Port ColumnHeaderCollectionEditor

src/System.Design/src/System.Design.Forwards.cs

@@ -3,7 +3,7 @@
 // See the LICENSE file in the project root for more information.
 
 using System.Runtime.CompilerServices;
-
+[assembly: TypeForwardedTo(typeof(System.Windows.Forms.Design.ColumnHeaderCollectionEditor))]
 [assembly: TypeForwardedTo(typeof(System.Windows.Forms.Design.DataMemberFieldConverter))]
 [assembly: TypeForwardedTo(typeof(System.Windows.Forms.Design.FormatStringEditor))]
 [assembly: TypeForwardedTo(typeof(System.Windows.Forms.Design.HelpNamespaceEditor))]

src/System.Windows.Forms.Design.Editors/src/System/Windows/Forms/Design/ColumnHeaderCollectionEditor.cs

@@ -0,0 +1,70 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.ComponentModel;
+using System.ComponentModel.Design;
+
+namespace System.Windows.Forms.Design
+{
+    internal class ColumnHeaderCollectionEditor : CollectionEditor
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref='System.Windows.Forms.Design.ImageCollectionEditor'/> class.
+        /// </summary>
+        public ColumnHeaderCollectionEditor(Type type) : base(type)
+        {
+        }
+
+        /// <summary>
+        /// Gets the help topic to display for the dialog help button or pressing F1. Override to display a different help topic.
+        /// </summary>
+        protected override string HelpTopic
+        {
+            get => "net.ComponentModel.ColumnHeaderCollectionEditor";
+        }
+
+        /// <summary>
+        /// Sets the specified collection to have the specified array of items.
+        /// </summary>
+        protected override object SetItems(object editValue, object[] value)
+        {
+            if (editValue is ListView.ColumnHeaderCollection list)
+            {
+                list.Clear();
+                ColumnHeader[] colHeaders = new ColumnHeader[value.Length];
+                Array.Copy(value, 0, colHeaders, 0, value.Length);
+                list.AddRange(colHeaders);
+            }
+            return editValue;
+        }
+
+        /// <summary>
+        /// Removes the item from listview column header collection
+        /// </summary>
+        internal override void OnItemRemoving(object item)
+        {
+            if (!(Context.Instance is ListView listview))
+            {
+                return;
+            }
+
+            if (item is ColumnHeader column)
+            {
+                IComponentChangeService cs = GetService(typeof(IComponentChangeService)) as IComponentChangeService;
+                PropertyDescriptor itemsProp = null;
+                if (cs != null)
+                {
+                    itemsProp = TypeDescriptor.GetProperties(Context.Instance)["Columns"];
+                    cs.OnComponentChanging(Context.Instance, itemsProp);
+                }
+                listview.Columns.Remove(column);
+
+                if (cs != null && itemsProp != null)
+                {
+                    cs.OnComponentChanged(Context.Instance, itemsProp, null, null);
+                }
+            }
+        }
+    }
+}

src/System.Windows.Forms.Design.Editors/tests/UnitTests/System/Windows/Forms/Design/ColumnHeaderCollectionEditorTests .cs

@@ -0,0 +1,27 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using Xunit;
+
+namespace System.Windows.Forms.Design.Tests
+{
+    public class ColumnHeaderCollectionEditorTests
+    {
+        [Fact]
+        public void ColumnHeaderCollectionEditor_Ctor_Default()
+        {
+            var editor = new ColumnHeaderCollectionEditor(typeof(string));
+            Assert.False(editor.IsDropDownResizable);
+        }
+
+        [Fact]
+        public void ColumnHeaderCollectionEditor_EditValue_ReturnsValue()
+        {
+            var editor = new ColumnHeaderCollectionEditor(typeof(string));
+            string[] value = new string[] { "asdf", "qwer", "zxcv" };
+
+            Assert.Same(value, editor.EditValue(null, value));
+        }
+    }
+}