数据库技术与应用

namespace WinFormsApp2
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        private void textBox2_KeyPress(object sender, KeyPressEventArgs e)  //事件textbox2按了enter键
        {
            if (e.KeyChar == 13)   //为enter键
            {
                int a, b;
                bool toushu = int.TryParse(textBox1.Text, out a);  
                bool jiaoshu = int.TryParse(textBox2.Text, out b); //头、脚数是否可以转为整型
                if (toushu == true & jiaoshu == true)   
                {
                    float c, d;  
                    c = 2 * a - b / 2;  //方程的鸡解
                    d = b / 2 - a;      //方程的兔解
                    string str1 = c.ToString();     
                    string str2 = d.ToString();     //转换为字符串
                    int C, D;
                    bool jishu = int.TryParse(str1, out C);   //解是否可以转换为整型
                    bool tushu = int.TryParse(str2, out D);
                    if (jishu == true & tushu == true & C >= 0 & D >= 0)  //合理解
                        label4.Text = "     "+str1 + "     " +str2;    //输出
                    else 
                        MessageBox.Show("error");

                }
                else
                    MessageBox.Show("error");
            }
        }
    }
}

鸡兔同笼问题用C#解决

 输入脚数之后按回车键即可算出答案