Create a pie chart using GDI + or provide some examples:

The first one is relatively simple:
Tutorial: vs2008 C # Pie Chart

Http://forum.codecall.net/csharp-tutorials/7917-tutorial-vs2008-c-pie-chart.html

This does not seem complicated:
Drawing a dynamic chart in C #

Http://www.codeproject.com/KB/graphics/charting.aspx

This is complicated, but it is just a library. Maybe you can use it directly:

A flexible charting library for. net

Http://www.codeproject.com/KB/graphics/zedgraph.aspx

Zedgrap is also available

Http://www.cnblogs.com/82767136/articles/1205436.html

Http://www.cnblogs.com/levin9/articles/791129.html

Http://www.cnblogs.com/dahuzizyd/archive/2006/12/20/Excel_Chart_3.html

Http://blog.csdn.net/lanmao100/archive/2007/10/26/1845620.aspx

Here is a hands-on tutorial.

Http://hi.baidu.com/%C8%FC%C4%C9%D0%D0%D0%C7/blog/item/dca89efb91d232136d22eb91.html

. Net uses the dotnetcharting control to generate a Statistical Chart Summary of reports.

Http://www.cnblogs.com/dreamof/archive/2008/07/18/1245887.html