txt文件中如何判断句尾是不是" "

txt文件中怎么判断句尾是不是" "?
vb.net 2003

比如说,strings.Instr 方法来可以做比较....

Public Shared Function InStr(_
  Optional ByVal Start As Integer, _
  ByVal String1 As String, _
  ByVal String2 As String, _
) As Integer

Start 
可选项。数值表达式，设置每个搜索的起始位置。如果省略该参数，则从第一个字符位置开始搜索。起始索引从一开始。 

它是从起始位置开始搜索...


我想实现的是判断一行句子中的句尾是不是" ", 有什么办法像上面的方法一样能做比较...

需要详细代码以及详细说明...

[解决办法]
\s$
[解决办法]
"ABC " has 4 characters. "ABC ".length is 4

"ABC" has 3 characters. "ABC".length is 3.

"ABC ".rtrim() is to remove all right spaces.

sample code:

VB.NET code

Dim aString as StringaString = "ABC  "if aString.rtrim().length = aString.length then msgbox "The string has no space at the end."else dim numSpace as String numSpace  = aString.length  - aString.rtrim().length  msgbox "The string has " & numSpace   & " spaces at the end."end if
[解决办法]
Dim re As New Regex("^.* $", RegexOptions.Multiline)  
Dim oldstr As String = Read_Txt()  
oldstr = Regex.Replace(oldstr, "\r\n", vbLf)  
Dim match As Match = re.Match(oldstr)  
match = re.Match(oldstr)  
While match.Success  
   Console.WriteLine(match.Value)  
  
   match = match.NextMatch()  
End While