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StringValidator Class

Provides validation of a string.

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

public class StringValidator : ConfigurationValidatorBase

The StringValidator type exposes the following members.

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.

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 a hash function for a particular type. (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).)

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.

using System;
using System.Configuration;

namespace Samples.AspNet
  class UsingStringValidator
    static void Main(string[] args)
      // Display title.
      Console.WriteLine("ASP.NET Validators");

      // Create string and validator.
      string testVal = "filename";
      StringValidator myStrValidator = new StringValidator(1,8,"$%^");

      // Determine if the object to validate can be validated.
      Console.WriteLine("CanValidate: {0}",

        // Attempt validation.
      catch (ArgumentException e)
        // Validation failed.
        Console.WriteLine("Error: {0}", e.Message.ToString());

      // Display and wait.

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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