VB实现的倒计时类代码详解

Module Module1 
Sub Main() 
Dim a As Date 
Dim h, m, s As Integer 
Dim n, i As Long 
Dim x, z As Long 
Dim y As Long 
Console.WriteLine("本程序为倒计时程序，请分部输入需要倒数的小时数、分钟数、秒数") 
Console.WriteLine("请输入计时的小时数（大于等于0的整数）：") 
h = Console.ReadLine() 
Console.WriteLine("请输入计时的总分钟数（大于等于0并且小于60的整数）：") 
m = Console.ReadLine() 
Console.WriteLine("请输入计时的秒数（大于等于0的并且小于60的整数）：") 
s = Console.ReadLine() 
Console.WriteLine("当前系统时间为：{0}", h) 
a = Now() 
Console.WriteLine("当前系统时间为：{0}", a) 
Console.WriteLine(" ") 
Console.WriteLine(" **************倒计时开始***************** ") 
Console.WriteLine(" **************倒计时开始***************** ") 
Console.WriteLine(" **************倒计时开始***************** ") 
Console.WriteLine(" **************倒计时开始***************** ") 
z = 0 
x = 60 
For i = 0 To h * 3600 + m * 60 + s 
For n = 0 To 6000000 
For y = 0 To 25 
z = z + 1 
Next 
Next 
If (h <= 0) And (m <= 0) And (s <= 0) Then Exit For 
If s > 0 Then 
s = s - 1 
Console.WriteLine(" 剩余：{0}小时{1}分{2}秒", h, m, s) 
If (h <= 0) And (m <= 0) And (s <= 0) Then 
Console.WriteLine("倒计时完毕，随意输入字符将退出程序：") 

Exit For 
End If 
End If 
If s = 0 Then 
If m > 0 Then 
m = m - 1 
s = 59 
Console.WriteLine(" 剩余：{0}小时{1}分{2}秒 ", h, m, s) 
End If 

If m = 0 And h > 0 And s = 0 Then 
h = h - 1 
m = 59 
s = 59 
Console.WriteLine(" 剩余：{0}小时{1}分{2}秒 ", h, m, s) 
If (h <= 0) And (m <= 0) And (s <= 0) Then 
Console.WriteLine("倒计时完毕，随意输入字符将退出程序：") 
Exit For 
End If 
End If 
End If 
Next 
Console.Read() 
End Sub 
End Module