這個例子我做了好幾天：

1）官網(wǎng)C++的源碼，改寫成PyQt5版本的代碼，好多細節(jié)不會轉化

2）網(wǎng)上的PyQt的例子根本運行不了

填了無數(shù)個坑，結合二者，終于能完成了一個關于繪圖的東西。這個過程也掌握了很多新的知識點

【知識點】

1、關于多個點的使用

poitns = [QPoint(10, 80), QPoint(20, 10), QPoint(80, 30), QPoint(90, 70)]

請看：

# 定義多個點   points = [QPoint(10, 80), QPoint(20, 10), QPoint(80, 30), QPoint(90, 70)]   # ===直接使用 points 會報錯！=========   # ...   elif self.shape == self.Points:      painter.drawPoints(points)   elif self.shape == self.Polyline:      painter.drawPolyline(points)   elif self.shape == self.Polygon:      painter.drawPolygon(points, 4)   # ...   # ===把 points 用 QPolygon()包裹起來才正確！=========   # ...   elif self.shape == self.Points:      painter.drawPoints(QPolygon(points))   elif self.shape == self.Polyline:      painter.drawPolyline(QPolygon(points))   elif self.shape == self.Polygon:      painter.drawPolygon(QPolygon(points), 4)   # ...

2、在QDialog窗體中顯示QWidget部件

【效果圖】

【資源】

//files.jb51.net/file_images/article/201710/brick.png
//files.jb51.net/file_images/article/201710/qt-logo.png

【代碼】

import sysfrom PyQt5.QtCore import *from PyQt5.QtGui import *from PyQt5.QtWidgets import *class StockDialog(QWidget):  def __init__(self, parent=None):    super(StockDialog, self).__init__(parent)    self.setWindowTitle("利用QPainter繪制各種圖形")        mainSplitter = QSplitter(Qt.Horizontal)    mainSplitter.setOpaqueResize(True)             frame = QFrame(mainSplitter)    mainLayout = QGridLayout(frame)    #mainLayout.setMargin(10)    mainLayout.setSpacing(6)    label1=QLabel("形狀：")    label2=QLabel("畫筆線寬：")    label3=QLabel("畫筆顏色：")    label4=QLabel("畫筆風格：")    label5=QLabel("畫筆頂端：")    label6=QLabel("畫筆連接點：")    label7=QLabel("畫刷風格：")    label8=QLabel("畫刷顏色：")      self.shapeComboBox = QComboBox()    self.shapeComboBox.addItem("Line", "Line")    self.shapeComboBox.addItem("Rectangle", "Rectangle")    self.shapeComboBox.addItem('Rounded Rectangle','Rounded Rectangle')    self.shapeComboBox.addItem('Ellipse','Ellipse')    self.shapeComboBox.addItem('Pie','Pie')    self.shapeComboBox.addItem('Chord','Chord')    self.shapeComboBox.addItem('Path','Path')    self.shapeComboBox.addItem('Polygon','Polygon')    self.shapeComboBox.addItem('Polyline','Polyline')    self.shapeComboBox.addItem('Arc','Arc')    self.shapeComboBox.addItem('Points','Points')    self.shapeComboBox.addItem('Text','Text')    self.shapeComboBox.addItem('Pixmap','Pixmap')        self.widthSpinBox = QSpinBox()    self.widthSpinBox.setRange(0,20)        self.penColorFrame = QFrame()    self.penColorFrame.setAutoFillBackground(True)    self.penColorFrame.setPalette(QPalette(Qt.blue))    self.penColorPushButton = QPushButton("更改")        self.penStyleComboBox = QComboBox()    self.penStyleComboBox.addItem("Solid",Qt.SolidLine)    self.penStyleComboBox.addItem('Dash', Qt.DashLine)    self.penStyleComboBox.addItem('Dot', Qt.DotLine)    self.penStyleComboBox.addItem('Dash Dot', Qt.DashDotLine)    self.penStyleComboBox.addItem('Dash Dot Dot', Qt.DashDotDotLine)    self.penStyleComboBox.addItem('None', Qt.NoPen)        self.penCapComboBox = QComboBox()    self.penCapComboBox.addItem("Flat",Qt.FlatCap)    self.penCapComboBox.addItem('Square', Qt.SquareCap)    self.penCapComboBox.addItem('Round', Qt.RoundCap)        self.penJoinComboBox = QComboBox()    self.penJoinComboBox.addItem("Miter",Qt.MiterJoin)    self.penJoinComboBox.addItem('Bebel', Qt.BevelJoin)    self.penJoinComboBox.addItem('Round', Qt.RoundJoin)        self.brushStyleComboBox = QComboBox()    self.brushStyleComboBox.addItem("Linear Gradient",Qt.LinearGradientPattern)    self.brushStyleComboBox.addItem('Radial Gradient', Qt.RadialGradientPattern)    self.brushStyleComboBox.addItem('Conical Gradient', Qt.ConicalGradientPattern)    self.brushStyleComboBox.addItem('Texture', Qt.TexturePattern)    self.brushStyleComboBox.addItem('Solid', Qt.SolidPattern)    self.brushStyleComboBox.addItem('Horizontal', Qt.HorPattern)    self.brushStyleComboBox.addItem('Vertical', Qt.VerPattern)    self.brushStyleComboBox.addItem('Cross', Qt.CrossPattern)    self.brushStyleComboBox.addItem('Backward Diagonal', Qt.BDiagPattern)    self.brushStyleComboBox.addItem('Forward Diagonal', Qt.FDiagPattern)    self.brushStyleComboBox.addItem('Diagonal Cross', Qt.DiagCrossPattern)    self.brushStyleComboBox.addItem('Dense 1', Qt.Dense1Pattern)    self.brushStyleComboBox.addItem('Dense 2', Qt.Dense2Pattern)    self.brushStyleComboBox.addItem('Dense 3', Qt.Dense3Pattern)    self.brushStyleComboBox.addItem('Dense 4', Qt.Dense4Pattern)    self.brushStyleComboBox.addItem('Dense 5', Qt.Dense5Pattern)    self.brushStyleComboBox.addItem('Dense 6', Qt.Dense6Pattern)    self.brushStyleComboBox.addItem('Dense 7', Qt.Dense7Pattern)    self.brushStyleComboBox.addItem('None', Qt.NoBrush)        self.brushColorFrame = QFrame()    self.brushColorFrame.setAutoFillBackground(True)    self.brushColorFrame.setPalette(QPalette(Qt.green))    self.brushColorPushButton = QPushButton("更改")                                   labelCol=0    contentCol=1        #建立布局    mainLayout.addWidget(label1,1,labelCol)    mainLayout.addWidget(self.shapeComboBox,1,contentCol)    mainLayout.addWidget(label2,2,labelCol)    mainLayout.addWidget(self.widthSpinBox,2,contentCol)    mainLayout.addWidget(label3,4,labelCol)    mainLayout.addWidget(self.penColorFrame,4,contentCol)    mainLayout.addWidget(self.penColorPushButton,4,3)    mainLayout.addWidget(label4,6,labelCol)    mainLayout.addWidget(self.penStyleComboBox,6,contentCol)    mainLayout.addWidget(label5,8,labelCol)    mainLayout.addWidget(self.penCapComboBox,8,contentCol)    mainLayout.addWidget(label6,10,labelCol)    mainLayout.addWidget(self.penJoinComboBox,10,contentCol)    mainLayout.addWidget(label7,12,labelCol)    mainLayout.addWidget(self.brushStyleComboBox,12,contentCol)    mainLayout.addWidget(label8,14,labelCol)    mainLayout.addWidget(self.brushColorFrame,14,contentCol)    mainLayout.addWidget(self.brushColorPushButton,14,3)    mainSplitter1 = QSplitter(Qt.Horizontal)    mainSplitter1.setOpaqueResize(True)        stack1 = QStackedWidget()    stack1.setFrameStyle(QFrame.Panel|QFrame.Raised)    self.area = PaintArea()    stack1.addWidget(self.area)        frame1 = QFrame(mainSplitter1)    mainLayout1 = QVBoxLayout(frame1)    #mainLayout1.setMargin(10)    mainLayout1.setSpacing(6)    mainLayout1.addWidget(stack1)    layout = QGridLayout(self)    layout.addWidget(mainSplitter1,0,0)    layout.addWidget(mainSplitter,0,1)    self.setLayout(layout)        #信號和槽函數(shù)    self.shapeComboBox.activated.connect(self.slotShape)    self.widthSpinBox.valueChanged.connect(self.slotPenWidth)    self.penColorPushButton.clicked.connect(self.slotPenColor)    self.penStyleComboBox.activated.connect(self.slotPenStyle)    self.penCapComboBox.activated.connect(self.slotPenCap)    self.penJoinComboBox.activated.connect(self.slotPenJoin)    self.brushStyleComboBox.activated.connect(self.slotBrush)    self.brushColorPushButton.clicked.connect(self.slotBrushColor)        self.slotShape(self.shapeComboBox.currentIndex())    self.slotPenWidth(self.widthSpinBox.value())    self.slotBrush(self.brushStyleComboBox.currentIndex())          def slotShape(self,value):    shape = self.area.Shape[value]    self.area.setShape(shape)    def slotPenWidth(self,value):    color = self.penColorFrame.palette().color(QPalette.Window)    style = Qt.PenStyle(self.penStyleComboBox.itemData(self.penStyleComboBox.currentIndex(),Qt.UserRole))    cap = Qt.PenCapStyle(self.penCapComboBox.itemData(self.penCapComboBox.currentIndex(),Qt.UserRole))    join = Qt.PenJoinStyle(self.penJoinComboBox.itemData(self.penJoinComboBox.currentIndex(),Qt.UserRole))    self.area.setPen(QPen(color,value,style,cap,join))    def slotPenStyle(self,value):    self.slotPenWidth(value)    def slotPenCap(self,value):    self.slotPenWidth(value)    def slotPenJoin(self,value):    self.slotPenWidth(value)    def slotPenColor(self):    color = QColorDialog.getColor(Qt.blue)    self.penColorFrame.setPalette(QPalette(color))    self.area.setPen(QPen(color))      def slotBrushColor(self):    color = QColorDialog.getColor(Qt.blue)    self.brushColorFrame.setPalette(QPalette(color))    self.slotBrush(self.brushStyleComboBox.currentIndex())    def slotBrush(self,value):    color = self.brushColorFrame.palette().color(QPalette.Window)    style = Qt.BrushStyle(self.brushStyleComboBox.itemData(value,Qt.UserRole))        if(style == Qt.LinearGradientPattern):      linearGradient = QLinearGradient(0,0,400,400)      linearGradient.setColorAt(0.0,Qt.white)      linearGradient.setColorAt(0.2,color)      linearGradient.setColorAt(1.0,Qt.black)      self.area.setBrush(linearGradient)    elif style ==Qt.RadialGradientPattern:      radialGradient = QRadialGradient(200, 200, 80, 70, 70);      radialGradient.setColorAt(0.0, Qt.white)      radialGradient.setColorAt(0.2, Qt.green)      radialGradient.setColorAt(1.0, Qt.black)      self.area.setBrush(radialGradient)    elif(style == Qt.ConicalGradientPattern):      conicalGradient = QConicalGradient(200,200,30)      conicalGradient.setColorAt(0.0,Qt.white)      conicalGradient.setColorAt(0.2,color)      conicalGradient.setColorAt(1.0,Qt.black)      self.area.setBrush(conicalGradient)    elif(style == Qt.TexturePattern):      self.area.setBrush(QBrush(QPixmap("images/brick.png")))    else:      self.area.setBrush(QBrush(color,style))      class PaintArea(QWidget):  def __init__(self):    super(PaintArea,self).__init__()    self.Shape = ["Line","Rectangle", 'Rounded Rectangle', "Ellipse", "Pie", 'Chord',   "Path","Polygon", "Polyline", "Arc", "Points", "Text", "Pixmap"]    self.setPalette(QPalette(Qt.white))    self.setAutoFillBackground(True)    self.setMinimumSize(400,400)    self.pen = QPen()    self.brush = QBrush()        def setShape(self,s):    self.shape = s    self.update()      def setPen(self,p):    self.pen = p    self.update()    def setBrush(self,b):    self.brush = b    self.update()    def paintEvent(self,QPaintEvent):    p = QPainter(self)    p.setPen(self.pen)    p.setBrush(self.brush)        rect = QRect(50,100,300,200)     points = [QPoint(150,100),QPoint(300,150),QPoint(350,250),QPoint(100,300)]    startAngle = 30 * 16    spanAngle = 120 * 16        path = QPainterPath();    path.addRect(150,150,100,100)    path.moveTo(100,100)    path.cubicTo(300,100,200,200,300,300)    path.cubicTo(100,300,200,200,100,100)        if self.shape == "Line":      p.drawLine(rect.topLeft(),rect.bottomRight())    elif self.shape == "Rectangle":      p.drawRect(rect)    elif self.shape == 'Rounded Rectangle':      p.drawRoundedRect(rect, 25, 25, Qt.RelativeSize)    elif self.shape == "Ellipse":      p.drawEllipse(rect)    elif self.shape == "Polygon":      p.drawPolygon(QPolygon(points),Qt.WindingFill)    elif self.shape == "Polyline":      p.drawPolyline(QPolygon(points))    elif self.shape == "Points":      p.drawPoints(QPolygon(points))    elif self.shape == "Pie":      p.drawPie(rect, startAngle, spanAngle)    elif self.shape == "Arc":      p.drawArc(rect,startAngle,spanAngle)    elif self.shape == "Chord":      p.drawChord(rect, startAngle, spanAngle)    elif self.shape == "Path":      p.drawPath(path)    elif self.shape == "Text":      p.drawText(rect,Qt.AlignCenter,"Hello Qt!")    elif self.shape == "Pixmap":      p.drawPixmap(150,150,QPixmap("images/qt-logo.png"))    if __name__=='__main__':  app = QApplication(sys.argv)  form = StockDialog()  form.show()  app.exec_()