此程序展示了如何在wpf中使用渐变笔刷绘制用户界面，GradientBrush使用两种以上的颜色结合渐变点offset设置来填充绘图区域。-This program shows how to use the gradient brush in wpf drawing the user interface, GradientBrush the use of two or more colors in conjunction with gradient-point offset is set to