1.QBrush简介

PyQt5中QBrush 是一个用于绘制图形的工具。QBrush 对象主要用于定义图形的填充方式，比如颜色、纹理等。与 QPainter 对象一起使用，QBrush 负责在窗口或小部件上绘制图形。。

2.QBrush案例

import sys
from PyQt5.QtWidgets import QApplication, QWidget,QVBoxLayout
from PyQt5.QtGui import QPainter, QColor, QBrush, QLinearGradient
from PyQt5.QtCore import Qt


class QBrushDemo(QWidget):
    def __init__(self):
        super().__init__()
        self.setWindowTitle('填充区域')
        self.resize(600, 400)

    def paintEvent(self, event):
        qp = QPainter()
        qp.begin(self)

        brush = QBrush(Qt.SolidPattern)  # 实心绘制
        brush.setColor(QColor(Qt.red))  # 设置颜色
        qp.setBrush(brush)  # 设置笔刷
        qp.drawRect(5, 5, 90, 90)  # 绘制图形，(x,y,w,h)

        brush = QBrush(Qt.Dense1Pattern)
        brush.setColor(QColor(Qt.red))
        qp.setBrush(brush)
        qp.drawRect(100, 5, 90, 90)

        brush = QBrush(Qt.Dense2Pattern)
        brush.setColor(QColor(Qt.red))
        qp.setBrush(brush)
        qp.drawRect(200, 5, 90, 90)

        brush = QBrush(Qt.HorPattern)
        brush.setColor(QColor(Qt.red))
        qp.setBrush(brush)
        qp.drawRect(5, 100, 90, 90)

        brush = QBrush(Qt.DiagCrossPattern)
        brush.setColor(QColor(Qt.red))
        qp.setBrush(brush)
        qp.drawRect(100, 100, 90, 90)

        brush = QBrush(Qt.FDiagPattern)
        brush.setColor(QColor(Qt.red))
        qp.setBrush(brush)
        qp.drawRect(200, 100, 90, 90)

        # 渐变填充，QLinearGradient 的起始点设置为 (5, 200)，结束点设置为 (95, 295)，
        gradient = QLinearGradient(5, 200, 95, 295)

        # 设置渐变的起始颜色和结束颜色
        gradient.setColorAt(0, QColor("red"))
        gradient.setColorAt(1, QColor("blue"))

        # 设置画刷的渐变
        qp.setBrush(gradient)

        # 绘制矩形，并填充。
        qp.drawRect(5, 200, 90, 90)

        qp.end()


if __name__ == '__main__':
    app = QApplication(sys.argv)
    w = QBrushDemo()
    w.show()
    app.exec()

3.运行结果

4.部分填充样式