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
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