McBasic™ 0.7.881 · Build 881 · 10 min read

Containers · Container

TabControl

Place controls inside TabPage containers and navigate between pages.

35 properties17 events1 methodsDefault: SelectionChanged

Build the TabControl lesson Properties Events Methods

Use it in a Form#

A TabPage is a child of TabControl, and the controls on a page belong to that page. Overlapping controls on the Form itself do not become tab content. Keep the selected page and any Next/Back commands synchronized.

Add TabControl to its intended parent and name it tabHost for this example:

Property	Example value
`Visible`	`True`
`Enabled`	`True`
`SelectedIndex`	`0`

A complete handler from Forms/frmMain.bas. The linked lesson includes its surrounding controls, declarations and helpers.

Forms/frmMain.bas

Private Sub tabHost_Change()
    If tabHost.SelectedTab Is tabPageGeneral Then
        lblStatus.Caption = "General page selected."
    Else
        lblStatus.Caption = "Details page selected."
    End If
End Sub

Properties#

Contract defaults are shown below. Where a new control has a different Designer starting value, that value is listed separately.

`Left`

DoubleDefault: 0

Horizontal position in device-independent points, relative to the parent container.

Range: -100000 to 100000.

`Top`

DoubleDefault: 0

Vertical position in device-independent points, relative to the parent container.

Range: -100000 to 100000.

`Width`

DoubleDefault: 320

Control width in device-independent points.

Range: 0 to 100000.

Designer starting value: 360.

`Height`

DoubleDefault: 220

Control height in device-independent points.

Range: 0 to 100000.

`MinWidth`

DoubleDefault: 0

Minimum control width in device-independent points; 0 lets the parent layout choose.

Range: 0 to 100000.

`MinHeight`

DoubleDefault: 0

Minimum control height in device-independent points; 0 lets the parent layout choose.

Range: 0 to 100000.

`MaxWidth`

DoubleDefault: 100000

Maximum control width in device-independent points.

Range: 0 to 100000.

`MaxHeight`

DoubleDefault: 100000

Maximum control height in device-independent points.

Range: 0 to 100000.

`TabIndex`

LongDefault: 0

Keyboard navigation order within the parent container; lower values come first.

Range: 0 to 100000.

`ZIndex`

LongDefault: 0

Stacking order among sibling controls; larger values appear in front. Equal values preserve document order.

Range: -100000 to 100000.

`Anchor`

StringDefault: "Left,Top"Not in InspectorNot serialized

Edges kept at their authored distance when the parent resizes. Use a comma-separated combination of Left, Top, Right and Bottom; Dock overrides the effective anchor without deleting it.

`Dock`

StringDefault: "None"

Automatic placement within the parent: None, Left, Top, Right, Bottom or Fill. Dock overrides effective Anchor layout without deleting the stored anchors.

`Margin`

StringDefault: "0"

External spacing as one non-negative DIP value or Left,Top,Right,Bottom.

`Visible`

BooleanDefault: True

Whether the control is shown in the running application.

`BackColor`

StringDefault: ""

Container background color as #RRGGBB. Empty uses the current theme background.

`Padding`

StringDefault: "0"

Inner spacing as one non-negative DIP value or Left,Top,Right,Bottom; child coordinates remain relative to the padded content area.

`AccessibleName`

StringDefault: ""

Name announced by assistive technology. Empty uses the stable control Name.

`Cursor`

StringDefault: "Default"

Pointer shown over the control: Default, Arrow, Hand, IBeam, Cross, Wait, Help, SizeAll, SizeNS, SizeWE, SizeNWSE, SizeNESW or NotAllowed.

`Opacity`

DoubleDefault: 1

Visual opacity from 0 (transparent) to 1 (opaque).

Range: 0 to 1.

`DesignLocked`

BooleanDefault: FalseDesigner only

Prevents movement and resizing in the Designer without changing runtime interaction.

`AccessibleDescription`

StringDefault: ""

Additional help text announced by assistive technology.

`AccessibleRole`

StringDefault: "Auto"

Accessibility role override. Auto preserves the native semantic role; explicit values use the corresponding platform automation role.

`AutomationId`

StringDefault: ""

Stable automation identifier; empty uses the component Name.

`TabStop`

BooleanDefault: True

Whether Tab navigation can move focus to this TabControl.

`ToolTipText`

StringDefault: ""

Help text shown when the pointer rests over the running control; empty disables the tooltip.

`Tag`

StringDefault: ""

Application-defined text associated with this control; McBasic™ does not interpret it.

`Enabled`

BooleanDefault: True

Whether the control accepts user interaction in the running application.

`HitTestVisible`

BooleanDefault: True

Whether the running control participates in pointer hit testing. The control remains selectable in the Designer.

`AllowDrop`

BooleanDefault: False

Whether this running control accepts application drag-and-drop operations; Designer movement is separate.

`DragMode`

LongDefault: 0

VB control drag: 0 Manual (code starts a drag with the Drag method) or 1 Automatic (a left-button press starts a drag, and the control raises no Click, MouseDown or MouseUp for that press).

Range: 0 to 1.

`DragIcon`

StringDefault: ""

Case-insensitive name of a declared project image resource shown under the pointer while this control is dragged; empty shows a grey outline of the control.

`SelectedIndex`

LongDefault: 0

Zero-based selected page index; -1 means no page is selected.

Range: -1 to 100000.

`SelectedTab`

ControlDefault: ""Read only in BASICNot in InspectorNot serialized

Reference to the currently selected TabPage, or Nothing when SelectedIndex is -1. This runtime value is read-only and is not stored in the Form layout.

`TabsPerRow`

LongDefault: 0

Classic appearance only: 0 shows the tabs at their caption widths on one row; a positive number lays them out like a VB6 SSTab, that many tabs per row, each an equal share of the width, in as many fixed rows as needed. The VB6 importer sets it from the SSTab's TabsPerRow. Ignored in the macOS appearance.

Range: 0 to 64.

`Index`

LongDefault: -1Read only in BASICDesigner Index row

Position of this control in its control array, 0 to 32767. Several controls share one name only when every one of them has an Index. Absent from the layout, and -1 in code, when the control is not in an array.

Designer values: 0 to 32767. Clear the dedicated Index row for a non-array control; BASIC then reads -1.

Events and parameters#

Replace control with the object’s Name when creating a handler. ByRef arguments may be changed by your handler; ByVal arguments report an input value.

SelectionChanged

Occurs once after the effective selection changes; assigning the same effective selection does not raise it.

Supported aliases: Change. Canonical name: SelectionChanged.