python - pyqt 在现有的 GUI 小部件上绘图

Question

我是 pyqt 的新手。我正在做一个程序，它允许你点击图片并记住你点击的点的坐标，并在 GUI 的小部件上画一个火柴人。我的代码现在可以弹出一个新窗口来显示一个有 4 个点的多边形。但是，我希望它可以显示在我已经用pyqt制作的ui文件上。小部件的对象名称称为小部件。我希望有人可以帮助我修改代码以在 gui 小部件上显示多边形而不提示新窗口。

非常感谢!!!

import sys
from PyQt4.QtCore import *
from PyQt4 import QtGui, QtCore
from PyQt4.QtGui import *
from Main_window import *

global imgloc
imgloc = "1.jpg"
array = []
clicks = 0

class MyForm(QtGui.QMainWindow):

    def __init__(self, parent=None):
        QtGui.QWidget.__init__(self, parent)
        self.ui = Ui_MainWindow()
        self.ui.setupUi(self)
        self.local_image = QImage(imgloc)
        self.imageLocation = imgloc
        self.local_scene = QGraphicsScene()
        self.pixMapItem = QGraphicsPixmapItem(QPixmap(self.local_image), None, self.local_scene)
        self.ui.graphicsView_5.setScene( self.local_scene )
        self.pixMapItem.mousePressEvent = self.pixelSelect

    def pixelSelect(self,event):
        global imgloc
        a = event.pos().x()
        b = event.pos().y()
        global clicks
        global array
        if clicks != 4:
            clicks += 1
            point = QPoint(a,b)
            array.append(point)
        else:
            clicks = 0
            dialog = DialogBody()
            dialog.show()
            dialog.exec_()
            array = []

class DialogBody(QDialog):
    def __init__(self,parent=None):
        super(QDialog,self).__init__(parent)
        self.setGeometry(100, 100, QImage(imgloc).height(), QImage(imgloc).width())

    def paintEvent(self,e):
        qp = QtGui.QPainter()
        qp.begin(self)
        self.drawBody(qp)
        qp.end()

    def drawBody(self, qp):
        qp.setPen(QtCore.Qt.red)
        qp.drawPolygon(array[0],array[1],array[2],array[3])
        qp.drawEllipse(array[0],2,2)
        qp.drawEllipse(array[1],2,2)
        qp.drawEllipse(array[2],2,2)
        qp.drawEllipse(array[3],2,2)

if __name__ == "__main__":
   app = QtGui.QApplication(sys.argv)
   myapp= MyForm()
   myapp.show()
   sys.exit(app.exec_())

Answer 1

看起来你想在 QGraphicsScene 上绘制项目？在这种情况下，您可以将项目添加到场景中:

#!/usr/bin/env python
import sys

from PyQt4 import QtCore, QtGui


class MainWidget(QtGui.QWidget):
    def __init__(self, parent=None):
        QtGui.QWidget.__init__(self, parent)
        self.scene = QtGui.QGraphicsScene()
        self.view = QtGui.QGraphicsView(self.scene)
        layout = QtGui.QVBoxLayout()
        layout.addWidget(self.view)
        self.setLayout(layout)
        self.pixmap_item = QtGui.QGraphicsPixmapItem(QtGui.QPixmap('image.png'), None, self.scene)
        self.pixmap_item.mousePressEvent = self.pixelSelect
        self.click_positions = []

    def pixelSelect(self, event):
        self.click_positions.append(event.pos())
        if len(self.click_positions) < 4:
            return
        pen = QtGui.QPen(QtCore.Qt.red)
        self.scene.addPolygon(QtGui.QPolygonF(self.click_positions), pen)
        for point in self.click_positions:
            self.scene.addEllipse(point.x(), point.y(), 2, 2, pen)
        self.click_positions = []


if __name__ == "__main__":
    app = QtGui.QApplication(sys.argv)
    widget = MainWidget()
    widget.resize(640, 480)
    widget.show()
    sys.exit(app.exec_())

QGraphicsScene有很多特点。

阅读Graphics View Framework overview在 Qt 文档中。