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StringValidator Class

Provides validation of a string.

Namespace:  System.Configuration
Assembly:  System.Configuration (in System.Configuration.dll)

'Declaration
Public Class StringValidator _
	Inherits ConfigurationValidatorBase

The StringValidator type exposes the following members.

  NameDescription
Public methodStringValidator(Int32)Initializes a new instance of the StringValidator class, based on a supplied parameter.
Public methodStringValidator(Int32, Int32)Initializes a new instance of the StringValidator class, based on supplied parameters.
Public methodStringValidator(Int32, Int32, String)Initializes a new instance of the StringValidator class, based on supplied parameters.
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  NameDescription
Public methodCanValidateDetermines whether an object can be validated based on type. (Overrides ConfigurationValidatorBase.CanValidate(Type).)
Public methodEquals(Object)Determines whether the specified object is equal to the current object. (Inherited from Object.)
Protected methodFinalizeAllows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public methodGetHashCodeServes as the default hash function. (Inherited from Object.)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Protected methodMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Public methodToStringReturns a string that represents the current object. (Inherited from Object.)
Public methodValidateDetermines whether the value of an object is valid. (Overrides ConfigurationValidatorBase.Validate(Object).)
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The StringValidator class is used to ensure that a string meets specific criteria. The criteria for validation is established when an instance of the StringValidator class is created. There are three constructor overloads for the StringValidator class. The StringValidator.StringValidator(Int32) constructor with one parameter verifies the minimum acceptable length of the string being validated. The StringValidator.StringValidator(Int32, Int32) constructor with two parameters ensures that the string being verified adheres to both a minimum and a maximum length. The StringValidator.StringValidator(Int32, Int32, String) constructor with three parameters checks both the minimum and the maximum length values of the string being verified, as well as whether specific characters are present in the string being validated.

The CanValidate method determines whether the object type being validated matches the expected type. The object being validated is passed as a parameter of the Validate method.

The following example demonstrates how to use the StringValidator type.

Imports System
Imports System.Configuration

Namespace Samples.AspNet
  Class UsingStringValidator
    Public Shared Sub Main()

      ' Display title.
      Console.WriteLine("ASP.NET Validators")
      Console.WriteLine()

      ' Create string and validator. 
      Dim testVal As String = "filename" 
      Dim myStrValidator As StringValidator = New StringValidator(1, 8, "$%^")

      ' Determine if the object to validate can be validated.
      Console.WriteLine("CanValidate: {0}", _
        myStrValidator.CanValidate(testVal.GetType()))

      Try 
        ' Attempt validation.
        myStrValidator.Validate(testVal)
        Console.WriteLine("Validated.")

      Catch e As Exception
        ' Validation failed.
        Console.WriteLine("Error: {0}", e.Message.ToString())
      End Try 

      ' Display and wait.
      Console.ReadLine()
    End Sub 
  End Class 
End Namespace

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
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