGraphicsScene()
        self.graphicsView.setScene(scene)
        pen = QtGui.QPen(QtCore.Qt.green)

        side = 20

        for i in range(16):
            for j in range(16):
                r = QtCore.QRectF(QtCore.QPointF(i*side, j*side), QtCore.QSizeF(side, side))
                scene.addRect(r, pen)


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

Answer 2

@eyllanesc 刚刚在上面给了你很好的例子，如果你需要像简单的徒手画画一样，这是我刚好找到的另一个小例子。

拥有您的 MainWindow，例如 QMainWindow 或 Qwidget 或...
有一个 QGraphicsView。
使用 QGraphicsScene 设置 QGraphicsView 的场景
拥有自己的 QGraphicsPathItem，以便您可以设置所需的属性。
在你的场景中实现了你想要绘制的东西，所以它知道如何在自己身上绘制。

有了这样的东西，你就可以控制几个场景，知道如何独立地在自己身上画画，当然如果你需要不止一个场景。

这个例子的逻辑是在 QGraphicsView 中实现的，你可以把它移到你的 GraphicsScene 中。

class MainWindow(QMainWindow):

    central_widget = None
    layout_container = None

    def __init__(self):
        super(MainWindow, self).__init__()
        self.central_widget = QWidget()
        self.layout_container = QVBoxLayout()
        self.central_widget.setLayout(self.layout_container)
        self.setCentralWidget(self.central_widget)
        self.layout_container.addWidget(GraphicsView())

class GraphicsView(QGraphicsView):

    start = None
    end = None
    item = None
    path = None

    def __init__(self):
        super(GraphicsView, self).__init__()
        self.setScene(QGraphicsScene())
        self.path = QPainterPath()
        self.item = GraphicsPathItem()
        self.scene().addItem(self.item)

    def mousePressEvent(self, event):
        self.start = self.mapToScene(event.pos())
        self.path.moveTo(self.start)

    def mouseMoveEvent(self, event):
        self.end = self.mapToScene(event.pos())
        self.path.lineTo(self.end)
        self.start = self.end
        self.item.setPath(self.path)

class GraphicsPathItem(QGraphicsPathItem):

    def __init__(self):
        super(GraphicsPathItem, self).__init__()
        pen = QPen()
        pen.setColor(Qt.black)
        pen.setWidth(10)
        self.setPen(pen)

if __name__ == '__main__':
    app = QApplication(sys.argv)
    mw = MainWindow()
    mw.show()
    sys.exit(app.exec_())

Answer 3

你也可以通过QLineF()来绘制，它从设计的角度提供了更多的控制。

import sys
from PyQt5.QtCore import *
from PyQt5.QtGui import *
from PyQt5.QtWidgets import *

def sceneWithPen(grid):

    scene = QGraphicsScene()
    view = QGraphicsView()
    view.setScene(scene)
                                        # Creating line's colors
    red = QColor(qRgb(172, 50, 99))
    blue = QColor(qRgb(50, 150, 203))
                                        # Set length of square's side and number of horizontal and vertical lines
    vLines = 16
    hLines = 16
    side = 30
                                        # Set starting values for loops
    hor = 0
    ver = 0
    subdiv = 16
    leftX,leftY = 0, 0
    rightX, rightY = subdiv*side, 0
    bottomX, bottomY= 0, 0
    topX, topY = 0, subdiv*side

    while ver < vLines:
                                        # Drawing vertical lines
        ver = ver + 1
        vLine = QLineF(bottomX, bottomY, topX, topY)
        bottomX, topX = bottomX + side, topX + side
        scene.addLine(vLine, red)

    while hor < hLines:
                                        #Drawing horizontal lines
        hor = hor + 1
        hLine = QLineF(leftX, leftY, rightX, rightY)
        leftY, rightY = leftY + side, rightY + side
        scene.addLine(hLine, blue)

    grid.addWidget(view)

if __name__ == '__main__':
    app = QApplication(sys.argv)
    w = QWidget()
    grid = QGridLayout()
    sceneWithPen(grid)
    w.setLayout(grid)
    w.show()
    sys.exit(app.exec_())

会变成这样：

如何在现有的 QGraphicsVIew 中绘图？

How can I draw inside existing QGraphicsVIew?

python

pyqt

qt-designer

qgraphicsview

pyqt5