FeatureSupport.IsPresent Method

Definition

Namespace:

System.Windows.Forms

Assembly:

System.Windows.Forms.dll

Determines whether the specified feature is installed in the system.

Overloads

IsPresent(Object)	Determines whether any version of the specified feature is installed in the system.
IsPresent(Object, Version)	Determines whether the specified or newer version of the specified feature is installed in the system.
IsPresent(String, String)	Determines whether any version of the specified feature is installed in the system. This method is static.
IsPresent(String, String, Version)	Determines whether the specified or newer version of the specified feature is installed in the system. This method is static.

IsPresent(Object)

Source:

FeatureSupport.cs

Determines whether any version of the specified feature is installed in the system.

public:
 virtual bool IsPresent(System::Object ^ feature);

public virtual bool IsPresent (object feature);

abstract member IsPresent : obj -> bool
override this.IsPresent : obj -> bool

Public Overridable Function IsPresent (feature As Object) As Boolean

Parameters

feature

Object

The feature to look for.

Returns

Boolean

true if the feature is present; otherwise, false.

Implements

IsPresent(Object)

Examples

The following code example uses the OSFeature implementation of FeatureSupport and queries for the LayeredWindows feature. The version is checked to see if it is null, to determine whether the feature is present. The result is displayed in a text box. This code requires that textBox1 has been created and placed on a form.

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." );
      }
   }

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.";
}

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

Notes to Inheritors

When you inherit from FeatureSupport, you must override the GetVersionPresent(String, String) 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(String, String) method. If the two feature parameters differ, you must also override IsPresent(String, String).

IsPresent(Object, Version)

Source:

FeatureSupport.cs

Determines whether the specified or newer version of the specified feature is installed in the system.

public:
 virtual bool IsPresent(System::Object ^ feature, Version ^ minimumVersion);

public virtual bool IsPresent (object feature, Version minimumVersion);

abstract member IsPresent : obj * Version -> bool
override this.IsPresent : obj * Version -> bool

Public Overridable Function IsPresent (feature As Object, minimumVersion As Version) As Boolean

Parameters

feature

Object

The feature to look for.

minimumVersion

Version

A Version representing the minimum version number of the feature to look for.

Returns

Boolean

true if the feature is present and its version number is greater than or equal to the specified minimum version number; false if the feature is not installed or its version number is below the specified minimum number.

Implements

IsPresent(Object, Version)

Notes to Inheritors

When you inherit from FeatureSupport, you must override the GetVersionPresent(String, String) 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(String, String) method. If the two feature parameters differ, you must also override IsPresent(String, String).

IsPresent(String, String)

Source:

FeatureSupport.cs

Determines whether any version of the specified feature is installed in the system. This method is static.

public:
 static bool IsPresent(System::String ^ featureClassName, System::String ^ featureConstName);

public static bool IsPresent (string featureClassName, string featureConstName);

static member IsPresent : string * string -> bool

Public Shared Function IsPresent (featureClassName As String, featureConstName As String) As Boolean

Parameters

featureClassName

String

The fully qualified name of the class to query for information about the specified feature. This class must implement the IFeatureSupport interface or inherit from a class that implements this interface.

featureConstName

String

The fully qualified name of the feature to look for.

Returns

Boolean

true if the specified feature is present; false if the specified feature is not present or if the product containing the feature is not installed.

Remarks

See the documentation for the product containing the feature to determine the names to pass to the featureClassName and the featureConstName parameters.

See also

• GetVersionPresent(String, String)

IsPresent(String, String, Version)

Source:

FeatureSupport.cs

Determines whether the specified or newer version of the specified feature is installed in the system. This method is static.

public:
 static bool IsPresent(System::String ^ featureClassName, System::String ^ featureConstName, Version ^ minimumVersion);

public static bool IsPresent (string featureClassName, string featureConstName, Version minimumVersion);

static member IsPresent : string * string * Version -> bool

Public Shared Function IsPresent (featureClassName As String, featureConstName As String, minimumVersion As Version) As Boolean

Parameters

featureClassName

String

The fully qualified name of the class to query for information about the specified feature. This class must implement the IFeatureSupport interface or inherit from a class that implements this interface.

featureConstName

String

The fully qualified name of the feature to look for.

minimumVersion

Version

A Version representing the minimum version number of the feature.

Returns

Boolean

true if the feature is present and its version number is greater than or equal to the specified minimum version number; false if the feature is not installed or its version number is below the specified minimum number.

Remarks

See the documentation for the product containing the feature to determine the names to pass to the featureClassName and the featureConstName parameters.

See also

• GetVersionPresent(String, String)