用C#编写：提示用户输入1~7之间的整数，读取用户所输数值，输出相应的星期值。

class Program
{
static void Main(string[] args)
{
int dayNum = -1;
Console.WriteLine("输入一个数字:");
try
{
dayNum = Convert.ToInt32(Console.ReadLine());
}
catch (FormatException ex)
{
Console.WriteLine(ex.Message);
Console.ReadKey();
return;
}

switch (dayNum)
{
case 1:
Console.WriteLine("星期一");
break;
case 2:
Console.WriteLine("星期二");
break;
case 3:
Console.WriteLine("星期三");
break;
case 4:
Console.WriteLine("星期四");
break;
case 5:
Console.WriteLine("星期五");
break;
case 6:
Console.WriteLine("星期六");
break;
case 7:
Console.WriteLine("星期日");
break;
default:
Console.WriteLine("输入的数字有误！");
break;
}

Console.ReadKey();
}
}