要绘制HSV取色板，一般通过绘制前景色和背景色的方式实现，先绘制前景，然后绘制背景，前景是HSV颜色空间，从左到右，背景是亮度，从上到下，xs和ys是鼠标的当前的位置。
def graphicsView_rgb_palette(self,xs,ys): try: rect = QRectF(0, 0, self.graphicsView_color_palette.width() - 2, self.graphicsView_color_palette.height() - 2) self.graphicsView_color_palette_scene = QGraphicsScene(rect) # 创建场景 self.graphicsView_color_palette.setScene(self.graphicsView_color_palette_scene) #前景，HSV空间 ，从360到0 colorGradient = QLinearGradient(0, 0, self.graphicsView_color_palette.width(),0) colorGradient.setSpread(QGradient.RepeatSpread); colorGradient.setColorAt(0, QColor(255, 0, 0, 255)); colorGradient.setColorAt(0.166, QColor(255, 255, 0, 255)); colorGradient.setColorAt(0.333, QColor(0, 255, 0, 255)); colorGradient.setColorAt(0.5, QColor(0, 255, 255, 255)); colorGradient.setColorAt(0.666, QColor(0, 0, 255, 255)); colorGradient.setColorAt(0.833, QColor(255, 0, 255, 255)); colorGradient.setColorAt(1, QColor(255, 0, 0, 255)); #背景，调节亮度，最上面透明，最下面白色 blackGradient = QLinearGradient(0, 0, 0,self.graphicsView_color_palette.height()) blackGradient.setSpread(QGradient.RepeatSpread); blackGradient.setColorAt(0,QColor(0,0,0,0)); blackGradient.setColorAt(1, QColor(255,255,255,250)); #绘制取色板鼠标指示点 item = QGraphicsEllipseItem(-10, -10, 20, 20) # 创建椭圆--场景坐标 item.setPos(xs, ys) # 给图元设置在场景中的坐标(移动图元)--图元中心坐标 item.setBrush(Qt.black) # 设置画刷 # self.graphicsView_color_palette_scene.setBackgroundBrush(colorGradient); #设置前景色 self.graphicsView_color_palette_scene.setForegroundBrush(blackGradient); #设置背景色 self.graphicsView_color_palette_scene.addItem(item) self.graphicsView_color_palette_scene.clearSelection() # 【清除选择】 except Exception as e: self.UART_Display_Text(str(e))