QPainter 类

1import sys
2from PyQt6.QtWidgets import QApplication, QWidget
3from PyQt6.QtGui import (QPainter, QPainterPath, QColor, QBrush, QPen,
4                         QFont, QPolygon, QLinearGradient)
5from PyQt6.QtCore import Qt, QPoint, QRect
6
7class Drawing(QWidget):
8    def __init__(self):
9        super().__init__()
10        self.initializeUI()
11
12    def initializeUI(self):
13        self.setFixedSize(600, 600)
14        self.setWindowTitle('QPainter Class')
15        # 创建几种笔的颜色
16        self.black = '#000000'
17        self.blue = '#2041F1'
18        self.green = '#12A708'
19        self.purple = '#6512F0'
20        self.red = '#E00C0C'
21        self.orange = '#FF930A'
22        self.show()
23
24    def paintEvent(self, event):
25        painter = QPainter()
26        painter.begin(self)
27        self.drawPoints(painter)
28        self.drawDiffLines(painter)
29        self.drawText(painter)
30        self.drawRectangles(painter)
31        self.drawPolygons(painter)
32        self.drawRoundedRects(painter)
33        self.drawCurves(painter)
34        self.drawCircles(painter)
35        self.drawGradients(painter)
36        painter.end()
37
38    def drawPoints(self, painter):
39        pen = QPen(QColor(self.black))
40        for i in range(1, 9):
41            pen.setWidth(i * 2)
42            painter.setPen(pen)
43            painter.drawPoint(i * 20, i * 20)
44
45    def drawDiffLines(self, painter):
46        pen = QPen(QColor(self.black), 2)
47        painter.setPen(pen)
48        painter.drawLine(230, 20, 230, 180)
49        pen.setStyle(Qt.PenStyle.DashLine)
50        painter.setPen(pen)
51        painter.drawLine(260, 20, 260, 180)
52        pen.setStyle(Qt.PenStyle.DotLine)
53        painter.setPen(pen)
54        painter.drawLine(290, 20, 290, 180)
55        pen.setStyle(Qt.PenStyle.DashDotLine)
56        painter.setPen(pen)
57        painter.drawLine(320, 20, 320, 180)
58        # 更改笔的颜色和粗细
59        blue_pen = QPen(QColor(self.blue), 4)
60        painter.setPen(blue_pen)
61        painter.drawLine(350, 20, 350, 180)
62        blue_pen.setStyle(Qt.PenStyle.DashDotDotLine)
63        painter.setPen(blue_pen)
64        painter.drawLine(380, 20, 380, 180)
65
66    def drawText(self, painter):
67        text = "Don't look behind."
68        pen = QPen(QColor(self.red))
69        painter.setFont(QFont("Helvetica", 15))
70        painter.setPen(pen)
71        painter.drawText(420, 110, text)
72
73    def drawRectangles(self, painter):
74        pen = QPen(QColor(self.black))
75        brush = QBrush(QColor(self.black))
76        painter.setPen(pen)
77        painter.drawRect(20, 220, 80, 80)
78        painter.setPen(pen)
79        painter.setBrush(brush)
80        painter.drawRect(120, 220, 80, 80)
81        red_pen = QPen(QColor(self.red), 5)
82        green_brush = QBrush(QColor(self.green))
83        painter.setPen(red_pen)
84        painter.setBrush(green_brush)
85        painter.drawRect(20, 320, 80, 80)
86        # 演示如何更改 alpha 通道以实现透明效果
87        blue_pen = QPen(QColor(32, 85, 230, 100), 5)
88        blue_pen.setStyle(Qt.PenStyle.DashLine)
89        painter.setPen(blue_pen)
90        painter.setBrush(green_brush)
91        painter.drawRect(120, 320, 80, 80)
92
93    def drawPolygons(self, painter):
94        pen = QPen(QColor(self.blue), 2)
95        brush = QBrush(QColor(self.orange))
96        points = QPolygon([QPoint(240, 240), QPoint(380, 250),
97                           QPoint(230, 380), QPoint(370, 360)])
98        painter.setPen(pen)
99        painter.setBrush(brush)
100        painter.drawPolygon(points)
101
102    def drawRoundedRects(self, painter):
103        pen = QPen(QColor(self.black))
104        brush = QBrush(QColor(self.black))
105        rect_1 = QRect(420, 340, 40, 60)
106        rect_2 = QRect(480, 300, 50, 40)
107        rect_3 = QRect(540, 240, 40, 60)
108        painter.setPen(pen)
109        brush.setStyle(Qt.BrushStyle.Dense1Pattern)
110        painter.setBrush(brush)
111        painter.drawRoundedRect(rect_1, 8, 8)
112        brush.setStyle(Qt.BrushStyle.Dense5Pattern)
113        painter.setBrush(brush)
114        painter.drawRoundedRect(rect_2, 5, 20)
115        brush.setStyle(Qt.BrushStyle.BDiagPattern)
116        painter.setBrush(brush)
117        painter.drawRoundedRect(rect_3, 15, 15)
118
119    def drawCurves(self, painter):
120        pen = QPen(Qt.GlobalColor.black, 3)
121        brush = QBrush(Qt.GlobalColor.white)
122        path = QPainterPath()
123        path.moveTo(30, 420)
124        path.cubicTo(30, 420, 65, 500, 30, 560)
125        path.lineTo(163, 540)
126        path.cubicTo(125, 360, 110, 440, 30, 420)
127        path.closeSubpath()
128        painter.setPen(pen)
129        painter.setBrush(brush)
130        painter.drawPath(path)
131
132    def drawCircles(self, painter):
133        height, width = self.height(), self.width()
134        center_x, center_y = (width / 2), height - 100
135        radius_x, radius_y = 60, 60
136        pen = QPen(Qt.GlobalColor.black, 2, Qt.PenStyle.SolidLine)
137        brush = QBrush(Qt.GlobalColor.darkMagenta, Qt.BrushStyle.Dense5Pattern)
138        painter.setPen(pen)
139        painter.setBrush(brush)
140        painter.drawEllipse(QPoint(center_x, center_y), radius_x, radius_y)
141
142    def drawGradients(self, painter):
143        pen = QPen(QColor(self.black), 2)
144        gradient = QLinearGradient(450, 480, 520, 550)
145        gradient.setColorAt(0.0, Qt.GlobalColor.blue)
146        gradient.setColorAt(0.5, Qt.GlobalColor.yellow)
147        gradient.setColorAt(1.0, Qt.GlobalColor.cyan)
148        painter.setPen(pen)
149        painter.setBrush(QBrush(gradient))
150        painter.drawRect(420, 420, 160, 160)
151
152if __name__ == '__main__':
153    app = QApplication(sys.argv)
154    window = Drawing()
155    sys.exit(app.exec())