McBasic™ 0.7.881 · Build 881 · 11 min read

Controls · Visual control

NumericBox

Work with a numeric value and validate its allowed range.

45 properties18 events1 methodsDefault: Change

Build the NumericBox lesson Properties Events Methods

Use it in a Form#

Read Value for calculations rather than parsing a caption. Keep Minimum, Maximum and formatting consistent with the quantity being edited. Test an invalid intermediate edit as well as a final valid number: the user may temporarily leave a field empty while typing.

Add NumericBox to its intended parent and name it numAmount for this example:

Property	Example value
`Minimum`	`-100`
`Maximum`	`100`
`Value`	`12.5`
`Increment`	`0.5`
`DecimalPlaces`	`1`
`ThousandsSeparator`	`True`
`Prefix`	`"$ "`
`Suffix`	`" USD"`
`Alignment`	`"Right"`
`ReadOnly`	`False`
`Culture`	`"Invariant"`

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

Forms/frmMain.bas

Private Sub numAmount_Change()
    If numAmount.IsValid Then
        lblStatus.Caption = "Value: " & numAmount.Value
    Else
        lblStatus.Caption = numAmount.ValidationError
    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: 180

Control width in device-independent points.

Range: 0 to 100000.

`Height`

DoubleDefault: 32

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.

`Visible`

BooleanDefault: True

Whether the control is shown in the running application.

`Font`

StringDefault: ""

NumericBox displayed value font as Family|Size or Family|Size|Regular/Bold|Normal/Italic, size 6–96 DIP. Empty uses the theme font.

`ForeColor`

StringDefault: ""

NumericBox displayed value text color as #RRGGBB. Empty uses the current theme color.

`BackColor`

StringDefault: ""

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

`Margin`

StringDefault: "0"

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

`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.

`AutomationId`

StringDefault: ""

Stable automation identifier; empty uses the component Name.

`AccessibleName`

StringDefault: ""

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

`AccessibleRole`

StringDefault: "Auto"

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

`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.

`ReadOnly`

BooleanDefault: False

Prevents user edits while keeping the numeric value readable and writable from BASIC.

`TabStop`

BooleanDefault: True

Whether Tab navigation can move focus to this NumericBox.

`Minimum`

DoubleDefault: 0

Smallest numeric input value.

Range: -1000000000 to 1000000000.

`Maximum`

DoubleDefault: 100

Largest numeric input value; must be greater than Minimum.

Range: -1000000000 to 1000000000.

`Value`

DoubleDefault: 0

Current numeric input value between Minimum and Maximum.

Range: -1000000000 to 1000000000.

`Step`

DoubleDefault: 1Not in Inspector

Legacy compatibility alias for Increment; new projects edit and serialize Increment.

Range: 1e-10 to 1000000000.

`Increment`

DoubleDefault: 1

Amount added or subtracted by each spin action.

Range: 1e-10 to 1000000000.

`DecimalPlaces`

LongDefault: 0

Number of fractional digits displayed and accepted.

Range: 0 to 15.

`ThousandsSeparator`

BooleanDefault: False

Whether the displayed number uses culture-specific digit grouping.

`Prefix`

StringDefault: ""

Presentation text shown before the numeric value; it is not part of Value.

`Suffix`

StringDefault: ""

Presentation text shown after the numeric value; it is not part of Value.

`Alignment`

StringDefault: "Right"

Numeric text alignment: Left, Center or Right.

`Culture`

StringDefault: "Invariant"

Explicit parsing culture name, or Invariant for dot-decimal parsing.

`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.