Const n = 234234245#

标题中的这个常量申明，不是会VB的人可能会不知道，比如--我。
查了半天搞明白啦，原来是强制转换为double啊~~

Msdn上查到的，还是贴出来，省得ms变地址得时候找不到。

The following example demonstrates correct usage of type characters and enclosing characters:

Option Strict Off
Public Const DefaultInteger = 100   ' Default is Integer.
Public Const DefaultDouble = 54.3345612   ' Default is Double.
Public Const MyCharacter = "a"C   ' Forces constant to be a Char type.
Public Const MyDate = #01/15/01#   ' Demonstrates DateTime constants.
Public Const MyTime = #1:15:59 AM#
Public Const MyLong = 45L   ' Forces data type to be a Long.
Public Const MySingle = 45.55!   ' Forces data type to be a Single.

The following table shows the enclosing characters and type characters available in Visual Basic.

Data type	Enclosing character	Appended type character
Boolean	(none)	(none)
Byte	(none)	(none)
Char	"	C
Date	#	(none)
Decimal	(none)	D or @
Double	(none)	R or #
Integer	(none)	I or %
Long	(none)	L or &
Short	(none)	S
Single	(none)	F or !
String	"	(none)