C#计算器

代码说明：

using System; using System.Drawing; using System.Collections; using System.ComponentModel; using System.Windows.Forms; using System.Data; using System.Runtime.InteropServices; using System.IO; namespace 计算器 { /// /// Form1 的摘要说明。 /// public class Form1 : System.Windows.Forms.Form { private System.Windows.Forms.TextBox textBox1; private System.Windows.Forms.Label label1; private System.Windows.Forms.Button button1; private System.Windows.Forms.Button button2; private System.Windows.Forms.Button button3; private System.Windows.Forms.Button button4; private System.Windows.Forms.Button button5; private System.Windows.Forms.Button button6; private System.Windows.Forms.Button button7; private System.Windows.Forms.Button button8; private System.Windows.Forms.Button button9; private System.Windows.Forms.Button button11; private System.Windows.For