[Rgen] Factory method that will generate the call of the GetHandle method.

src/rgen/Microsoft.Macios.Generator/Emitters/BindingSyntaxFactory.Runtime.cs

@@ -425,6 +425,21 @@ internal static InvocationExpressionSyntax SmartEnumGetValue (in TypeInfo enumTy
 		ImmutableArray<ArgumentSyntax> arguments)
 		=> SmartEnumGetValue (enumType, arguments, enumType.IsNullable);
 
+	/// <summary>
+	/// Generates the expression GetHandle () for a given expression syntax. For example:
+	/// NSArray.FromNSObjects(retval).GetHandle ();
+	/// </summary>
+	/// <param name="nativeObject"></param>
+	/// <returns></returns>
+	internal static InvocationExpressionSyntax GetHandle (ExpressionSyntax nativeObject)
+		=> InvocationExpression (
+			MemberAccessExpression (
+				SyntaxKind.SimpleMemberAccessExpression,
+				nativeObject,
+				IdentifierName ("GetHandle").WithTrailingTrivia (Space)
+			)
+		);
+
 	/// <summary>
 	/// Generate an object creation expressing for the given type info using the provided arguments.
 	/// </summary>

tests/rgen/Microsoft.Macios.Generator.Tests/Emitters/BindingSyntaxFactoryRuntimeTests.cs

@@ -437,6 +437,38 @@ void NSArrayFromNSObjectsTests (ImmutableArray<ArgumentSyntax> arguments, string
 		Assert.Equal (expectedDeclaration, declaration.ToFullString ());
 	}
 
+	class TestDataGetHandle : IEnumerable<object []> {
+		public IEnumerator<object []> GetEnumerator ()
+		{
+			yield return [
+				SmartEnumGetValue (
+					ReturnTypeForEnum ("AVFoundation.AVCaptureSystemPressureLevel", isSmartEnum: true),
+					[Argument (IdentifierName ("arg1"))],
+					false),
+				"global::AVFoundation.AVCaptureSystemPressureLevelExtensions.GetValue (arg1).GetHandle ()"
+			];
+
+			yield return [
+				SmartEnumGetValue (
+					ReturnTypeForEnum ("AVFoundation.AVCaptureSystemPressureLevel", isSmartEnum: true),
+					[Argument (IdentifierName ("arg1"))],
+					true),
+				"global::AVFoundation.AVCaptureSystemPressureLevelExtensions.GetNullableValue (arg1).GetHandle ()"
+			];
+		}
+
+		IEnumerator IEnumerable.GetEnumerator () => GetEnumerator ();
+	}
+
+	[Theory]
+	[ClassData (typeof (TestDataGetHandle))]
+	void GetHandleTests (ExpressionSyntax expression, string expectedDeclaration)
+	{
+		var declaration = GetHandle (expression);
+		Assert.Equal (expectedDeclaration, declaration.ToFullString ());
+	}
+
+
 	class TestDataNew : IEnumerable<object []> {
 		public IEnumerator<object []> GetEnumerator ()
 		{