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FeatureSupport Class

Provides static (Shared in Visual Basic) methods for retrieving feature information from the current system.

For a list of all members of this type, see FeatureSupport Members.

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

[Visual Basic]
MustInherit Public Class FeatureSupport
   Implements IFeatureSupport
[C#]
public abstract class FeatureSupport : IFeatureSupport
[C++]
public __gc __abstract class FeatureSupport : public
   IFeatureSupport
[JScript]
public abstract class FeatureSupport implements IFeatureSupport

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.

Remarks

Use the static (Shared in Visual Basic) 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.

Example

[Visual Basic, C#, C++] The following example uses the OSFeature implementation of FeatureSupport and queries for the LayeredWindows feature. The version is checked to see if it is a 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 Not (myVersion Is 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


[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 != 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.";
}


[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 != 0)
       textBox1->Text = S"Layered windows feature is installed.\n";
    else
       textBox1->Text = S"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, S"Again, layered windows feature is installed." );
    else
       textBox1->Text = String::Concat( textBox1->Text, S"Again, layered windows feature is not installed." );
 }
 

[JScript] No example is available for JScript. To view a Visual Basic, C#, or C++ example, click the Language Filter button Language Filter in the upper-left corner of the page.

Requirements

Namespace: System.Windows.Forms

Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family

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

See Also

FeatureSupport Members | System.Windows.Forms Namespace | OSFeature

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