移動時QGraphicItem未正確繪製

以下PyQt4應用程序的問題在於，當我拖動它們時，它移動的項目太多 - 實際移動鼠標指針的量增加了一倍，所以當我在畫布上拖動項目時，在一個方向上「足夠的移動」之後，鼠標指針在項目的邊界框外部結束。移動時QGraphicItem未正確繪製

我在做什麼錯？我不重寫任何大的改動，你可以看到：

主窗口：

from PyQt4.QtCore import * 
from PyQt4.QtGui import * 
from grapheditor.ui_mainwindow import Ui_MainWindow 
from grapheditor.customwidgets import GraphViewer 
from grapheditor.graphholder import GraphHolder 
from grapheditor.graphnode import GraphNode 

class MainWindow(QMainWindow): 
    def __init__(self, parent=None): 
     super(MainWindow, self).__init__(parent) 
     self.ui = Ui_MainWindow() 
     self.ui.setupUi(self) 
     self.showMaximized() 
     QTimer.singleShot(0, self.setup) 
    def setup(self): 
     self.scene = GraphHolder() 
     self.ui.graphicsView.setScene(self.scene) 
     #self.ui.graphicsView.setSceneRect(0, 0, 1500, 1500) 
     self.drawItems() 
    def drawItems(self): 
     QGraphicsLineItem(0, -10, 0, 1000, None, self.scene) 
     QGraphicsLineItem(-10, 0, 1000, 0, None, self.scene) 
     item = GraphNode("hello", 0, 0, 30, 40) 
     self.scene.addItem(item) 

    def getCanvas(self): 
     return self.ui.graphicsView

視圖

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

class GraphViewer(QGraphicsView): 
    def __init__(self, parent=None): 
     super(GraphViewer, self).__init__(parent) 
     self.setInteractive(True)

該項目

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

class GraphNode(QGraphicsItem): 
    penWidth = 2 
    cornerRadius = 10 
    def __init__(self, ident, x, y, width, height, parent=None): 
     super(GraphNode, self).__init__(parent) 
     self.ident = ident 
     self.setPos(x, y) 
     self.width = width 
     self.height = height 
     self.setFlags(QGraphicsItem.ItemIsMovable|QGraphicsItem.ItemIsSelectable) 

    def boundingRect(self): 
     return QRectF(self.pos().x() - self.penWidth/2, self.pos().y() - self.penWidth/2,self.width + self.penWidth, self.height + self.penWidth) 

    def paint(self, painter, optiongraphicsitem, widget): 
     painter.drawRoundedRect(self.pos().x(), self.pos().y(), self.width, self.height, self.cornerRadius, self.cornerRadius) 
     painter.drawRect(self.boundingRect())

場景僅僅是現在爲空班：

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

class GraphHolder(QGraphicsScene): 
    def __init__(self, parent=None): 
     super(GraphHolder, self).__init__(parent)

來源

2013-11-01 Flavius

您的boundingRect的實施不正確。 boundingRect應該返回項目座標系中的座標。場景會將項目位置添加到邊界矩形以計算實際項目位置。綁定矩形不能取決於self.pos()。在你的情況下，這個錯誤會導致項目的雙重添加和不正確的定位。正確實施：

def boundingRect(self): 
    return QRectF(-self.penWidth/2, -self.penWidth/2, 
       self.width + self.penWidth, self.height + self.penWidth)

來源

2013-11-01 11:01:28

移動時QGraphicItem未正確繪製

回答

相關問題