一个不错的C#程序设计

namespacecomput{//////这是一个计算器的简单实现。///publicclassForm1:System.Windows.Forms.Form{#region控件声明privateSystem.Windows.Forms.TextBoxtxtShow;privateSystem.Windows.Forms.GroupBoxgroupBox1;privateSystem.Windows.Forms.Buttonbtn_rev;privateSystem.Windows.Forms.Butt