Enable nullable reference types for System.Windows.Forms.Design

[elachlan]

Is your feature request related to a problem? Please describe

System.Windows.Forms.Design does not have <Nullable>enable</Nullable> in its project file and the individual files aren't marked to enable/disable NRTs.

I am creating this issue to help track the progress

I suggest the following plan which has been implemented previously with other projects:

1. Enable Nullable in the project file and marking each file with #nullable disable where needed.
2. Community/team PRs to slowly enable nullability in the code base.

Related: #1107

List of files which need annotating ordered by line count ascending:

\src\System\Drawing\Design\IToolboxItemProvider.cs	11
\src\System\Windows\Forms\Design\ServiceProviderExtensions.cs	12
\src\System\ComponentModel\Design\DesignerActionTextItem.cs	13
\src\System\Windows\Forms\Design\IContainsThemedScrollbarWindows.cs	15
\src\System\ComponentModel\Design\DesignerActionHeaderItem.cs	16
\src\System\ComponentModel\Design\DesignerCommandSet.cs	16
\src\System\ComponentModel\Design\ProjectTargetFrameworkAttribute.cs	16
\src\System\ComponentModel\Design\IMultitargetHelperService.cs	17
\src\System\Drawing\Design\MetafileEditor.cs	18
\src\System\Drawing\Design\BitmapEditor.cs	19
\src\System\Windows\Forms\Design\Behavior\BehaviorDragDropEventArgs.cs	19
\src\System\ComponentModel\Design\HostDesigntimeLicenseContext.cs	20
\src\System\ComponentModel\Design\Serialization\MemberCodeDomSerializer.cs	21
\src\System\Windows\Forms\Design\ContextMenuStripGroup.cs	21
\src\System\ComponentModel\Design\DesignerActionItemCollection.cs	22
\src\System\ComponentModel\Design\DesignerActionPanel.DesignerActionPanelHeaderItem.cs	22
\src\System\ComponentModel\Design\DesignerActionPropertyItem.cs	22
\src\System\ComponentModel\Design\ExceptionCollection.cs	22
\src\System\ComponentModel\Design\ObjectSelectorEditor.SelectorNode.cs	22
\src\System\Drawing\Design\ColorEditor.SystemColorComparer.cs	22
\src\System\Drawing\Design\IToolboxUser.cs	22
\src\System\Runtime\InteropServices\UCOMITypeLib.cs	24
\src\System\ComponentModel\Design\Serialization\ICodeDomDesignerReload.cs	25
\src\System\Windows\Forms\Design\DataMemberFieldConverter.cs	26
\src\System\Drawing\Design\ToolboxComponentsCreatedEventArgs.cs	27
\src\System\Drawing\Design\ToolboxComponentsCreatingEventArgs.cs	27
\src\System\Windows\Forms\Design\ControlDesigner.CanResetSizePropertyDescriptor.cs	27
\src\System\Windows\Forms\Design\RadioButtonDesigner.cs	27
\src\System\ComponentModel\Design\ActiveDesignSurfaceChangedEventArgs.cs	29
\src\System\ComponentModel\Design\DesignerActionUIStateChangeEventArgs.cs	29
\src\System\ComponentModel\Design\DesignSurfaceEvent.cs	29
\src\System\Windows\Forms\Design\ListControlStringCollectionEditor.cs	29
\src\System\ComponentModel\Design\LoadedEventArgs.cs	30
\src\System\Windows\Forms\Design\AnchorEditor.cs	32
\src\System\Windows\Forms\Design\TextBoxActionList.cs	32
\src\System\Windows\Forms\Design\WindowsFormsDesignerOptionService.cs	32
\src\System\ComponentModel\Design\DateTimeEditor.cs	33
\src\System\ComponentModel\Design\DesignerActionItem.cs	33
\src\System\Windows\Forms\Design\DockEditor.cs	33
\src\System\ComponentModel\Design\Serialization\RootContext.cs	35
\src\System\Drawing\Design\ContentAlignmentEditor.cs	35
\src\System\Drawing\Design\CursorEditor.cs	36
\src\System\Windows\Forms\Design\BorderSidesEditor.cs	36
\src\System\Windows\Forms\Design\TabPageCollectionEditor.cs	36
\src\System\ComponentModel\Design\MultilineStringEditor.cs	37
\src\System\Resources\Tools\ITargetAwareCodeDomProvider.cs	38
\src\System\Windows\Forms\Design\ToolStripCodeDomSerializer.cs	38
\src\System\ComponentModel\Design\Serialization\CodeDomSerializerException.cs	39
\src\System\Windows\Forms\Design\FolderNameEditor.cs	39
\src\System\Windows\Forms\Design\PictureBoxActionList.cs	39
\src\System\Windows\Forms\Design\TreeViewActionList.cs	39
\src\System\ComponentModel\Design\DesignerActionPanel.TypeDescriptorContext.cs	40
\src\System\ComponentModel\Design\Serialization\ExpressionTable.cs	41
\src\System\Windows\Forms\Design\ShortcutKeysEditor.cs	42
\src\System\ComponentModel\Design\CollectionEditor.PropertyGridSite.cs	44
\src\System\Windows\Forms\Design\DataGridViewCellStyleEditor.cs	44
\src\System\Windows\Forms\Design\DesignBindingValueUIHandler.LocalUIItem.cs	44
\src\System\Windows\Forms\Design\ListViewItemCollectionEditor.cs	44
\src\System\ComponentModel\Design\DesignerActionListsChangedEventArgs.cs	45
\src\System\Windows\Forms\Design\ContextMenuStripGroupCollection.cs	45
\src\System\Windows\Forms\Design\Behavior\BehaviorService.MenuCommandHandler.cs	46
\src\System\Windows\Forms\Design\StringArrayEditor.cs	46
\src\System\Drawing\Design\ColorEditor.ColorPalette.ColorPaletteAccessibleObject.cs	47
\src\System\Windows\Forms\Design\ImageListImage.cs	47
\src\System\ComponentModel\Design\Serialization\SerializeAbsoluteContext.cs	48
\src\System\ComponentModel\Design\DesignSurfaceServiceContainer.cs	48
\src\System\Windows\Forms\Design\Behavior\BehaviorServiceAdornerCollectionEnumerator.cs	48
\src\System\Windows\Forms\Design\MaskedTextBoxTextEditor.cs	49
\src\System\ComponentModel\Design\Serialization\CodeDomLocalizationProvider.LanguageCultureInfoConverter.cs	50
\src\System\ComponentModel\Design\DesignerActionListCollection.cs	50
\src\System\Drawing\Design\ColorEditor.cs	50
\src\System\Windows\Forms\Design\DesignerExtenders.cs	50
\src\System\Windows\Forms\Design\DesignerExtenders.NameInheritedExtenderProvider.cs	50
\src\System\Windows\Forms\Design\DataGridViewComponentPropertyGridSite.cs	51
\src\System\Windows\Forms\Design\DataGridViewRowCollectionCodeDomSerializer.cs	51
\src\System\Windows\Forms\Design\FileNameEditor.cs	51
\src\System\Windows\Forms\Design\ToolStripMenuItemCodeDomSerializer.cs	52
\src\System\ComponentModel\Design\ExtenderProviderService.cs	53
\src\System\Drawing\Design\FontEditor.cs	53
\src\System\Windows\Forms\Design\Behavior\DesignerActionKeyboardBehavior.cs	53
\src\System\ComponentModel\Design\DesignerActionMethodItem.cs	54
\src\System\ComponentModel\Design\ArrayEditor.cs	55
\src\System\Drawing\Design\ColorEditor.StandardColorComparer.cs	55
\src\System\ComponentModel\Design\Serialization\PrimitiveCodeDomSerializer.cs	56
\src\System\Windows\Forms\Design\LinkAreaEditor.cs	57
\src\System\Windows\Forms\Design\ParentControlDesigner.EscapeHandler.cs	57
\src\System\Windows\Forms\Design\ControlDesigner.DesignerControlCollection.cs	58
\src\System\Windows\Forms\Design\SelectionUIService.HitTestInfo.cs	58
\src\System\ComponentModel\Design\DesignerActionPanel.CheckBoxPropertyLine.cs	59
\src\System\Windows\Forms\Design\ItemTypeToolStripMenuItem.cs	59
\src\System\Windows\Forms\Design\MaskedTextBoxDesignerActionList.cs	59
\src\System\Windows\Forms\Design\Behavior\Glyph.cs	60
\src\System\Windows\Forms\Design\ControlDesigner.DockingActionList.cs	61
\src\System\Windows\Forms\Design\ListViewGroupCollectionEditor.cs	61
\src\System\Drawing\Design\ToolboxItemCollection.cs	62
\src\System\Windows\Forms\Design\ToolStripItemGlyph.cs	62
\src\System\ComponentModel\Design\DesignerActionPanel.Line.cs	63
\src\System\Windows\Forms\Design\UpDownBaseDesigner.cs	63
\src\System\Windows\Forms\Design\ColumnHeaderCollectionEditor.cs	64
\src\System\Windows\Forms\Design\ScrollableControlDesigner.cs	64
\src\System\Windows\Forms\Design\DesignerToolStripControlHost.cs	65
\src\System\ComponentModel\Design\Serialization\ExpressionContext.cs	66
\src\System\Windows\Forms\Design\DesignBindingValueUIHandler.cs	66
\src\System\Windows\Forms\Design\UserControlDocumentDesigner.cs	66
\src\System\Windows\Forms\Design\ControlDesigner.ChildSubClass.cs	67
\src\System\ComponentModel\Design\ObjectSelectorEditor.cs	70
\src\System\Windows\Forms\Design\ControlDesigner.DesignerWindowTarget.cs	70
\src\System\ComponentModel\Design\DesignerActionPanel.TextLine.cs	71
\src\System\Windows\Forms\Design\NewItemsContextMenuStrip.cs	71
\src\System\ComponentModel\Design\Serialization\ComponentTypeCodeDomSerializer.cs	72
\src\System\ComponentModel\Design\ComponentDesigner.ShadowPropertyCollection.cs	72
\src\System\Windows\Forms\Design\TableLayoutPanelCodeDomSerializer.cs	73
\src\System\Windows\Forms\Design\TreeViewDesigner.cs	73
\src\System\Drawing\Design\FontNameEditor.cs	74
\src\System\Windows\Forms\Design\SelectionUIService.ContainerSelectionUIItem.cs	74
\src\System\Windows\Forms\Design\GroupedContextMenuStrip.cs	75
\src\System\Windows\Forms\Design\ImageCollectionCodeDomSerializer.cs	75
\src\System\Windows\Forms\Design\MaskDescriptorComparer.cs	75
\src\System\Windows\Forms\Design\MaskPropertyEditor.cs	75
\src\System\ComponentModel\Design\Serialization\ContainerCodeDomSerializer.cs	77
\src\System\Windows\Forms\Design\FormatStringEditor.cs	77
\src\System\ComponentModel\Design\Serialization\EventMemberCodeDomSerializer.cs	80
\src\System\ComponentModel\Design\TypeDescriptorFilterService.cs	80
\src\System\Windows\Forms\Design\ControlDesigner.TransparentBehavior.cs	80
\src\System\Windows\Forms\Design\MaskedTextBoxTextEditorDropDown.cs	80
\src\System\Windows\Forms\Design\Behavior\Adorner.cs	81
\src\System\ComponentModel\Design\DesignSurfaceCollection.cs	83
\src\System\ComponentModel\Design\DateTimeEditor.DateTimeUI.cs	85
\src\System\Windows\Forms\Design\DocumentDesigner.DocumentInheritanceService.cs	87
\src\System\Windows\Forms\Design\TableLayoutControlCollectionCodeDomSerializer.cs	88
\src\System\Windows\Forms\Design\TextBoxDesigner.cs	88
\src\System\Windows\Forms\Design\ControlDesigner.ControlDesignerAccessibleObject.cs	90
\src\System\Windows\Forms\Design\ListViewActionList.cs	91
\src\System\Windows\Forms\Design\EventHandlerService.cs	92
\src\System\Windows\Forms\Design\ListViewSubItemCollectionEditor.cs	92
\src\System\ComponentModel\Design\DesignerActionList.cs	94
\src\System\Windows\Forms\Design\DesignerExtenders.NameExtenderProvider.cs	95
\src\System\ComponentModel\Design\Serialization\EnumCodeDomSerializer.cs	96
\src\System\Drawing\Design\CursorEditor.CursorUI.cs	96
\src\System\ComponentModel\Design\CollectionEditor.FilterListBox.cs	97
\src\System\Windows\Forms\Design\AxImporter.cs	97
\src\System\ComponentModel\Design\DesignerActionUIService.cs	98
\src\System\Windows\Forms\Design\FolderNameEditor.FolderBrowser.cs	98
\src\System\Windows\Forms\Design\RichTextBoxDesigner.cs	99
\src\System\Windows\Forms\Design\ContextMenuStripActionList.cs	100
\src\System\Windows\Forms\Design\PictureBoxDesigner.cs	101
\src\System\Windows\Forms\Design\InheritanceUI.cs	103
\src\System\Windows\Forms\Design\ImageListImageEditor.cs	107
\src\System\Windows\Forms\Design\StandardCommandToolStripMenuItem.cs	107
\src\System\ComponentModel\Design\DesignerActionPanel.MethodLine.cs	109
\src\System\Windows\Forms\Design\Behavior\GlyphCollection.cs	109
\src\System\Windows\Forms\Design\MenuCommands.cs	110
\src\System\Drawing\Design\IconEditor.cs	111
\src\System\Windows\Forms\Design\StatusCommandUI.cs	112
\src\System\Windows\Forms\Design\ImageCollectionEditor.cs	113
\src\System\ComponentModel\Design\BinaryEditor.cs	117
\src\System\ComponentModel\Design\DesignerActionPanel.PanelHeaderLine.cs	121
\src\System\ComponentModel\Design\Serialization\ResourcePropertyMemberCodeDomSerializer.cs	123
\src\System\ComponentModel\Design\MultilineStringEditor.OleCallback.cs	124
\src\System\Windows\Forms\Design\GroupBoxDesigner.cs	124
\src\System\ComponentModel\Design\DesignerActionPanel.PropertyLine.cs	125
\src\System\Drawing\Design\SelectionPanelBase.cs	125
\src\System\Windows\Forms\Design\CompositionDesigner.cs	125
\src\System\Windows\Forms\Design\ToolStripEditorManager.cs	127
\src\System\ComponentModel\Design\Serialization\CodeDomSerializationProvider.cs	128
\src\System\Windows\Forms\Design\ComboBoxDesigner.cs	128
\src\System\Windows\Forms\Design\LinkAreaEditor.LinkAreaUI.cs	132
\src\System\ComponentModel\Design\Serialization\CodeDomDesignerLoader.ModifiersInheritedExtenderProvider.cs	134
\src\System\Drawing\Design\ColorEditor.CustomColorDialog.cs	134
\src\System\Windows\Forms\Design\ChangeToolStripParentVerb.cs	138
\src\System\Windows\Forms\Design\Behavior\DesignerActionBehavior.cs	139
\src\System\Windows\Forms\Design\TemplateNodeCustomMenuItemCollection.cs	139
\src\System\ComponentModel\Design\SiteNestedContainer.cs	140
\src\System\ComponentModel\Design\Serialization\CodeDomDesignerLoader.ModifierConverter.cs	141
\src\System\Drawing\Design\IToolboxService.cs	142
\src\System\Windows\Forms\Design\MaskDescriptor.cs	142
\src\System\Windows\Forms\Design\LabelDesigner.cs	146
\src\System\Windows\Forms\Design\TextBoxBaseDesigner.cs	148
\src\System\ComponentModel\Design\Serialization\LocalizationCodeDomSerializer.cs	149
\src\System\Windows\Forms\Design\EditorServiceContext.cs	158
\src\System\Drawing\Design\ImageEditor.cs	159
\src\System\Windows\Forms\Design\ToolStripActionList.cs	161
\src\System\Windows\Forms\Design\ImageIndexEditor.cs	162
\src\System\Windows\Forms\Design\OleDragDropHandler.CfCodeToolboxItem.cs	162
\src\System\ComponentModel\Design\CollectionEditor.CollectionForm.cs	163
\src\System\Windows\Forms\Design\PbrsForward.cs	164
\src\System\ComponentModel\Design\Serialization\CodeMethodMap.cs	175
\src\System\Windows\Forms\Design\CollectionEditVerbManager.cs	175
\src\System\Windows\Forms\Design\ListViewDesigner.cs	180
\src\System\ComponentModel\Design\Serialization\CodeDomDesignerLoader.ModifiersExtenderProvider.cs	186
\src\System\Windows\Forms\Design\Behavior\BehaviorService.AdornerWindow.MouseHook.cs	190
\src\System\Windows\Forms\Design\StringCollectionEditor.StringCollectionForm.cs	191
\src\System\ComponentModel\Design\ObjectSelectorEditor.Selector.cs	195
\src\System\ComponentModel\Design\Serialization\CodeDomLocalizationProvider.cs	203
\src\System\Windows\Forms\Design\ListBoxDesigner.cs	211
\src\System\Windows\Forms\Design\ButtonBaseDesigner.cs	218
\src\System\Windows\Forms\Design\Behavior\AdornerCollection.cs	221
\src\System\ComponentModel\Design\Serialization\StatementContext.cs	224
\src\System\ComponentModel\Design\Serialization\CodeDomLocalizationProvider.LanguageExtenders.cs	230
\src\System\Windows\Forms\Design\Behavior\ContainerSelectorBehavior.cs	230
\src\System\Windows\Forms\Design\ToolStripInSituService.cs	234
\src\System\Drawing\BitmapSelector.cs	235
\src\System\ComponentModel\Design\EventBindingService.cs	239
\src\System\Windows\Forms\Design\FormatStringDialog.cs	249
\src\System\Windows\Forms\Design\ToolStripAdornerWindowService.cs	256
\src\System\Windows\Forms\Design\MaskedTextBoxDesigner.cs	268
\src\System\ComponentModel\Design\CollectionEditor.SplitButton.cs	269
\src\System\ComponentModel\Design\BinaryEditor.BinaryUI.cs	271
\src\System\ComponentModel\Design\InheritanceService.cs	274
\src\System\Windows\Forms\Design\BaseContextMenuStrip.cs	290
\src\System\ComponentModel\Design\Serialization\ComponentCache.cs	298
\src\System\Windows\Forms\Design\MaskDescriptorTemplate.cs	299
\src\System\Windows\Forms\Design\OleDragDropHandler.ComponentDataObject.cs	302
\src\System\Windows\Forms\Design\AnchorEditor.AnchorUI.cs	304
\src\System\ComponentModel\Design\InheritedPropertyDescriptor.cs	308
\src\System\Windows\Forms\Design\DataGridViewCellStyleBuilder.cs	326
\src\System\Windows\Forms\Design\ShortcutKeysEditor.ShortcutKeysUI.cs	326
\src\System\ComponentModel\Design\DesignerActionPanel.TextBoxPropertyLine.cs	327
\src\System\ComponentModel\Design\CodeMarkers.cs	329
\src\System\Windows\Forms\Design\Behavior\ToolboxItemSnapLineBehavior.cs	338
\src\System\Windows\Forms\Design\DocumentDesigner.AxToolboxItem.cs	338
\src\System\ComponentModel\Design\DesignerActionService.cs	341
\src\System\ComponentModel\Design\DesignerActionUI.DesignerActionToolStripDropDown.cs	342
\src\System\ComponentModel\Design\ReferenceService.cs	343
\src\System\ComponentModel\Design\CollectionEditor.cs	347
\src\System\ComponentModel\Design\MultilineStringEditor.MultilineStringEditorUI.cs	362
\src\System\Drawing\Design\ColorEditor.ColorUI.cs	365
\src\System\Windows\Forms\Design\Behavior\BehaviorService.AdornerWindow.cs	374
\src\System\ComponentModel\Design\DesignerEventService.cs	379
\src\System\ComponentModel\Design\Serialization\CodeDomSerializer.cs	381
\src\System\Windows\Forms\Design\ControlCodeDomSerializer.cs	385
\src\System\ComponentModel\Design\EventBindingService.EventPropertyDescriptor.cs	395
\src\System\Drawing\Design\ColorEditor.ColorPalette.cs	398
\src\System\Windows\Forms\Design\BorderSidesEditor.BorderSidesEditorUI.cs	403
\src\System\ComponentModel\Design\DesignSurfaceManager.cs	410
\src\System\ComponentModel\Design\Serialization\PropertyMemberCodeDomSerializer.cs	411
\src\System\ComponentModel\Design\Serialization\ResourceCodeDomSerializer.cs	421
\src\System\Windows\Forms\Design\FormDocumentDesigner.cs	432
\src\System\ComponentModel\Design\SelectionService.cs	446
\src\System\Windows\Forms\Design\Behavior\SelectionManager.cs	458
\src\System\Windows\Forms\Design\StandardMenuStripVerb.cs	470
\src\System\Windows\Forms\Design\SelectionUIService.SelectionUIItem.cs	488
\src\System\ComponentModel\Design\DesignSurface.cs	491
\src\System\ComponentModel\Design\Serialization\ComponentCodeDomSerializer.cs	513
\src\System\ComponentModel\Design\MenuCommandService.cs	517
\src\System\ComponentModel\Design\Serialization\TypeCodeDomSerializer.cs	541
\src\System\Windows\Forms\Design\DesignerFrame.cs	576
\src\System\Windows\Forms\Design\ToolStripDesignerUtils.cs	584
\src\System\Windows\Forms\Design\SelectionUIHandler.cs	585
\src\System\Windows\Forms\Design\ToolStripItemCustomMenuItemCollection.cs	607
\src\System\ComponentModel\Design\ComponentDesigner.cs	629
\src\System\Windows\Forms\Design\MaskDesignerDialog.cs	632
\src\System\ComponentModel\Design\Serialization\CollectionCodeDomSerializer.cs	648
\src\System\ComponentModel\Design\DesignerActionUI.cs	672
\src\System\Windows\Forms\Design\ToolStripDropDownDesigner.cs	677
\src\System\ComponentModel\Design\ByteViewer.cs	678
\src\System\ComponentModel\Design\DesignerActionPanel.EditorPropertyLine.cs	720
\src\System\ComponentModel\Design\Serialization\ResourceCodeDomSerializer.SerializationResourceManager.cs	733
\src\System\Windows\Forms\Design\Behavior\BehaviorService.cs	765
\src\System\Windows\Forms\Design\DesignerUtils.cs	816
\src\System\Windows\Forms\Design\Behavior\ResizeBehavior.cs	819
\src\System\Resources\Tools\StronglyTypedResourceBuilder.cs	834
\src\System\ComponentModel\Design\Serialization\BasicDesignerLoader.cs	857
\src\System\Drawing\Design\ToolboxItem.cs	894
\src\System\ComponentModel\Design\Serialization\DesignerSerializationManager.cs	896
\src\System\ComponentModel\Design\DesignerActionPanel.cs	899
\src\System\Windows\Forms\Design\ToolStripItemBehavior.cs	905
\src\System\Windows\Forms\Design\Behavior\DropSourceBehavior.cs	1029
\src\System\Windows\Forms\Design\OleDragDropHandler.cs	1045
\src\System\Windows\Forms\Design\Behavior\DragAssistanceManager.cs	1077
\src\System\Windows\Forms\Design\FormatControl.cs	1130
\src\System\ComponentModel\Design\Serialization\CodeDomDesignerLoader.cs	1160
\src\System\Windows\Forms\Design\ToolStripItemDesigner.cs	1177
\src\System\Windows\Forms\Design\SelectionUIService.cs	1197
\src\System\ComponentModel\Design\CollectionEditor.CollectionEditorCollectionForm.cs	1223
\src\System\ComponentModel\Design\UndoEngine.cs	1229
\src\System\Windows\Forms\Design\DocumentDesigner.cs	1346
\src\System\ComponentModel\Design\Serialization\CodeDomComponentSerializationService.cs	1471
\src\System\Windows\Forms\Design\ControlCommandSet.cs	1580
\src\System\ComponentModel\Design\DesignerHost.cs	1615
\src\System\Windows\Forms\Design\ToolStripTemplateNode.cs	1794
\src\System\Windows\Forms\Design\ToolStripKeyboardHandlingService.cs	1891
\src\System\Windows\Forms\Design\ControlDesigner.cs	2205
\src\System\Windows\Forms\Design\ToolStripDesigner.cs	2260
\src\System\Windows\Forms\Design\ParentControlDesigner.cs	2378
\src\System\Windows\Forms\Design\ToolStripMenuItemDesigner.cs	2527
\src\System\Windows\Forms\Design\ComponentTray.cs	2611
\src\System\ComponentModel\Design\Serialization\CodeDomSerializerBase.cs	3020
\src\System\Windows\Forms\Design\CommandSet.cs	3625

Describe the solution you'd like and alternatives you've considered

N/A

Will this feature affect UI controls?

N/A

[ghost]

This issue is now marked as "help wanted", and we’re looking for a community volunteer to work on this issue. If we receive no interest in 180 days, we will close the issue. To learn more about how we handle feature requests, please see our documentation.

Happy Coding!

[elachlan]

I have started work on this. I immediately ran into interfaces in runtime which aren't annotated. Should interfaces be annotated with NRTs?

[halgab]

I think we're going to have issues with all CodeDom related code. Apparently the upstream System.CodeDom dll is not annotated: dotnet/runtime#41720, dotnet/runtime#78036.

[lonitra]

The team has decided to prioritize nullability changes to files in System.Windows.Forms as there are a greater number of users and we have much fuller test coverage here. Current PRs that are open that change nullability in System.Windows.Forms.Design space will be taken to completion, however we will not be prioritizing any new nullability changes in the System.Windows.Forms.Design area. Thank you so much for the amazing work community has done in this space! The team will revisit enabling nullability for files in System.Windows.Forms.Design once enabling nullability is complete in System.Windows.Forms.

FYI @halgab , @gpetrou

[halgab]

That's very understandable. We're not far off for System.Windows.Forms anyway. I see only 17 files that are not fully annotated in this project, without taking into account currently opened PRs

[lonitra]

Thank you for your patience on this! We've revisited this and decided we will start taking a look at new nullability changes in System.Windows.Forms.Design area again. However, when enabling nullability for classes that reside in System.Windows.Forms.Design, test coverage for public methods on the class should be added if it is lacking coverage. These tests should pass before and after nullability changes here to ensure that unintentional behavior changes are not made.

FYI @halgab , @gpetrou