QDoubleSpinBox Class

成员函数

QDoubleSpinBox::QDoubleSpinBox(QWidget *parent = Q_NULLPTR)

Constructs a spin box with 0.0 as minimum value and 99.99 as maximum value, a step value of 1.0 and a precision of 2 decimal places. The value is initially set to 0.00. The spin box has the given parent.

参见 setMinimum(), setMaximum(), and setSingleStep().

QDoubleSpinBox::~QDoubleSpinBox()

Destructor.

[override virtual] void QDoubleSpinBox::fixup(QString &input) const

重新实现 QAbstractSpinBox::fixup().

void QDoubleSpinBox::setRange(double minimum, double maximum)

Convenience function to set the minimum and maximum values with a single function call.

Note: The maximum and minimum values will be rounded to match the decimals property.

  setRange(minimum, maximum);

is equivalent to:

  setMinimum(minimum);
  setMaximum(maximum);

参见 minimum and maximum.

[virtual] QString QDoubleSpinBox::textFromValue(double value) const

This virtual function is used by the spin box whenever it needs to display the given value. The default implementation returns a string containing value printed using QWidget::locale().toString(value, QLatin1Char('f'), decimals()) and will remove the thousand separator unless setGroupSeparatorShown() is set. Reimplementations may return anything.

Note: QDoubleSpinBox does not call this function for specialValueText() and that neither prefix() nor suffix() should be included in the return value.

If you reimplement this, you may also need to reimplement valueFromText().

参见 valueFromText() and QLocale::groupSeparator().

[override virtual] QValidator::State QDoubleSpinBox::validate(QString &text, int &pos) const

重新实现 QAbstractSpinBox::validate().

[signal] void QDoubleSpinBox::valueChanged(double d)

This signal is emitted whenever the spin box's value is changed. The new value is passed in d.

Note: Signal valueChanged is overloaded in this class. To connect to this one using the function pointer syntax, you must specify the signal type in a static cast, as shown in this example:

  connect(doubleSpinBox, static_cast<void(QDoubleSpinBox::*)(double)>(&QDoubleSpinBox::valueChanged),
      [=](double d){ /* ... */ });

Note: Notifier signal for property value.

[signal] void QDoubleSpinBox::valueChanged(const QString &text)

This is an overloaded function.

The new value is passed in text with prefix() and suffix().

Note: Signal valueChanged is overloaded in this class. To connect to this one using the function pointer syntax, you must specify the signal type in a static cast, as shown in this example:

  connect(doubleSpinBox, static_cast<void(QDoubleSpinBox::*)(const QString &)>(&QDoubleSpinBox::valueChanged),
      [=](const QString &text){ /* ... */ });

Note: Notifier signal for property value.

[virtual] double QDoubleSpinBox::valueFromText(const QString &text) const

This virtual function is used by the spin box whenever it needs to interpret text entered by the user as a value.

Subclasses that need to display spin box values in a non-numeric way need to reimplement this function.

Note: QDoubleSpinBox handles specialValueText() separately; this function is only concerned with the other values.

参见 textFromValue() and validate().