在图形视图上错误位置绘制的小部件之间的线答案

【问题标题】：Line between widgets drawn in wrong position on graphics view在图形视图上错误位置绘制的小部件之间的线
【发布时间】：2015-04-15 10:56:10
【问题描述】：

我正在将两个小部件（两个按钮）之间的一条线绘制到一个图形视图中，并将它们的位置作为参考。但是这条线画错了地方。

我尝试使用 mapToGlobal 或 mapToParent 之类的函数得到不同的结果，但它仍然是错误的。在同一个类中，我有另一种用鼠标画线的方法，它工作正常。我把它当作参考，但似乎事件位置具有不同的坐标系。我不知道为什么会这样。

按钮和图形视图位于 Widget 内部，Widget 也位于窗口内部。

这是类：

from PyQt4 import QtGui, QtCore

class WiringGraphicsView(QtGui.QGraphicsView):

    def __init__(self, parent):
        QtGui.QGraphicsView.__init__(self, parent)
        self.setScene(QtGui.QGraphicsScene(self))
        #self.setSceneRect(QtCore.QRectF(self.viewport().rect()))

    def mousePressEvent(self, event):
        self._start = event.pos()

    def mouseReleaseEvent(self, event):
        start = QtCore.QPointF(self.mapToScene(self._start))
        end = QtCore.QPointF(self.mapToScene(event.pos()))
        brush = QtGui.QBrush(QtGui.QColor(255, 0, 0) )
        pen = QtGui.QPen(brush, 2)
        line = QtGui.QGraphicsLineItem(QtCore.QLineF(start, end))
        line.setPen(pen)
        self.scene().addItem( line )

    def paintWire(self, start_widget,  end_widget):
        start_position = QtCore.QPointF(self.mapToScene(start_widget.pos()))
        end_position = QtCore.QPointF(self.mapToScene(end_widget.pos()))
        brush = QtGui.QBrush(QtGui.QColor(255, 0, 0) )
        pen = QtGui.QPen(brush, 2)
        line = QtGui.QGraphicsLineItem(QtCore.QLineF(start_position, end_position))
        line.setPen(pen)
        self.scene().addItem( line )

更新：此时我已经尝试了几件事：由于按钮包含在 QWidget 对象中，因此我将它们从那里取出。我将它们放在 GroupBox 中。也试过没有容器。我没有得到满意的结果。老实说，考虑到我正在使用 Qt 设计器并为“升级”小部件（在本例中是 GraphicsView）创建类文件并使用 UpdateUi 方法设置一些属性，我不知道如何正确执行此操作文件

更新 2：这是加载应用程序的文件：

from PyQt4.QtCore import *
from PyQt4.QtGui import *
import ui_wolfsonmixerwindow

class WolfsonMixerWindow(QMainWindow, ui_wolfsonmixerwindow.Ui_WolfsonMixerWindow):

      def __init__(self,  parent=None):
         super(WolfsonMixerWindow,  self).__init__(parent)
         self.setupUi(self)
         self.updateUi()


      def updateUi(self):
          #self.btn_AIF1RX1.setText("Hola")

          menu_plugin = QMenu()
          menu_unplug = QMenu()

          menu_plugin.addAction('Action 1', self.plugin )
          self.btn_AIF1RX1_2.setMenu(menu_plugin)

          self.btn_AIF1TX1_5.setAllowDrag(False)
          self.btn_AIF1TX1_5.setMenu(menu_unplug)



          start = self.btn_AIF1RX1_2
          end = self.btn_AIF1TX1_5

          #self.graphicsView.scene().addWidget(self.btn_AIF1RX1_2)
          #self.graphicsView.scene().addWidget(self.btn_AIF1TX1_5)
          #self.graphicsView.setWidgets(start, end)

           #HERE I CALL THE PAINTWIRE METHOD
          self.graphicsView.paintWire(start, end)


if __name__ == "__main__":
  import sys
  app = QApplication(sys.argv)
  form = WolfsonMixerWindow()
  form.show()
  app.exec_()

还有uic文件：

# -*- coding: utf-8 -*-

# Form implementation generated from reading ui file 'ui_wolfsonmixerwindow.ui'
#
# Created: Thu Feb 19 21:51:35 2015
#      by: PyQt4 UI code generator 4.11.3
#
# WARNING! All changes made in this file will be lost!

from PyQt4 import QtCore, QtGui

try:
    _fromUtf8 = QtCore.QString.fromUtf8
except AttributeError:
    def _fromUtf8(s):
        return s

try:
    _encoding = QtGui.QApplication.UnicodeUTF8
    def _translate(context, text, disambig):
        return QtGui.QApplication.translate(context, text, disambig, _encoding)
except AttributeError:
    def _translate(context, text, disambig):
        return QtGui.QApplication.translate(context, text, disambig)

class Ui_WolfsonMixerWindow(object):
    def setupUi(self, WolfsonMixerWindow):
        WolfsonMixerWindow.setObjectName(_fromUtf8("WolfsonMixerWindow"))
        WolfsonMixerWindow.resize(562, 480)
        self.centralwidget = QtGui.QWidget(WolfsonMixerWindow)
        self.centralwidget.setObjectName(_fromUtf8("centralwidget"))
        self.gridLayoutWidget = QtGui.QWidget(self.centralwidget)
        self.gridLayoutWidget.setGeometry(QtCore.QRect(200, 10, 241, 101))
        self.gridLayoutWidget.setLocale(QtCore.QLocale(QtCore.QLocale.English, QtCore.QLocale.UnitedStates))
        self.gridLayoutWidget.setObjectName(_fromUtf8("gridLayoutWidget"))
        self.gridLayout = QtGui.QGridLayout(self.gridLayoutWidget)
        self.gridLayout.setSizeConstraint(QtGui.QLayout.SetMaximumSize)
        self.gridLayout.setMargin(0)
        self.gridLayout.setObjectName(_fromUtf8("gridLayout"))
        self.QHBox_Playback = QtGui.QHBoxLayout()
        self.QHBox_Playback.setObjectName(_fromUtf8("QHBox_Playback"))
        self.verticalLayout = QtGui.QVBoxLayout()
        self.verticalLayout.setObjectName(_fromUtf8("verticalLayout"))
        self.label_2 = QtGui.QLabel(self.gridLayoutWidget)
        self.label_2.setLocale(QtCore.QLocale(QtCore.QLocale.English, QtCore.QLocale.UnitedStates))
        self.label_2.setAlignment(QtCore.Qt.AlignCenter)
        self.label_2.setObjectName(_fromUtf8("label_2"))
        self.verticalLayout.addWidget(self.label_2)
        self.label = QtGui.QLabel(self.gridLayoutWidget)
        self.label.setLocale(QtCore.QLocale(QtCore.QLocale.English, QtCore.QLocale.UnitedStates))
        self.label.setAlignment(QtCore.Qt.AlignCenter)
        self.label.setObjectName(_fromUtf8("label"))
        self.verticalLayout.addWidget(self.label)
        self.btn_AIF1RX1 = DragButton(self.gridLayoutWidget)
        self.btn_AIF1RX1.setBaseSize(QtCore.QSize(0, 0))
        self.btn_AIF1RX1.setMouseTracking(True)
        self.btn_AIF1RX1.setLocale(QtCore.QLocale(QtCore.QLocale.English, QtCore.QLocale.UnitedStates))
        self.btn_AIF1RX1.setText(_fromUtf8(""))
        icon = QtGui.QIcon()
        icon.addPixmap(QtGui.QPixmap(_fromUtf8(":/audio-input-line.png")), QtGui.QIcon.Normal, QtGui.QIcon.Off)
        self.btn_AIF1RX1.setIcon(icon)
        self.btn_AIF1RX1.setAutoDefault(False)
        self.btn_AIF1RX1.setDefault(False)
        self.btn_AIF1RX1.setFlat(True)
        self.btn_AIF1RX1.setObjectName(_fromUtf8("btn_AIF1RX1"))
        self.verticalLayout.addWidget(self.btn_AIF1RX1)
        self.QHBox_Playback.addLayout(self.verticalLayout)
        self.verticalLayout_2 = QtGui.QVBoxLayout()
        self.verticalLayout_2.setObjectName(_fromUtf8("verticalLayout_2"))
        self.label_3 = QtGui.QLabel(self.gridLayoutWidget)
        self.label_3.setLocale(QtCore.QLocale(QtCore.QLocale.English, QtCore.QLocale.UnitedStates))
        self.label_3.setAlignment(QtCore.Qt.AlignCenter)
        self.label_3.setObjectName(_fromUtf8("label_3"))
        self.verticalLayout_2.addWidget(self.label_3)
        self.label_4 = QtGui.QLabel(self.gridLayoutWidget)
        self.label_4.setLocale(QtCore.QLocale(QtCore.QLocale.English, QtCore.QLocale.UnitedStates))
        self.label_4.setAlignment(QtCore.Qt.AlignCenter)
        self.label_4.setObjectName(_fromUtf8("label_4"))
        self.verticalLayout_2.addWidget(self.label_4)
        self.btn_AIF1RX2 = QtGui.QPushButton(self.gridLayoutWidget)
        self.btn_AIF1RX2.setBaseSize(QtCore.QSize(0, 0))
        self.btn_AIF1RX2.setMouseTracking(True)
        self.btn_AIF1RX2.setLocale(QtCore.QLocale(QtCore.QLocale.English, QtCore.QLocale.UnitedStates))
        self.btn_AIF1RX2.setText(_fromUtf8(""))
        self.btn_AIF1RX2.setIcon(icon)
        self.btn_AIF1RX2.setAutoDefault(False)
        self.btn_AIF1RX2.setDefault(False)
        self.btn_AIF1RX2.setFlat(True)
        self.btn_AIF1RX2.setObjectName(_fromUtf8("btn_AIF1RX2"))
        self.verticalLayout_2.addWidget(self.btn_AIF1RX2)
        self.QHBox_Playback.addLayout(self.verticalLayout_2)
        self.gridLayout.addLayout(self.QHBox_Playback, 1, 0, 1, 1)
        self.horizontalLayout_3 = QtGui.QHBoxLayout()
        self.horizontalLayout_3.setSizeConstraint(QtGui.QLayout.SetDefaultConstraint)
        self.horizontalLayout_3.setContentsMargins(-1, -1, 0, -1)
        self.horizontalLayout_3.setObjectName(_fromUtf8("horizontalLayout_3"))
        self.verticalLayout_3 = QtGui.QVBoxLayout()
        self.verticalLayout_3.setObjectName(_fromUtf8("verticalLayout_3"))
        self.label_6 = QtGui.QLabel(self.gridLayoutWidget)
        self.label_6.setLocale(QtCore.QLocale(QtCore.QLocale.English, QtCore.QLocale.UnitedStates))
        self.label_6.setAlignment(QtCore.Qt.AlignCenter)
        self.label_6.setObjectName(_fromUtf8("label_6"))
        self.verticalLayout_3.addWidget(self.label_6)
        self.label_5 = QtGui.QLabel(self.gridLayoutWidget)
        self.label_5.setLocale(QtCore.QLocale(QtCore.QLocale.English, QtCore.QLocale.UnitedStates))
        self.label_5.setAlignment(QtCore.Qt.AlignCenter)
        self.label_5.setObjectName(_fromUtf8("label_5"))
        self.verticalLayout_3.addWidget(self.label_5)
        self.horizontalLayout = QtGui.QHBoxLayout()
        self.horizontalLayout.setSpacing(0)
        self.horizontalLayout.setSizeConstraint(QtGui.QLayout.SetDefaultConstraint)
        self.horizontalLayout.setObjectName(_fromUtf8("horizontalLayout"))
        self.btn_AIF1TX1_1 = QtGui.QPushButton(self.gridLayoutWidget)
        self.btn_AIF1TX1_1.setMouseTracking(False)
        self.btn_AIF1TX1_1.setFocusPolicy(QtCore.Qt.StrongFocus)
        self.btn_AIF1TX1_1.setAcceptDrops(True)
        self.btn_AIF1TX1_1.setLocale(QtCore.QLocale(QtCore.QLocale.English, QtCore.QLocale.UnitedStates))
        self.btn_AIF1TX1_1.setText(_fromUtf8(""))
        icon1 = QtGui.QIcon()
        icon1.addPixmap(QtGui.QPixmap(_fromUtf8(":/input_small.png")), QtGui.QIcon.Normal, QtGui.QIcon.Off)
        self.btn_AIF1TX1_1.setIcon(icon1)
        self.btn_AIF1TX1_1.setFlat(True)
        self.btn_AIF1TX1_1.setObjectName(_fromUtf8("btn_AIF1TX1_1"))
        self.horizontalLayout.addWidget(self.btn_AIF1TX1_1)
        self.btn_AIF1TX1_2 = QtGui.QPushButton(self.gridLayoutWidget)
        self.btn_AIF1TX1_2.setAcceptDrops(True)
        self.btn_AIF1TX1_2.setLocale(QtCore.QLocale(QtCore.QLocale.English, QtCore.QLocale.UnitedStates))
        self.btn_AIF1TX1_2.setText(_fromUtf8(""))
        self.btn_AIF1TX1_2.setIcon(icon1)
        self.btn_AIF1TX1_2.setFlat(True)
        self.btn_AIF1TX1_2.setObjectName(_fromUtf8("btn_AIF1TX1_2"))
        self.horizontalLayout.addWidget(self.btn_AIF1TX1_2)
        self.btn_AIF1TX1_3 = QtGui.QPushButton(self.gridLayoutWidget)
        self.btn_AIF1TX1_3.setAcceptDrops(True)
        self.btn_AIF1TX1_3.setLocale(QtCore.QLocale(QtCore.QLocale.English, QtCore.QLocale.UnitedStates))
        self.btn_AIF1TX1_3.setText(_fromUtf8(""))
        self.btn_AIF1TX1_3.setIcon(icon1)
        self.btn_AIF1TX1_3.setFlat(True)
        self.btn_AIF1TX1_3.setObjectName(_fromUtf8("btn_AIF1TX1_3"))
        self.horizontalLayout.addWidget(self.btn_AIF1TX1_3)
        self.btn_AIF1TX1_4 = QtGui.QPushButton(self.gridLayoutWidget)
        self.btn_AIF1TX1_4.setAcceptDrops(True)
        self.btn_AIF1TX1_4.setLocale(QtCore.QLocale(QtCore.QLocale.English, QtCore.QLocale.UnitedStates))
        self.btn_AIF1TX1_4.setText(_fromUtf8(""))
        self.btn_AIF1TX1_4.setIcon(icon1)
        self.btn_AIF1TX1_4.setFlat(True)
        self.btn_AIF1TX1_4.setObjectName(_fromUtf8("btn_AIF1TX1_4"))
        self.horizontalLayout.addWidget(self.btn_AIF1TX1_4)
        self.verticalLayout_3.addLayout(self.horizontalLayout)
        self.horizontalLayout_3.addLayout(self.verticalLayout_3)
        self.verticalLayout_4 = QtGui.QVBoxLayout()
        self.verticalLayout_4.setObjectName(_fromUtf8("verticalLayout_4"))
        self.label_7 = QtGui.QLabel(self.gridLayoutWidget)
        self.label_7.setLocale(QtCore.QLocale(QtCore.QLocale.English, QtCore.QLocale.UnitedStates))
        self.label_7.setAlignment(QtCore.Qt.AlignCenter)
        self.label_7.setObjectName(_fromUtf8("label_7"))
        self.verticalLayout_4.addWidget(self.label_7)
        self.label_8 = QtGui.QLabel(self.gridLayoutWidget)
        self.label_8.setLocale(QtCore.QLocale(QtCore.QLocale.English, QtCore.QLocale.UnitedStates))
        self.label_8.setAlignment(QtCore.Qt.AlignCenter)
        self.label_8.setObjectName(_fromUtf8("label_8"))
        self.verticalLayout_4.addWidget(self.label_8)
        self.horizontalLayout_2 = QtGui.QHBoxLayout()
        self.horizontalLayout_2.setSpacing(1)
        self.horizontalLayout_2.setSizeConstraint(QtGui.QLayout.SetDefaultConstraint)
        self.horizontalLayout_2.setObjectName(_fromUtf8("horizontalLayout_2"))
        self.btn_AIF1TX2_1 = QtGui.QPushButton(self.gridLayoutWidget)
        self.btn_AIF1TX2_1.setAcceptDrops(True)
        self.btn_AIF1TX2_1.setLocale(QtCore.QLocale(QtCore.QLocale.English, QtCore.QLocale.UnitedStates))
        self.btn_AIF1TX2_1.setText(_fromUtf8(""))
        self.btn_AIF1TX2_1.setIcon(icon1)
        self.btn_AIF1TX2_1.setFlat(True)
        self.btn_AIF1TX2_1.setObjectName(_fromUtf8("btn_AIF1TX2_1"))
        self.horizontalLayout_2.addWidget(self.btn_AIF1TX2_1)
        self.btn_AIF1TX2_2 = QtGui.QPushButton(self.gridLayoutWidget)
        self.btn_AIF1TX2_2.setAcceptDrops(True)
        self.btn_AIF1TX2_2.setLocale(QtCore.QLocale(QtCore.QLocale.English, QtCore.QLocale.UnitedStates))
        self.btn_AIF1TX2_2.setText(_fromUtf8(""))
        self.btn_AIF1TX2_2.setIcon(icon1)
        self.btn_AIF1TX2_2.setFlat(True)
        self.btn_AIF1TX2_2.setObjectName(_fromUtf8("btn_AIF1TX2_2"))
        self.horizontalLayout_2.addWidget(self.btn_AIF1TX2_2)
        self.btn_AIF1TX2_3 = QtGui.QPushButton(self.gridLayoutWidget)
        sizePolicy = QtGui.QSizePolicy(QtGui.QSizePolicy.Minimum, QtGui.QSizePolicy.Minimum)
        sizePolicy.setHorizontalStretch(0)
        sizePolicy.setVerticalStretch(0)
        sizePolicy.setHeightForWidth(self.btn_AIF1TX2_3.sizePolicy().hasHeightForWidth())
        self.btn_AIF1TX2_3.setSizePolicy(sizePolicy)
        self.btn_AIF1TX2_3.setAcceptDrops(True)
        self.btn_AIF1TX2_3.setLocale(QtCore.QLocale(QtCore.QLocale.English, QtCore.QLocale.UnitedStates))
        self.btn_AIF1TX2_3.setText(_fromUtf8(""))
        self.btn_AIF1TX2_3.setIcon(icon1)
        self.btn_AIF1TX2_3.setFlat(True)
        self.btn_AIF1TX2_3.setObjectName(_fromUtf8("btn_AIF1TX2_3"))
        self.horizontalLayout_2.addWidget(self.btn_AIF1TX2_3)
        self.btn_AIF1TX2_4 = QtGui.QPushButton(self.gridLayoutWidget)
        self.btn_AIF1TX2_4.setAcceptDrops(True)
        self.btn_AIF1TX2_4.setLocale(QtCore.QLocale(QtCore.QLocale.English, QtCore.QLocale.UnitedStates))
        self.btn_AIF1TX2_4.setText(_fromUtf8(""))
        self.btn_AIF1TX2_4.setIcon(icon1)
        self.btn_AIF1TX2_4.setFlat(True)
        self.btn_AIF1TX2_4.setObjectName(_fromUtf8("btn_AIF1TX2_4"))
        self.horizontalLayout_2.addWidget(self.btn_AIF1TX2_4)
        self.verticalLayout_4.addLayout(self.horizontalLayout_2)
        self.horizontalLayout_3.addLayout(self.verticalLayout_4)
        self.gridLayout.addLayout(self.horizontalLayout_3, 1, 1, 1, 1)
        self.lbl_playback = QtGui.QLabel(self.gridLayoutWidget)
        self.lbl_playback.setLocale(QtCore.QLocale(QtCore.QLocale.English, QtCore.QLocale.UnitedStates))
        self.lbl_playback.setTextFormat(QtCore.Qt.AutoText)
        self.lbl_playback.setObjectName(_fromUtf8("lbl_playback"))
        self.gridLayout.addWidget(self.lbl_playback, 0, 0, 1, 1)
        self.label_9 = QtGui.QLabel(self.gridLayoutWidget)
        self.label_9.setLocale(QtCore.QLocale(QtCore.QLocale.English, QtCore.QLocale.UnitedStates))
        self.label_9.setAlignment(QtCore.Qt.AlignCenter)
        self.label_9.setObjectName(_fromUtf8("label_9"))
        self.gridLayout.addWidget(self.label_9, 0, 1, 1, 1)
        self.dial = QtGui.QDial(self.centralwidget)
        self.dial.setGeometry(QtCore.QRect(30, 360, 50, 64))
        self.dial.setObjectName(_fromUtf8("dial"))
        self.label_10 = QtGui.QLabel(self.centralwidget)
        self.label_10.setGeometry(QtCore.QRect(20, 320, 52, 15))
        self.label_10.setObjectName(_fromUtf8("label_10"))
        self.widget = QtGui.QWidget(self.centralwidget)
        self.widget.setGeometry(QtCore.QRect(160, 400, 331, 21))
        self.widget.setObjectName(_fromUtf8("widget"))
        self.groupBox = QtGui.QGroupBox(self.centralwidget)
        self.groupBox.setGeometry(QtCore.QRect(130, 130, 361, 271))
        self.groupBox.setObjectName(_fromUtf8("groupBox"))
        self.graphicsView = WiringGraphicsView(self.groupBox)
        self.graphicsView.setGeometry(QtCore.QRect(40, 30, 291, 241))
        self.graphicsView.setVerticalScrollBarPolicy(QtCore.Qt.ScrollBarAlwaysOff)
        self.graphicsView.setHorizontalScrollBarPolicy(QtCore.Qt.ScrollBarAlwaysOff)
        brush = QtGui.QBrush(QtGui.QColor(0, 0, 0))
        brush.setStyle(QtCore.Qt.NoBrush)
        self.graphicsView.setBackgroundBrush(brush)
        self.graphicsView.setObjectName(_fromUtf8("graphicsView"))
        self.btn_AIF1RX1_2 = DragButton(self.groupBox)
        self.btn_AIF1RX1_2.setGeometry(QtCore.QRect(50, 50, 51, 31))
        self.btn_AIF1RX1_2.setBaseSize(QtCore.QSize(0, 0))
        self.btn_AIF1RX1_2.setMouseTracking(True)
        self.btn_AIF1RX1_2.setLocale(QtCore.QLocale(QtCore.QLocale.English, QtCore.QLocale.UnitedStates))
        self.btn_AIF1RX1_2.setText(_fromUtf8(""))
        self.btn_AIF1RX1_2.setIcon(icon)
        self.btn_AIF1RX1_2.setAutoDefault(False)
        self.btn_AIF1RX1_2.setDefault(False)
        self.btn_AIF1RX1_2.setFlat(True)
        self.btn_AIF1RX1_2.setObjectName(_fromUtf8("btn_AIF1RX1_2"))
        self.btn_AIF1TX1_5 = DragButton(self.groupBox)
        self.btn_AIF1TX1_5.setGeometry(QtCore.QRect(270, 150, 41, 31))
        self.btn_AIF1TX1_5.setMouseTracking(False)
        self.btn_AIF1TX1_5.setFocusPolicy(QtCore.Qt.StrongFocus)
        self.btn_AIF1TX1_5.setAcceptDrops(True)
        self.btn_AIF1TX1_5.setLocale(QtCore.QLocale(QtCore.QLocale.English, QtCore.QLocale.UnitedStates))
        self.btn_AIF1TX1_5.setText(_fromUtf8(""))
        self.btn_AIF1TX1_5.setIcon(icon1)
        self.btn_AIF1TX1_5.setFlat(True)
        self.btn_AIF1TX1_5.setObjectName(_fromUtf8("btn_AIF1TX1_5"))
        self.btn_AIF1RX1_3 = DragButton(self.groupBox)
        self.btn_AIF1RX1_3.setGeometry(QtCore.QRect(60, 110, 51, 27))
        self.btn_AIF1RX1_3.setBaseSize(QtCore.QSize(0, 0))
        self.btn_AIF1RX1_3.setMouseTracking(True)
        self.btn_AIF1RX1_3.setAcceptDrops(False)
        self.btn_AIF1RX1_3.setLocale(QtCore.QLocale(QtCore.QLocale.English, QtCore.QLocale.UnitedStates))
        self.btn_AIF1RX1_3.setText(_fromUtf8(""))
        self.btn_AIF1RX1_3.setIcon(icon)
        self.btn_AIF1RX1_3.setAutoDefault(False)
        self.btn_AIF1RX1_3.setDefault(False)
        self.btn_AIF1RX1_3.setFlat(True)
        self.btn_AIF1RX1_3.setObjectName(_fromUtf8("btn_AIF1RX1_3"))
        WolfsonMixerWindow.setCentralWidget(self.centralwidget)
        self.menubar = QtGui.QMenuBar(WolfsonMixerWindow)
        self.menubar.setGeometry(QtCore.QRect(0, 0, 562, 23))
        self.menubar.setObjectName(_fromUtf8("menubar"))
        WolfsonMixerWindow.setMenuBar(self.menubar)
        self.statusbar = QtGui.QStatusBar(WolfsonMixerWindow)
        self.statusbar.setObjectName(_fromUtf8("statusbar"))
        WolfsonMixerWindow.setStatusBar(self.statusbar)

        self.retranslateUi(WolfsonMixerWindow)
        QtCore.QObject.connect(self.dial, QtCore.SIGNAL(_fromUtf8("valueChanged(int)")), self.label_10.setNum)
        QtCore.QMetaObject.connectSlotsByName(WolfsonMixerWindow)

    def retranslateUi(self, WolfsonMixerWindow):
        WolfsonMixerWindow.setWindowTitle(_translate("WolfsonMixerWindow", "Wolfson Mixer", None))
        self.label_2.setText(_translate("WolfsonMixerWindow", "AIF1RX1", None))
        self.label.setText(_translate("WolfsonMixerWindow", "L", None))
        self.label_3.setText(_translate("WolfsonMixerWindow", "AIF1RX2", None))
        self.label_4.setText(_translate("WolfsonMixerWindow", "R", None))
        self.label_6.setText(_translate("WolfsonMixerWindow", "AIF1TX1", None))
        self.label_5.setText(_translate("WolfsonMixerWindow", "L", None))
        self.label_7.setText(_translate("WolfsonMixerWindow", "AIF1TX2", None))
        self.label_8.setText(_translate("WolfsonMixerWindow", "R", None))
        self.lbl_playback.setText(_translate("WolfsonMixerWindow", "<html><head/><body><p><span style=\" font-weight:600;\">Playback (from RPi)</span></p></body></html>", None))
        self.label_9.setText(_translate("WolfsonMixerWindow", "<html><head/><body><p><span style=\" font-weight:600;\">Record (to RPi)</span></p></body></html>", None))
        self.label_10.setText(_translate("WolfsonMixerWindow", "TextLabel", None))
        self.groupBox.setTitle(_translate("WolfsonMixerWindow", "GroupBox", None))

from wiringgraphicsview import WiringGraphicsView
from dragbutton import DragButton
import icons_rc

【问题讨论】：

您提供了错误的示例代码。用鼠标画线的类正在工作（如你所说）。但这对两个小部件之间的界限没有帮助。你能出示这段代码吗？
我不知道到底出了什么问题，因为没有图片说明这条线有多错误，也没有示例代码产生错误的线，但我发布了一个在两个小部件之间画线的工作示例图形视图作为答案。
@Trilarion 忽略鼠标事件，我使用的方法是paintWire。如您所见，它接收两个参数，start_widget 和 end_widget（临时名称），因此这些按钮将接收并在它们之间画线。
你能显示你调用paintWire的代码吗？你能显示uic 文件吗？您是否尝试过使用 pdb 进行调试？您能否在paintWire 期间围绕每个对象（用于测试目的）绘制rects，以便您可以看到边界框（以及每个对象的默认原点）？
@g19fanatic 我刚刚添加了整个 uic 文件和我调用paintWire 的主文件。我从来没有用过 pdb，但我用的是 eric6 IDE。

标签： python qt pyqt pyside qgraphicsview

【解决方案1】：

这是一个如何在QGraphicsScene 中的两个QWidgets 之间画一条线的示例。原则上是直截了当的。小部件的矩形可以通过QGraphicsProxyWidget.geometry() 访问，并且位于场景坐标中。所以可以根据它画一条线。

例子：

from PySide import QtGui, QtCore

app = QtGui.QApplication([])

scene = QtGui.QGraphicsScene()

# put a button into the scene and move it
button1 = QtGui.QPushButton('Button 1')
scene_button1 = scene.addWidget(button1)
r1 = scene_button1.geometry()
r1.moveTo(-100, -50)
scene_button1.setGeometry(r1)

# put another button into the scene
button2 = QtGui.QPushButton('Button 2')
scene_button2 = scene.addWidget(button2)
r2 = scene_button2.geometry()

# add a line between the centers of each rectangles
scene.addLine(r1.x() + r1.width() / 2, r1.y() + r1.height() / 2, r2.x() + r2.width() / 2, r2.y() + r2.height() / 2)

# view on the scene
view = QtGui.QGraphicsView(scene)
view.resize(300, 200)
view.show()

app.exec_()

它看起来像：

现在整个都拖了，因为它不是那么微不足道。不是QGraphicsProxyWidget，而是原来的QWidget，似乎得到了鼠标移动/按下事件。我们只需发出一个新信号（拖动）并将其连接到一个可以移动场景中按钮的函数（使用scene.addWidget 的返回，QGraphicsProxyWidget 也是QGraphicsItem）。它还会重新绘制两个按钮之间的线，以便它们保持连接。

from PySide import QtGui, QtCore

class DraggablePushButton(QtGui.QPushButton):
    """
        Extension of QPushButton that emits a dragged signal (QPointF which is the delta in movement of the mouse) as
        long as it is pressed.
    """

    dragged = QtCore.Signal(QtCore.QPointF)

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)

    def mousePressEvent(self, event):
        self.position = event.globalPos()

    def mouseMoveEvent(self, event):
        # will only by called if the mouse is also pressed
        position_now = event.globalPos()
        self.dragged.emit(position_now - self.position)
        self.position = position_now

def move_scene_button1_and_redraw_line(drag):
    # move the button1 by a certain delta position and change line connecting them with it
    scene_button1.moveBy(drag.x(), drag.y())
    r1 = scene_button1.geometry()
    line_item.setLine(r1.x() + r1.width() / 2, r1.y() + r1.height() / 2, r2.x() + r2.width() / 2, r2.y() + r2.height() / 2)

app = QtGui.QApplication([])

# the graphicsscene
scene = QtGui.QGraphicsScene()
scene.setSceneRect(-150, -100, 300, 200)

# put a draggable button into the scene
button1 = DraggablePushButton('Button 1')
scene_button1 = scene.addWidget(button1)
scene_button1.setPos(-100, -50)
r1 = scene_button1.geometry()

# connect dragged events to move of scene button
button1.dragged.connect(move_scene_button1_and_redraw_line)

# put another still standing button into the scene
button2 = QtGui.QPushButton('Button 2')
scene_button2 = scene.addWidget(button2)
r2 = scene_button2.geometry()

# draw line between button1 and button2
line_item = scene.addLine(r1.x() + r1.width() / 2, r1.y() + r1.height() / 2, r2.x() + r2.width() / 2, r2.y() + r2.height() / 2)

# view on the scene
view = QtGui.QGraphicsView(scene)
view.resize(330, 220)
view.show()

app.exec_()

它仍然看起来像：

【讨论】：

显然在我的情况下并不是那么简单。也许我忘了说一件事：我正在使用 Qt 设计器和一个 pyuic 生成的文件。该文件不应该被编辑，所以我使用“Promote widget”选项，然后创建一个单独的类文件，我在此处发布。我刚刚评论了paintWire方法的大部分内容，并对您的代码进行了sn-p，其中“#在每个矩形的中心之间添加一条线”并且仍然在错误的位置绘制，但至少在不同的位置绘制它.我用图片更新了帖子。
现在我通过将我的自定义“拖动按钮”导入您的代码进行测试。但由于某种原因，我没有得到与导入项目时相同的行为。按钮只是不按预期拖放！至少它应该在拖动时创建一个像素图，或者在即将下降时更改光标图标。为什么？
@Mr_LinDowsMax 我不能说为什么，特别是因为我不知道你的 Dragbuttons。但是我添加了第二个示例，该示例带有一个可拖动的按钮，该按钮使线条与另一个按钮保持连接。它有效。
我在这篇文章中发布了我的 Dragbutton 的代码：stackoverflow.com/q/28258050/598070
正如我上面的评论所说，我相信您的问题完全在于您 DragButton 在右键单击移动时绘制“透明”矩形（但尚未删除）。 Trilarion 的上述代码是一个完整的 sn-p，显示我相信您所期望的操作。 +1 给你@Trilarion。