FeatureSupport Class (System.Windows.Forms)

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Microsoft Visual Studio 2008/.NET Framework 3.5

Other versions are also available for the following:

.NET Framework Class Library

FeatureSupport Class

Provides static methods for retrieving feature information from the current system.

Namespace: System.Windows.Forms
Assembly: System.Windows.Forms (in System.Windows.Forms.dll)

Syntax

Visual Basic (Declaration)

Public MustInherit Class FeatureSupport _
    Implements IFeatureSupport

Visual Basic (Usage)

Dim instance As FeatureSupport

public abstract class FeatureSupport : IFeatureSupport

Visual C++

public ref class FeatureSupport abstract : IFeatureSupport

JScript

public abstract class FeatureSupport implements IFeatureSupport

Remarks

Use the static methods of this class when the classes you query for feature information implement the IFeatureSupport interface. Otherwise, inherit from FeatureSupport and provide your own implementation. For an implementation of this class, see OSFeature.

To get the version number of a feature, call GetVersionPresent. Call IsPresent to determine if a particular feature or version of a feature is installed.

Notes to Inheritors:

When you inherit from FeatureSupport, you must override the GetVersionPresent method. When you override this method, check that the class that you use for the feature parameter is the same as the class used for this parameter in the IsPresent method. If the two feature parameters differ, you also must override IsPresent.

Examples

The following example uses the OSFeature implementation of FeatureSupport and queries for the LayeredWindows feature. The version is checked to see if it is nullNothingnullptra null reference (Nothing in Visual Basic), to determine whether the feature is present. The result is displayed in a text box. This code assumes textBox1 has been created and placed on a form.

Visual Basic

Private Sub LayeredWindows()
    ' Gets the version of the layered windows feature.
    Dim myVersion As Version = _
       OSFeature.Feature.GetVersionPresent(OSFeature.LayeredWindows)

    ' Prints whether the feature is available.
    If (myVersion IsNot Nothing) Then
        textBox1.Text = "Layered windows feature is installed." & _
           ControlChars.CrLf
    Else
        textBox1.Text = "Layered windows feature is not installed." & _
           ControlChars.CrLf
    End If 
    'This is an alternate way to check whether a feature is present.
    If OSFeature.Feature.IsPresent(OSFeature.LayeredWindows) Then
        textBox1.Text &= "Again, layered windows feature is installed."
    Else
        textBox1.Text &= "Again, layered windows feature is not installed."
    End If
End Sub

private void LayeredWindows() {
   // Gets the version of the layered windows feature.
   Version myVersion = OSFeature.Feature.GetVersionPresent(OSFeature.LayeredWindows);

   // Prints whether the feature is available.
   if (myVersion != null)
      textBox1.Text = "Layered windows feature is installed." + '\n';
   else
      textBox1.Text = "Layered windows feature is not installed." + '\n';

   // This is an alternate way to check whether a feature is present.
   if (OSFeature.Feature.IsPresent(OSFeature.LayeredWindows))
      textBox1.Text += "Again, layered windows feature is installed.";
   else
      textBox1.Text += "Again, layered windows feature is not installed.";
}

Visual C++

private:
   void LayeredWindows()
   {
      // Gets the version of the layered windows feature.
      Version^ myVersion = OSFeature::Feature->GetVersionPresent(
         OSFeature::LayeredWindows );

      // Prints whether the feature is available.
      if ( myVersion != nullptr )
      {
         textBox1->Text = "Layered windows feature is installed.\n";
      }
      else
      {
         textBox1->Text = "Layered windows feature is not installed.\n";
      }


      // This is an alternate way to check whether a feature is present.
      if ( OSFeature::Feature->IsPresent( OSFeature::LayeredWindows ) )
      {
         textBox1->Text = String::Concat( textBox1->Text,
            "Again, layered windows feature is installed." );
      }
      else
      {
         textBox1->Text = String::Concat( textBox1->Text,
            "Again, layered windows feature is not installed." );
      }
   }

Inheritance Hierarchy

System..::.Object
System.Windows.Forms..::.FeatureSupport
System.Windows.Forms..::.OSFeature

Thread Safety

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

Platforms

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

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

Version Information

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0

Reference

FeatureSupport Members

System.Windows.Forms Namespace

OSFeature