说明：  GDI+：Graphics Device Interface (图形设备接口)，它提 供了高级图形图像处理功能  在C#中，通过一套部署为托管代码的类来展现提供的图 形图像处理功能，这套类被称为GDI+的托管类。利用 GDI+可以轻松实现颜色渐变、透明处理、纹理处理、拉 伸和缩放等多种高级功能。  GDI+主要提供了三类服务： 1.二维矢量图形 2.图像处理 3.文字显示
(GDI+: Graphics Device Interface (Graphics Device Interface), which provides advanced graphics image processing function  to show graphics image processing function provided by a deployment of managed code classes in C#, set class is called GDI+ Managed classes. Using GDI+ can easily achieve color gradient, transparent processing, texture processing, stretching and scaling and other advanced features. The  GDI+ provide three types of services: 1 two-dimensional vector graphics image processing 3. Text)