PyQt5绘图API大全
1、绘图API:绘制文本
#1.文本 2.各种图形 3.图像
#QPainter painter=QPainter() painter.begin() painter.end() painter.drawtext() 必须在painevent事件方法中绘制各种元素

import sys
from PyQt5.QtWidgets import QApplication,QWidget
from PyQt5.QtCore import Qt
from PyQt5.QtGui import QPainter,QColor,QFont
class Drawtext(QWidget):
    def __init__(self):
        super(Drawtext,self).__init__()
        self.setWindowTitle("在窗口上面绘制文直线文本")
        self.resize(500,200)
        self.text="Python从菜鸟到高手"

    def paintEvent(self,event):
        painter=QPainter(self)  #定义一个画布
        painter.begin(self)  #初始化画布属性
        print("绘图函数已经调用")
        painter.setPen(QColor(150,43,5))                 #设置画笔的属性颜色
        painter.setFont(QFont("SimSun",25))              #设置绘画显示字体

        painter.drawText(event.rect(),Qt.AlignCenter,self.text)  #设置绘画区域范围
        painter.end()
if __name__=="__main__":
    app=QApplication(sys.argv)
    p=Drawtext()
    p.show()
    sys.exit(app.exec_())

2、绘制各种图形（圆，矩形，多边形，各种函数图形，椭圆，圆，弧线等）
import sys,math
from PyQt5.QtWidgets import *
from PyQt5.QtGui import *
from PyQt5.QtCore import *
class Drawall(QWidget):
    def __init__(self):
        super(Drawall,self).__init__()
        self.setWindowTitle("绘制各种图形")
        self.resize(300,600)
    def paintEvent(self,event):
        painter=QPainter(self)   #先定义画布
        painter.begin(self)      #初始化画布

        painter.setPen(Qt.blue)

        #绘制弧线
        rect=QRect(0,10,100,100)                  #确定画出圆弧的正方形区域(x左上角横坐标，y左上角纵坐标，length矩形长，width矩形宽)
        #alen参数：1个alen长度等于1/16度
        painter.drawArc(rect,0,90*16)             #绘制圆弧的角度范围（矩形区域，起始角度，终止角度）
        #通过弧线来绘制圆
        painter.setPen(Qt.red)
        painter.drawArc(120,10,100,100,0,360*16)  #圆的半径大小可以通过设置矩形区域的长宽大小来进行设置
        #绘制带弦的弧线
        painter.drawChord(10,120,100,100,12,130*16)
        # 绘制扇形
        painter.drawPie(10,240,100,100,12,130*16)
        #绘制椭圆
        painter.drawEllipse(120,120,100,150)

        #绘制多边形(定义多边形的顶点坐标)
        point1=QPoint(140,380)
        point2=QPoint(270,420)
        point3=QPoint(290,512)
        point4=QPoint(290,588)
        point5=QPoint(200,533)
        polygon=QPolygon([point1,point2,point3,point4,point5])
        painter.drawPolygon(polygon)

        #绘制图像
        image=QImage("./image-1/1-1.jpg")
        rect=QRect(10,400,image.width()/15,image.height()/15)      #在某个定义好的区域画出图像大小
        painter.drawImage(rect,image)                              #绘制图像函数参数设置
        painter.end()

if __name__=="__main__":
    app=QApplication(sys.argv)
    p=Drawall()
    p.show()
    sys.exit(app.exec_())

3、绘制像素点正弦曲线
import sys,math
from PyQt5.QtWidgets import *
from PyQt5.QtGui import *
from PyQt5.QtCore import Qt
class Drawpoints(QWidget):
    def __init__(self):
        super(Drawpoints,self).__init__()
        self.setWindowTitle("窗口像素点绘制正弦曲线")
        self.resize(300,200)
    def paintEvent(self,event):
        painter=QPainter(self)

        painter.begin(self)
        painter.setPen(Qt.blue)
        size=self.size()

        for i in range(100):
            x=100*(-1+2.0*i/100)+size.width()/2.0                              #将主窗口的宽度中心作为x周轴原点
            y=-50*math.sin((x-size.width()/2.0)*math.pi/50)+size.height()/2.0  #将主窗口的高度中心作为x周轴原点
            painter.drawPoint(x,y)

        painter.end()

if __name__=="__main__":
    app=QApplication(sys.argv)
    p=Drawpoints()
    p.show()
    sys.exit(app.exec_())

4、绘制不同类型的直线，主要是指对于直线的样式的设置，对于pen样式的设置
import sys,math
from PyQt5.QtWidgets import *
from PyQt5.QtGui import *
from PyQt5.QtCore import Qt
class Drawmultiline(QWidget):
    def __init__(self):
        super(Drawmultiline,self).__init__()
        self.setWindowTitle("设置pen的样式")
        self.resize(300,300)
    def paintEvent(self,event):
        painter=QPainter(self)

        painter.begin(self)
        pen=QPen(Qt.red,2,Qt.SolidLine)  #设置实线样式直线
        painter.setPen(pen)
        painter.drawLine(20,40,250,40)

        pen.setStyle(Qt.DashLine)       #设置宽虚线样式直线
        painter.setPen(pen)
        painter.drawLine(20, 80, 250, 80)

        pen.setStyle(Qt.DashDotDotLine)  # 设置双点划线线样式直线
        painter.setPen(pen)
        painter.drawLine(20, 120, 250, 120)

        pen.setStyle(Qt.DashDotLine)  # 设置单点划线线样式直线
        painter.setPen(pen)
        painter.drawLine(20, 160, 250, 160)

        pen.setStyle(Qt.DotLine)      # 设置窄虚线样式直线
        painter.setPen(pen)
        painter.drawLine(20, 200, 250, 200)

        pen.setStyle(Qt.CustomDashLine)  # 自定义样式直线,可以使用列表中数值比例来进行设置
        pen.setDashPattern([1,10,5,4])
        painter.setPen(pen)
        painter.drawLine(20, 240, 250, 240)

        size=self.size()
        painter.end()

if __name__=="__main__":
    app=QApplication(sys.argv)
    p=Drawmultiline()
    p.show()
    sys.exit(app.exec_())

5、用画刷填充区域
import sys,math
from PyQt5.QtWidgets import *
from PyQt5.QtGui import *
from PyQt5.QtCore import *
class Fillrect(QWidget):
    def __init__(self):
        super(Fillrect,self).__init__()
        self.setWindowTitle("用画刷填充区域")
        self.resize(900,600)



    def paintEvent(self,event):
        painter=QPainter(self)   #先定义画布
        painter.begin(self)      #初始化画布
        brush=QBrush(Qt.SolidPattern)  #定义实心画刷样式
        painter.setBrush(brush)
        painter.drawRect(10,15,90,60)

        brush = QBrush(Qt.Dense1Pattern)  # 定义实心画刷样式1
        painter.setBrush(brush)
        painter.drawRect(120, 15, 90, 60)

        brush = QBrush(Qt.Dense2Pattern)  # 定义实心画刷样式2
        painter.setBrush(brush)
        painter.drawRect(230, 15, 90, 60)

        brush = QBrush(Qt.Dense3Pattern)  # 定义实心画刷样式3
        painter.setBrush(brush)
        painter.drawRect(340, 15, 90, 60)
        brush = QBrush(Qt.Dense4Pattern)  # 定义实心画刷样式4
        painter.setBrush(brush)
        painter.drawRect(450, 15, 90, 60)
        brush = QBrush(Qt.Dense5Pattern)  # 定义实心画刷样式5
        painter.setBrush(brush)
        painter.drawRect(560, 15, 90, 60)
        brush = QBrush(Qt.Dense6Pattern)  # 定义实心画刷样式6
        painter.setBrush(brush)
        painter.drawRect(670, 15, 90, 60)
        brush = QBrush(Qt.Dense7Pattern)  # 定义实心画刷样式7
        painter.setBrush(brush)
        painter.drawRect(780, 15, 90, 60)
        painter.end()


if __name__=="__main__":
    app=QApplication(sys.argv)
    p=Fillrect()
    p.show()
    sys.exit(app.exec_())

PyQt5绘图API