StringValidator Class


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Provides validation of a string.

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


public class StringValidator : ConfigurationValidatorBase


Initializes a new instance of the StringValidator class, based on a supplied parameter.

System_CAPS_pubmethodStringValidator(Int32, Int32)

Initializes a new instance of the StringValidator class, based on supplied parameters.

System_CAPS_pubmethodStringValidator(Int32, Int32, String)

Initializes a new instance of the StringValidator class, based on supplied parameters.


Determines whether an object can be validated based on type.(Overrides ConfigurationValidatorBase.CanValidate(Type).)


Determines whether the specified object is equal to the current object.(Inherited from Object.)


Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.(Inherited from Object.)


Serves as the default hash function. (Inherited from Object.)


Gets the Type of the current instance.(Inherited from Object.)


Creates a shallow copy of the current Object.(Inherited from Object.)


Returns a string that represents the current object.(Inherited from Object.)


Determines 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
Available since 2.0

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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