Replace Method (String, MatchEvaluator, Int32, Int32)

Regex.Replace Method (String, MatchEvaluator, Int32, Int32)

[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]

Within a specified input substring, replaces a specified maximum number of strings that match a regular expression pattern with a string returned by a MatchEvaluator delegate.

Namespace:  System.Text.RegularExpressions
Assembly:  System (in System.dll)

'Declaration
Public Function Replace ( _
	input As String, _
	evaluator As MatchEvaluator, _
	count As Integer, _
	startat As Integer _
) As String

Parameters

input
Type: System.String
The string to search for a match.
evaluator
Type: System.Text.RegularExpressions.MatchEvaluator
A custom method that examines each match and returns either the original matched string or a replacement string.
count
Type: System.Int32
The maximum number of times the replacement will occur.
startat
Type: System.Int32
The character position in the input string where the search begins.

Return Value

Type: System.String
A new string that is identical to the input string, except that a replacement string takes the place of each matched string.

ExceptionCondition
ArgumentNullException

input is Nothing.

-or-

evaluator is Nothing.

ArgumentOutOfRangeException

startat is less than zero or greater than the length of input.

The Regex.Replace method is useful for replacing a regular expression match if any of the following conditions is true:

  • The replacement string cannot readily be specified by a regular expression replacement pattern.

  • The replacement string results from some processing done on the matched string.

  • The replacement string results from conditional processing.

The method is equivalent to calling the Regex.Matches method and passing the first countMatch objects in the returned MatchCollection collection to the evaluator delegate.

The regular expression is the pattern defined by the constructor for the current Regex object.

The evaluator parameter is the delegate for a custom method that you define and that examines each match. The custom method must have the following signature to match the MatchEvaluator delegate.


Public Function MatchEvaluatorMethod(ByVal match As Match) As String


Your custom method returns a string that replaces the matched input.

Windows Phone OS

Supported in: 8.1, 8.0, 7.1, 7.0

Windows Phone

Show:
© 2017 Microsoft