TCustomFloatSpinEdit.Value property
The floating point value for the spin edit control.
Declaration
property Value: Double read GetValue write SetValue;Description
Value is a Double property which contains the floating point value
for the spin edit control. It can be modified using the UI elements for the
control (up and down buttons, up and down cursor keys, or the edit box for
the control). It can also be assigned directly in program code.
Value is a 64-bit real type in the range 5.0E-324 .. 1.7E308 (inclusive), and allows up to 15-16 digits of precision (15 digits for a negative value).
Changing the value for the property causes the Text for the
control to be checked for a valid numeric representation for the property. If
the new property value is the same as the existing value, no actions are
performed.
When the property value has been stored, internal flags are set to ensure
that Modified is updated accordingly and the private
UpdateControl method is called. If the handle for the control has
been allocated, the Change method is called to post a
CM_CHANGED control message and signal OnChange handler(s)
assigned for the control.
When changed, Value is constrained to the range defined in the
MinValue and MaxValue properties (when assigned). The
range limits are not enforced when MinValue and MaxValue have the same value,
or when MaxValue is smaller than MinValue. When neither MinValue nor MaxValue
have been assigned, either -Inf or +Inf is displayed as the value for the
control. If either MinValue or MaxValue has been given an explicit
non-default value, the Value property is updated with corresponding range
limit.
In LCL version 3.0, the floating point property editor will not allow an invalid value to be stored in the Value property at design-time. An error is raised (and handled) with the message 'Property value out of range', and the Value property is not updated.
LCL versions prior to 3.0 allowed the values +Inf, -Inf, and NaN to be assigned as the property value. These values are no longer supported in LCL version 3.0 and later.
Use the MinValue and MaxValue properties to define the lower and upper limits for the Value in the control. Like Value, they are implemented as a Double type with the same range limits. An invalid value causes the property to be set to the corresponding range limit for the real type.
Use the DecimalPlaces property to specify the number of decimal digits displayed for a value not represented using the radix/precision/exponent format for the IEE 754 value.
Use the Increment property to set the value added to or subtracted from the control Value when the up or down buttons are clicked.
See also
An experiment, built from development snapshots. Not the official Free Pascal or Lazarus documentation.