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Writing Type Converters

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The Recipe Framework includes a number of library converter classes that you can use:

  • CodeIdentifierStringConverter. This class validates that the input value is a valid .NET identifier (for example, a valid method, property, or class name)
  • DteElementConverter. This class validates that the received value is a path expression that identifies an item in the logical tree view of the Solution Explorer, starting at the solution.
  • NamespaceStringConverter. This class validates that the input value is a valid namespace name.
  • ProjectConverter. This class validates that the input value is a path to a project, with the same rules as the DteElementConverter, but ensuring the target is always a project.
  • ProjectItemConverter. This class validates that the input value is a path to a project item, with the same rules as the DteElementConverter, but ensuring the target is always an item.
  • ReferenceConverter. This class validates that the input value is a path to a reference in a project.
  • RegexMatchStringConverter. This class validates that a string matches the pattern of a regular expression.
  • RegexNotMatchStringConverter. This class validates that a string does not match a pattern of a regular expression
  • SolutionConverter. This class validates that the input value is a reference to the root solution, that is, either a forward or a backward slash.
  • SolutionFolderConverter. This class validates that the input value is a path to a solution folder, with the same rules as the DteElementConverter, but ensuring the target is always a solution folder.

You may also want to write your own type converter. To define a type converter, you need to derive from the TypeConverter class, as shown in the following code example.

using System;
using System.ComponentModel;

namespace $PackageNamespace$.Converters
{
  /// <summary>
  /// Sample converter that returns a list of optional values to pick from, but 
  /// validates that the value entered starts with "Hello ".
  /// </summary>
  public class HelloWorldConverter : TypeConverter
  {
    static string[] validValues = new string[] {
    "Hello Guidance Automation Toolkit!", "Hello Microsoft!", "Hello World!" };

    public override bool IsValid(ITypeDescriptorContext context, object value)
    {
      return (value is string && ((string)value).StartsWith("Hello "));
    }

    public override bool GetStandardValuesExclusive(ITypeDescriptorContext context)
    {
      return false;
    }

    public override bool GetStandardValuesSupported(ITypeDescriptorContext context)
    {
      return true;
    }

    public override StandardValuesCollection GetStandardValues(ITypeDescriptorContext context)
    {
      return new StandardValuesCollection(validValues);
    }
  }
}

Note

A type converter may use services from other components, including Visual Studio itself. For more information, see Obtaining and Using Host Services.

See also

Developing Wizards | Defining a Wizard | Defining a User Interface Value Editor | Writing a Custom Wizard Page | Implementing Argument Value Propagation