---
title: "Substituted controls and testers"
description: "Every substituted Windows Forms and Avalonia type, its tester, the events it reports and the members its tester adds."
audience: "Users"
kind: "Reference"
status: "Current"
version: "main · v2.1 (preview)"
slug: "controls"
url: "https://docs.allors.com/immersive/controls/"
---

# Substituted controls and testers

> **Status: Current.** Reference for users. The rows of the tables are generated by `docs/scripts/controls-table.mjs` from the library sources and from the list of tester members in that script; `npm test` fails when the rows differ from its output or a tester is missing.

Each row names a type of the UI framework, the substitute class that replaces it, the kind of substitution, the tester that finds it by name, the testing events the substitute raises, including those it inherits from another substitute class, and the members the tester adds beyond `Target` and `Handle`. [Test a Windows Forms application](https://docs.allors.com/immersive/winforms.md) and [Test an Avalonia application](https://docs.allors.com/immersive/avalonia.md) explain how to use them.

<a id="windows-forms"></a>

## Windows Forms

`Allors.Immersive.Winforms` substitutes 82 types of `System.Windows.Forms`, in the namespace `Allors.Immersive.Winforms.Substitutes`, with testers in `Allors.Immersive.Winforms.Testers`. The common dialogs, five of which are sealed, are substituted explicitly by classes that derive from `CommonDialog`; `MessageBox` is substituted through its static `Show` overloads. Every other substitute derives from the type it replaces.

| Substituted type | Substitute | Substitution | Tester | Events reported | Tester members |
| --- | --- | --- | --- | --- | --- |
| `System.Windows.Forms.BindingNavigator` | `BindingNavigator` | Base | `BindingNavigatorTester` |  | `AddNewItem()` |
| `System.Windows.Forms.Button` | `Button` | Base | `ButtonTester` | Click, DoubleClick | `Click()` |
| `System.Windows.Forms.CheckBox` | `CheckBox` | Base | `CheckBoxTester` | CheckedChanged |  |
| `System.Windows.Forms.CheckedListBox` | `CheckedListBox` | Base | `CheckedListBoxTester` | ItemCheck |  |
| `System.Windows.Forms.ColorDialog` | `ColorDialog` | Explicit | `ColorDialogTester` | Shown |  |
| `System.Windows.Forms.ComboBox` | `ComboBox` | Base | `ComboBoxTester` | SelectedItemChanged | `Select<T>(Predicate<T>)` |
| `System.Windows.Forms.ContextMenu` | `ContextMenu` | Base | `ContextMenuTester` |  |  |
| `System.Windows.Forms.ContextMenuStrip` | `ContextMenuStrip` | Base | `ContextMenuStripTester` |  |  |
| `System.Windows.Forms.DataGrid` | `DataGrid` | Base | `DataGridTester` |  |  |
| `System.Windows.Forms.DataGridTextBox` | `DataGridTextBox` | Base | `DataGridTextBoxTester` |  |  |
| `System.Windows.Forms.DataGridView` | `DataGridView` | Base | `DataGridViewTester` |  | `FindRow(predicate)`, `FindRows(predicate)` |
| `System.Windows.Forms.DataGridViewComboBoxEditingControl` | `DataGridViewComboBoxEditingControl` | Base | `DataGridViewComboBoxEditingControlTester` |  |  |
| `System.Windows.Forms.DataGridViewRow` | `DataGridViewRow` | Base | `DataGridViewRowTester` |  |  |
| `System.Windows.Forms.DataGridViewTextBoxEditingControl` | `DataGridViewTextBoxEditingControl` | Base | `DataGridViewTextBoxEditingControlTester` |  |  |
| `System.Windows.Forms.DateTimePicker` | `DateTimePicker` | Base | `DateTimePickerTester` |  |  |
| `System.Windows.Forms.DomainUpDown` | `DomainUpDown` | Base | `DomainUpDownTester` |  |  |
| `System.Windows.Forms.ErrorProvider` | `ErrorProvider` | Base | `ErrorProviderTester` |  |  |
| `System.Windows.Forms.FileDialog` | `FileDialog` | Explicit | — | Shown |  |
| `System.Windows.Forms.FlowLayoutPanel` | `FlowLayoutPanel` | Base | `FlowLayoutPanelTester` |  |  |
| `System.Windows.Forms.FolderBrowserDialog` | `FolderBrowserDialog` | Explicit | `FolderBrowserDialogTester` | Shown |  |
| `System.Windows.Forms.FontDialog` | `FontDialog` | Explicit | `FontDialogTester` | Shown |  |
| `System.Windows.Forms.Form` | `Form` | Base | `FormTester` | Activated, Shown |  |
| `System.Windows.Forms.GroupBox` | `GroupBox` | Base | `GroupBoxTester` |  |  |
| `System.Windows.Forms.HScrollBar` | `HScrollBar` | Base | `HScrollBarTester` |  |  |
| `System.Windows.Forms.HelpProvider` | `HelpProvider` | Base | `HelpProviderTester` |  |  |
| `System.Windows.Forms.Label` | `Label` | Base | `LabelTester` |  |  |
| `System.Windows.Forms.LinkLabel` | `LinkLabel` | Base | `LinkLabelTester` |  |  |
| `System.Windows.Forms.ListBox` | `ListBox` | Base | `ListBoxTester` |  |  |
| `System.Windows.Forms.ListView` | `ListView` | Base | `ListViewTester` |  |  |
| `System.Windows.Forms.MainMenu` | `MainMenu` | Base | `MainMenuTester` |  |  |
| `System.Windows.Forms.MaskedTextBox` | `MaskedTextBox` | Base | `MaskedTextBoxTester` |  |  |
| `System.Windows.Forms.MenuItem` | `MenuItem` | Base | `MenuItemTester` |  | `Click()` |
| `System.Windows.Forms.MenuStrip` | `MenuStrip` | Base | `MenuStripTester` |  |  |
| `System.Windows.Forms.MessageBox` | `MessageBox` | Static `Show` overloads | `MessageBoxTester` | Shown |  |
| `System.Windows.Forms.MonthCalendar` | `MonthCalendar` | Base | `MonthCalendarTester` |  |  |
| `System.Windows.Forms.NumericUpDown` | `NumericUpDown` | Base | `NumericUpDownTester` |  |  |
| `System.Windows.Forms.OpenFileDialog` | `OpenFileDialog` | Explicit | `OpenFileDialogTester` | Shown |  |
| `System.Windows.Forms.PageSetupDialog` | `PageSetupDialog` | Explicit | `PageSetupDialogTester` | Shown |  |
| `System.Windows.Forms.Panel` | `Panel` | Base | `PanelTester` |  |  |
| `System.Windows.Forms.PictureBox` | `PictureBox` | Base | `PictureBoxTester` |  |  |
| `System.Windows.Forms.PrintDialog` | `PrintDialog` | Explicit | `PrintDialogTester` | Shown |  |
| `System.Windows.Forms.PrintPreviewControl` | `PrintPreviewControl` | Base | `PrintPreviewControlTester` |  |  |
| `System.Windows.Forms.PrintPreviewDialog` | `PrintPreviewDialog` | Base | `PrintPreviewDialogTester` |  |  |
| `System.Windows.Forms.ProgressBar` | `ProgressBar` | Base | `ProgressBarTester` |  |  |
| `System.Windows.Forms.PropertyGrid` | `PropertyGrid` | Base | `PropertyGridTester` |  | `FindGridItem(params string[] names)` |
| `System.Windows.Forms.RadioButton` | `RadioButton` | Base | `RadioButtonTester` |  |  |
| `System.Windows.Forms.RichTextBox` | `RichTextBox` | Base | `RichTextBoxTester` |  |  |
| `System.Windows.Forms.SaveFileDialog` | `SaveFileDialog` | Explicit | `SaveFileDialogTester` | Shown |  |
| `System.Windows.Forms.SplitContainer` | `SplitContainer` | Base | `SplitContainerTester` |  |  |
| `System.Windows.Forms.Splitter` | `Splitter` | Base | `SplitterTester` |  |  |
| `System.Windows.Forms.StatusBar` | `StatusBar` | Base | `StatusBarTester` |  |  |
| `System.Windows.Forms.StatusBarPanel` | `StatusBarPanel` | Base | `StatusBarPanelTester` |  |  |
| `System.Windows.Forms.StatusStrip` | `StatusStrip` | Base | `StatusStripTester` |  |  |
| `System.Windows.Forms.TabControl` | `TabControl` | Base | `TabControlTester` |  |  |
| `System.Windows.Forms.TabPage` | `TabPage` | Base | `TabPageTester` |  |  |
| `System.Windows.Forms.TableLayoutPanel` | `TableLayoutPanel` | Base | `TableLayoutPanelTester` |  |  |
| `System.Windows.Forms.TextBox` | `TextBox` | Base | `TextBoxTester` |  |  |
| `System.Windows.Forms.Timer` | `Timer` | Base | `TimerTester` |  |  |
| `System.Windows.Forms.ToolBar` | `ToolBar` | Base | `ToolBarTester` |  | `Click(ToolBarButtonTester)` |
| `System.Windows.Forms.ToolBarButton` | `ToolBarButton` | Base | `ToolBarButtonTester` |  | `Click()` |
| `System.Windows.Forms.ToolStrip` | `ToolStrip` | Base | `ToolStripTester` |  |  |
| `System.Windows.Forms.ToolStripButton` | `ToolStripButton` | Base | `ToolStripButtonTester` |  | `Click()` |
| `System.Windows.Forms.ToolStripComboBox` | `ToolStripComboBox` | Base | `ToolStripComboBoxTester` |  |  |
| `System.Windows.Forms.ToolStripContainer` | `ToolStripContainer` | Base | `ToolStripContainerTester` |  |  |
| `System.Windows.Forms.ToolStripContentPanel` | `ToolStripContentPanel` | Base | `ToolStripContentPanelTester` |  |  |
| `System.Windows.Forms.ToolStripDropDown` | `ToolStripDropDown` | Base | `ToolStripDropDownTester` |  |  |
| `System.Windows.Forms.ToolStripDropDownButton` | `ToolStripDropDownButton` | Base | `ToolStripDropDownButtonTester` |  |  |
| `System.Windows.Forms.ToolStripDropDownMenu` | `ToolStripDropDownMenu` | Base | `ToolStripDropDownMenuTester` |  |  |
| `System.Windows.Forms.ToolStripLabel` | `ToolStripLabel` | Base | `ToolStripLabelTester` |  |  |
| `System.Windows.Forms.ToolStripMenuItem` | `ToolStripMenuItem` | Base | `ToolStripMenuItemTester` |  |  |
| `System.Windows.Forms.ToolStripPanel` | `ToolStripPanel` | Base | `ToolStripPanelTester` |  |  |
| `System.Windows.Forms.ToolStripProgressBar` | `ToolStripProgressBar` | Base | `ToolStripProgressBarTester` |  |  |
| `System.Windows.Forms.ToolStripSeparator` | `ToolStripSeparator` | Base | `ToolStripSeparatorTester` |  |  |
| `System.Windows.Forms.ToolStripSplitButton` | `ToolStripSplitButton` | Base | `ToolStripSplitButtonTester` |  |  |
| `System.Windows.Forms.ToolStripStatusLabel` | `ToolStripStatusLabel` | Base | `ToolStripStatusLabelTester` |  |  |
| `System.Windows.Forms.ToolStripTextBox` | `ToolStripTextBox` | Base | `ToolStripTextBoxTester` |  |  |
| `System.Windows.Forms.ToolTip` | `ToolTip` | Base | `ToolTipTester` |  |  |
| `System.Windows.Forms.TrackBar` | `TrackBar` | Base | `TrackBarTester` |  |  |
| `System.Windows.Forms.TreeView` | `TreeView` | Base | `TreeViewTester` | NodeMouseClick, NodeMouseHover | `SelectNode(params int[])`, `SelectNode(TreeNodeTester)`, `FindNode(params int[])`, `SelectedNode`, `this[string[] ancestors]` |
| `System.Windows.Forms.UserControl` | `UserControl` | Base | `UserControlTester` |  |  |
| `System.Windows.Forms.VScrollBar` | `VScrollBar` | Base | `VScrollBarTester` |  |  |
| `System.Windows.Forms.WebBrowser` | `WebBrowser` | Base | `WebBrowserTester` |  |  |

Two testers address parts of a control rather than a control: `GridItemTester`, returned by `PropertyGridTester.FindGridItem`, with `Value`, `Children` and `Edit()`; and `TreeNodeTester`, returned by `TreeViewTester.FindNode` and its indexer, with `Target`, `TreeViewTester`, `Select()`, `Click()`, `FindByTagType(Type)` and an indexer for child nodes.

<a id="testing-events"></a>

### Testing events

`TestingWinformsEventKind` lists many kinds of event, but the substitutes raise these nine: `Activated`, `CheckedChanged`, `Click`, `DoubleClick`, `ItemCheck`, `NodeMouseClick`, `NodeMouseHover`, `SelectedItemChanged` and `Shown`. `Shown` is raised by `Form`, by every common dialog from `RunDialog`, and by `MessageBox.Show`.

<a id="avalonia"></a>

## Avalonia

`Allors.Immersive.Avalonia` substitutes 49 controls of `Avalonia.Controls`, in the namespace `Allors.Immersive.Avalonia.Substitutes`, with testers in `Allors.Immersive.Avalonia.Testers`. Every substitute derives from the control it replaces and overrides `StyleKeyOverride` so that the theme still applies.

| Substituted type | Substitute | Substitution | Tester | Events reported | Tester members |
| --- | --- | --- | --- | --- | --- |
| `Avalonia.Controls.AutoCompleteBox` | `AutoCompleteBox` | Base | `AutoCompleteBoxTester` | TextChanged |  |
| `Avalonia.Controls.Border` | `Border` | Base | `BorderTester` |  |  |
| `Avalonia.Controls.Button` | `Button` | Base | `ButtonTester` | Click | `Click()` |
| `Avalonia.Controls.Calendar` | `Calendar` | Base | `CalendarTester` | SelectionChanged |  |
| `Avalonia.Controls.CalendarDatePicker` | `CalendarDatePicker` | Base | `CalendarDatePickerTester` | ValueChanged |  |
| `Avalonia.Controls.Canvas` | `Canvas` | Base | `CanvasTester` |  |  |
| `Avalonia.Controls.Carousel` | `Carousel` | Base | `CarouselTester` |  |  |
| `Avalonia.Controls.CheckBox` | `CheckBox` | Base | `CheckBoxTester` | IsCheckedChanged |  |
| `Avalonia.Controls.ComboBox` | `ComboBox` | Base | `ComboBoxTester` | SelectionChanged |  |
| `Avalonia.Controls.ContentControl` | `ContentControl` | Base | `ContentControlTester` |  |  |
| `Avalonia.Controls.ContextMenu` | `ContextMenu` | Base | `ContextMenuTester` |  |  |
| `Avalonia.Controls.DatePicker` | `DatePicker` | Base | `DatePickerTester` | ValueChanged |  |
| `Avalonia.Controls.DockPanel` | `DockPanel` | Base | `DockPanelTester` |  |  |
| `Avalonia.Controls.Expander` | `Expander` | Base | `ExpanderTester` | IsExpandedChanged |  |
| `Avalonia.Controls.Grid` | `Grid` | Base | `GridTester` |  |  |
| `Avalonia.Controls.GridSplitter` | `GridSplitter` | Base | `GridSplitterTester` |  |  |
| `Avalonia.Controls.Image` | `Image` | Base | `ImageTester` |  |  |
| `Avalonia.Controls.ItemsControl` | `ItemsControl` | Base | `ItemsControlTester` |  |  |
| `Avalonia.Controls.Label` | `Label` | Base | `LabelTester` |  |  |
| `Avalonia.Controls.ListBox` | `ListBox` | Base | `ListBoxTester` | SelectionChanged |  |
| `Avalonia.Controls.ListBoxItem` | `ListBoxItem` | Base | `ListBoxItemTester` |  |  |
| `Avalonia.Controls.Menu` | `Menu` | Base | `MenuTester` |  |  |
| `Avalonia.Controls.MenuItem` | `MenuItem` | Base | `MenuItemTester` | Click | `Click()` |
| `Avalonia.Controls.NumericUpDown` | `NumericUpDown` | Base | `NumericUpDownTester` | ValueChanged |  |
| `Avalonia.Controls.Panel` | `Panel` | Base | `PanelTester` |  |  |
| `Avalonia.Controls.ProgressBar` | `ProgressBar` | Base | `ProgressBarTester` | ValueChanged |  |
| `Avalonia.Controls.RadioButton` | `RadioButton` | Base | `RadioButtonTester` | IsCheckedChanged |  |
| `Avalonia.Controls.RepeatButton` | `RepeatButton` | Base | `RepeatButtonTester` | Click | `Click()` |
| `Avalonia.Controls.ScrollViewer` | `ScrollViewer` | Base | `ScrollViewerTester` |  |  |
| `Avalonia.Controls.SelectableTextBlock` | `SelectableTextBlock` | Base | `SelectableTextBlockTester` |  |  |
| `Avalonia.Controls.Separator` | `Separator` | Base | `SeparatorTester` |  |  |
| `Avalonia.Controls.Slider` | `Slider` | Base | `SliderTester` | ValueChanged |  |
| `Avalonia.Controls.SplitButton` | `SplitButton` | Base | `SplitButtonTester` | Click | `Click()` |
| `Avalonia.Controls.SplitView` | `SplitView` | Base | `SplitViewTester` |  |  |
| `Avalonia.Controls.StackPanel` | `StackPanel` | Base | `StackPanelTester` |  |  |
| `Avalonia.Controls.TabControl` | `TabControl` | Base | `TabControlTester` | SelectionChanged |  |
| `Avalonia.Controls.TabItem` | `TabItem` | Base | `TabItemTester` |  |  |
| `Avalonia.Controls.TextBlock` | `TextBlock` | Base | `TextBlockTester` |  |  |
| `Avalonia.Controls.TextBox` | `TextBox` | Base | `TextBoxTester` | TextChanged |  |
| `Avalonia.Controls.TimePicker` | `TimePicker` | Base | `TimePickerTester` | ValueChanged |  |
| `Avalonia.Controls.Primitives.ToggleButton` | `ToggleButton` | Base | `ToggleButtonTester` | Click, IsCheckedChanged | `Click()` |
| `Avalonia.Controls.ToggleSplitButton` | `ToggleSplitButton` | Base | `ToggleSplitButtonTester` | Click, IsCheckedChanged | `Click()` |
| `Avalonia.Controls.ToggleSwitch` | `ToggleSwitch` | Base | `ToggleSwitchTester` | IsCheckedChanged |  |
| `Avalonia.Controls.TreeView` | `TreeView` | Base | `TreeViewTester` | SelectionChanged |  |
| `Avalonia.Controls.TreeViewItem` | `TreeViewItem` | Base | `TreeViewItemTester` |  |  |
| `Avalonia.Controls.UserControl` | `UserControl` | Base | `UserControlTester` |  |  |
| `Avalonia.Controls.Viewbox` | `Viewbox` | Base | `ViewboxTester` |  |  |
| `Avalonia.Controls.Window` | `Window` | Base | `WindowTester` | Closed, Opened |  |
| `Avalonia.Controls.WrapPanel` | `WrapPanel` | Base | `WrapPanelTester` |  |  |

<a id="testing-events-1"></a>

### Testing events

`TestingAvaloniaEventKind` has eight kinds, all raised by substitutes: `Click`, `Closed`, `IsCheckedChanged`, `IsExpandedChanged`, `Opened`, `SelectionChanged`, `TextChanged` and `ValueChanged`.