Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Activities/System/Activities/Statements/ClearCollection.cs

@@ -0,0 +1,46 @@
+//-----------------------------------------------------------------------------
+// Copyright (c) Microsoft Corporation.  All rights reserved.
+//-----------------------------------------------------------------------------
+
+namespace System.Activities.Statements
+{
+    using System;
+    using System.Collections.Generic;
+    using System.ComponentModel;
+    using System.Windows.Markup;
+    using System.Diagnostics.CodeAnalysis;
+    using System.Runtime;
+    using System.Collections.ObjectModel;
+
+    [SuppressMessage(FxCop.Category.Naming, FxCop.Rule.IdentifiersShouldNotHaveIncorrectSuffix, Justification = "Optimizing for XAML naming.")]
+    [ContentProperty("Collection")]
+    public sealed class ClearCollection<T> : CodeActivity
+    {
+        [RequiredArgument]
+        [DefaultValue(null)]
+        public InArgument<ICollection<T>> Collection
+        {
+            get;
+            set;
+        }
+
+
+        protected override void CacheMetadata(CodeActivityMetadata metadata)
+        {
+            RuntimeArgument collectionArgument = new RuntimeArgument("Collection", typeof(ICollection<T>), ArgumentDirection.In, true);
+            metadata.Bind(this.Collection, collectionArgument);
+
+            metadata.SetArgumentsCollection(new Collection<RuntimeArgument> { collectionArgument });
+        }
+
+        protected override void Execute(CodeActivityContext context)
+        {
+            ICollection<T> collection = this.Collection.Get(context);
+            if (collection == null)
+            {
+                throw FxTrace.Exception.AsError(new InvalidOperationException(SR.CollectionActivityRequiresCollection(this.DisplayName)));
+            }
+            collection.Clear();
+        }
+    }
+}