StringValidator Class

Definition

Namespace:

System.Configuration

Assembly:

System.Configuration.ConfigurationManager.dll

Provides validation of a string.

public ref class StringValidator : System::Configuration::ConfigurationValidatorBase

public class StringValidator : System.Configuration.ConfigurationValidatorBase

type StringValidator = class
    inherit ConfigurationValidatorBase

Public Class StringValidator
Inherits ConfigurationValidatorBase

Inheritance

Object

ConfigurationValidatorBase

StringValidator

Examples

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");
      Console.WriteLine();

      // 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}",
        myStrValidator.CanValidate(testVal.GetType()));

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

      // Display and wait.
      Console.ReadLine();
    }
  }
}

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

Remarks

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.

Constructors

StringValidator(Int32, Int32, String)	Initializes a new instance of the StringValidator class, based on supplied parameters.
StringValidator(Int32, Int32)	Initializes a new instance of the StringValidator class, based on supplied parameters.
StringValidator(Int32)	Initializes a new instance of the StringValidator class, based on a supplied parameter.

Methods

CanValidate(Type)	Determines whether an object can be validated based on type.
Equals(Object)	Determines whether the specified object is equal to the current object. (Inherited from Object)
GetHashCode()	Serves as the default hash function. (Inherited from Object)
GetType()	Gets the Type of the current instance. (Inherited from Object)
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
ToString()	Returns a string that represents the current object. (Inherited from Object)
Validate(Object)	Determines whether the value of an object is valid.

See also

• StringValidatorAttribute
• ConfigurationValidatorBase