原文地址：http://www.dotnetperls.com/regex-match-vbnet
Shared.
A Regex object requires time to be created. We can instead share Regex objects,with the shared keyword. A shared Regex object is faster than shared Regex Functions.
共享方法。
一个正则表达式对象需要时间去创造。我们可以用Shared关键字分享regex对象。共享Regex对象的速度比共享的正则表达式方法的速度快。
Therefore:
Storing a Regex as a field in a module or class often results in a speed boost,when Match is called more than once.
因此：
当不止一次调用Match方法时，存储一个正则表达式作为一个模块或类可以加快速度。
Function:
The Match function is an instance function on a Regex object. This program has the same result as the prevIoUs program.
功能：
Match方法变为一个正则表达式实例化后的一个方法。这个程序与以前的程序相同。
下面是代码：
例四：Shared. 方法
VB.NET program that uses Match on Regex field
Imports System.Text.RegularExpressions
Module Module1
@H_403_53@ ''' <summary>
''' Member field regular expression.
''' </summary>
Private _reg As Regex = New Regex("content/([A-Za-z0-9\-]+)\.aspx$",_
RegexOptions.IgnoreCase)
Sub Main()
@H_403_53@' The input string.
Dim value As String = "/content/alternate-1.aspx"
@H_403_53@' Invoke the Match method.
' ... Use the regex field.
Dim m As Match = _reg.Match(value)
@H_403_53@' If successful,write the group.
If (m.Success) Then
Dim key As String = m.Groups(1).Value
Console.WriteLine(key)
End If
End Sub
End Module
Output
alternate-1
就是把原来的 Regex.Match方法改为new一个Regex_reg As Regex = New Regex("content/([A-Za-z0-9\-]+)\.aspx$",_
RegexOptions.IgnoreCase)
The Match() Function returns the first match only. But we can call NextMatch() on that returned Match object. This is a match that is found in the text,further on.
Match,NextMatch.方法。
Match方法只会返回第一个匹配值，但我们可以使用NextMatch方法在第一个匹配的返回值中再次匹配。这是一个进一步在文本中找到的匹配项的方法。
Tip:
NextMatch can be called in a loop. This results in behavior similar to the Matches method (which may be easier to use).
提示：
可以在循环中调用NextMatch。此结果在行为类似于匹配方法（可能更容易使用）。
下面是代码：
例五：NextMatch
VB.NET program that uses Match,NextMatch
Imports System.Text.RegularExpressions
Module Module1
Sub Main()
@H_403_53@' Get first match.
Dim match As Match = Regex.Match("4 and 5","\d")
If match.Success Then
Console.WriteLine(match.Value)
End If
@H_403_53@' Get next match.
match = match.NextMatch()
If match.Success Then
Console.WriteLine(match.Value)
End If
End Sub
End Module
Output
4
5
先匹配到4，再匹配到5
IsMatch.
This returns true if a String matches the regular expression. We get a Boolean that tells us whether a pattern matches. If no other results are needed,IsMatch is useful.
表示是否匹配的布尔值
如果正则表达式与字符串相匹配则返回true.我们用一个布尔值判断标识符是否匹配。如果没有其他需要的结果，IsMatch 就是有用的。
Here:
This program introduces the IsValid Boolean function,which computes the result of the Regex.IsMatch function on its parameter.
Note:
The regular expression pattern indicates any string of lowercase ASCII letters,uppercase ASCII letters,or digits.
在这里
这个函数介绍了有效的布尔函数，计算的结果regex.ismatch功能参数。
注意：
正则表达式模式表示任何字符串的小写字母，大写字母，或数字。
下面是代码：
例六：IsMatch.
VB.NET program that uses Regex.IsMatch function
Imports System.Text.RegularExpressions
Module Module1
Function IsValid(ByRef value As String) As Boolean
Return @H_403_53@Regex.IsMatch(value,"^[a-zA-Z0-9]*$")
End Function
Sub Main()
Console.WriteLine(IsValid("dotnetperls0123"))
Console.WriteLine(IsValid("DotNetPerls"))
Console.WriteLine(IsValid(":-)"))
End Sub
End Module
Output
True
True
False
[a-zA-Z0-9]意思是范围包括小写字母a至z；大写字母A至Z；数字0至9
原文链接：https://www.f2er.com/regex/359978.html