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Published 20 hours ago • verified publisher icon dotnet

Control classes leaking memory

Open dkazennov opened this issue 2 years ago • 8 comments

.NET version

.NET 7.0 Preview 4

Did it work in .NET Framework?

No

Did it work in any of the earlier releases of .NET Core or .NET 5+?

No response

Issue description

Investigating possible memory leaks with Windows Forms classes inherited to Control class AND in corresponding Accessible Objects. Some control items and some accessible objects are left in memory after the control instance with its items was inspected with accessibility tool (like Accessibility Insights or Inspect) and the form with the control is closed, garbage is collected, but accessibility tool is still opened.

Abstract, private and internal control classes which can't be placed in a form Controls collection are not applicable. Control classes from the namespace System.Windows.Forms.Design are not not applicable.

Table 1. Control classes tested for memory leaks:

Class name Base class name Memory leaks Issue assigned Status
DataGridView Control Is leaking #7347 Waiting for review
PropertyGrid ContainerControl Is leaking #6943 Work in progress
DomainUpDown UpDownBase Is leaking #7328 Fixed
ToolStrip ScrollableControl Is leaking #7375 Fixed
ListBox ListControl Is leaking #7197 Fixed
ListView Control Is leaking #7385 Fixed
CheckedListBox ListBox Is leaking #7197 Fixed
ComboBox ListControl Is leaking #7318 Fixed
TextBox TextBoxBase Is leaking #7248 Work in progress
TreeView Control Is leaking #7196 Fixed
MonthCalendar Control Is leaking #6852 Fixed
NumericUpDown UpDownBase Is leaking #7328 Fixed
TabPage Panel Is leaking (when tested with Narrator) #7415 Fixed
Button ButtonBase Is not leaking  
CheckBox ButtonBase Is not leaking  
RadioButton ButtonBase Is not leaking  
DateTimePicker Control Is not leaking  
GroupBox Control Is not leaking  
ThreadExceptionDialog Form Is not leaking  
UpDownBase ContainerControl Is not leaking  
SplitterPanel Panel Is not leaking  
BindingNavigator ToolStrip Is not leaking
MenuStrip ToolStrip Is not leaking  
StatusStrip ToolStrip Is not leaking  
ContextMenuStrip ToolStripDropDownMenu Is not leaking  
ToolStripOverflow ToolStripDropDown Is not leaking  
HScrollBar ScrollBar Is not leaking  
VScrollBar ScrollBar Is not leaking  
Label Control Is not leaking  
LinkLabel Label Is not leaking  
ProgressBar Control Is not leaking  
RichTextBox TextBoxBase Is not leaking
MaskedTextBox TextBoxBase Is not leaking  
TabControl Control Is not leaking  
TrackBar Control Is not leaking  
DataGridViewTextBoxEditingControl TextBox Is not leaking  
PrintPreviewControl Control Is not leaking  
ToolStripPanel ContainerControl Is not leaking  
SplitContainer ContainerControl Is not leaking  
ToolStripContainer ContainerControl Is not leaking  
Panel ScrollableControl Is not leaking  
TableLayoutPanel Panel Is not leaking  
ToolStripContentPanel Panel Is not leaking  
DataGridViewComboBoxEditingControl ComboBox Is not leaking  
PictureBox Control Is not leaking  
ColorEditorTabControl TabControl Is not leaking
Splitter Control Is not leaking
WebBrowser WebBrowserBase Is not leaking Deprecated 

Table 2. Control classes that are not applicable on the form:

Class name Base class name
Control  
AdornerWindow Control
AnchorUI Control
AxHost Control
ButtonBase Control
DetailsButton Button
DropDownButton Button
EditorButton Button
SplitButton Button
DockEditorCheckBox CheckBox
ColorPalette Control
ColorUI Control
ContainerPlaceholder Control
ContentUI Control
ControlPlaceholder Control
DateTimeUI Control
DesignerFrame Control
DockUI Control
GridToolTip Control
SelectionUIService Control
ScrollableControl Control
ComponentTray ScrollableControl
ContainerControl ScrollableControl
DesignerActionPanel ContainerControl
BinaryUI Form
CollectionForm Form
CollectionEditorCollectionForm CollectionForm
StringCollectionForm CollectionForm
ComponentEditorForm Form
DataGridViewCellStyleBuilder Form
DropDownHolder Form
FormatStringDialog Form
FlyoutDialog Form
DropDownHolder FlyoutDialog
GridErrorDialog Form
PrintPreviewDialog Form
StatusDialog Form
LinkAreaUI Form
MaskDesignerDialog Form
MdiWindowDialog Form
ParkingWindow ContainerControl
ToolStripNumericUpDownControl NumericUpDown
UserControl ContainerControl
BorderSidesEditorUI UserControl
FormatControl UserControl
ShortcutKeysUI UserControl
MaskedTextBoxTextEditorDropDown UserControl
OverlayControl ScrollableControl
ComponentEditorPage Panel
DataGridViewEditingPanel Panel
FlowLayoutPanel Panel
ByteViewer TableLayoutPanel
ToolStripEditorControl Panel
PropertyGridToolStrip ToolStrip
MdiControlStrip MenuStrip
MdiWindowListStrip MenuStrip
ToolStripDropDown ToolStrip
DesignerActionToolStripDropDown ToolStripDropDown
FeedbackDropDown ToolStripDropDown
ToolStripDropDownMenu ToolStripDropDown
GroupedContextMenuStrip ContextMenuStrip
BaseContextMenuStrip GroupedContextMenuStrip
NewItemsContextMenuStrip GroupedContextMenuStrip
TransparentToolStrip ToolStrip
ScrollBar Control
SKWindow Control
SpringControl Control
EditorLabel Label
MethodItemLinkLabel LinkLabel
StickyLabel Label
ListControl Control
ColorEditorListBox ListBox
CursorUI ListBox
GridViewListBox ListBox
FilterListBox ListBox
ToolStripComboBoxControl ComboBox
MarshalingControl Control
MdiClient Control
DateTimeMonthCalendar MonthCalendar
RightToLeftLayoutGrip Control
ToolStripProgressBarControl ProgressBar
PropertyGridView Control
SnappableControl Control
CommandsPane PropertyGrid.SnappableControl
HelpPane PropertyGrid.SnappableControl
TabOrder Control
TextBoxBase Control
MultilineStringEditorUI RichTextBox
ridViewTextBox TextBox
mplateTextBox TextBox
ToolStripTextBoxControl TextBox
UpDownEdit TextBox
ToolStripAdornerWindow Control
TrayControl Control
PageSelector TreeView
Selector TreeView
UpDownButtons Control
WebBrowserBase Control

Steps to reproduce

  1. Include a MemoryLeaks_Form to WinformsControlsTest (impemented in https://github.com/dkazennov/winforms/tree/MemoryLeaks_Form).
  2. Test each form with WinDbg and Inspect.

The separate application to test memory leaks (it uses checkbox instead of buttons to switch between the forms to isolate the Button tested class memory objects): MemoryLeaksApp.zip

dkazennov avatar Jun 21 '22 14:06 dkazennov

To confirm - are controls leaking memory, or their AO implementations?

RussKie avatar Jun 22 '22 07:06 RussKie

To confirm - are controls leaking memory, or their AO implementations?

There are problems both with Controls and Accessible objects. This issue is to investigate the whole problem and to create subsequent issues.

dkazennov avatar Jun 22 '22 09:06 dkazennov

  • [ ] Button control: image
  • [ ] CheckBox control: image
  • [ ] DataGridView control: image
  • [ ] ListView: image
  • [ ] RichTextBox: image
  • [ ] MaskexTextBox: image
  • [ ] CheckedListBox: image
  • [ ] Panel: image
  • [ ] WebBrowser: image

dkazennov avatar Jun 23 '22 12:06 dkazennov

ToolStrip: image

vladimir-krestov avatar Jun 29 '22 10:06 vladimir-krestov

TabPage leaks when tested with Narrator: image

dkazennov avatar Jun 29 '22 13:06 dkazennov

I tested the Button control class in a standalone application without buttons to switch between forms (checkboxes are being used instead). If there are no buttons in the application (only the Button to test the control class), then there will be no Button class object and Button.AccessibleObject class object in the Heap after the manual garbage collection.

image

dkazennov avatar Jul 04 '22 15:07 dkazennov

Retested controls - found no leaks:

  • ListView
  • RichTextBox
  • MaskedTextBox
  • [ ] ListView: image
  • [ ] RichTextBox: image
  • [ ] MaskedTextBox: image

dkazennov avatar Jul 06 '22 09:07 dkazennov

I found that ListView does have a leak, if testing with Narrator or not refreshing tree in Inspect. Will be tracked in #7385. image

dmitrii-drobotov avatar Jul 07 '22 15:07 dmitrii-drobotov

This issue was addressed in https://github.com/dotnet/winforms/issues/9224

Tanya-Solyanik avatar Jul 13 '23 02:07 Tanya-Solyanik