我改写后的graphbrian类，原本支持柱状图饼图和折线图的，现在添加了对这些图的风格调整，主要是增加了调整绘图区背景色和文本背景的功能，还增加了把图片保存为bmp文件的功能，以便用其他软件方便的打印。-I would then graphbrian category, which originally supported the pie chart histogram and line graph, and now added to adjust the style of these pla