QDoubleSpinBox ¶

概要 ¶

详细描述 ¶

QDoubleSpinBox allows the user to choose a value by clicking the up and down buttons or by pressing Up or Down on the keyboard to increase or decrease the value currently displayed. The user can also type the value in manually. The spin box supports double values but can be extended to use different strings with validate() , textFromValue() and valueFromText() .

Every time the value changes QDoubleSpinBox 发射 valueChanged() and textChanged() signals, the former providing a double and the latter a QString 。 textChanged() signal provides the value with both prefix() and suffix() . The current value can be fetched with value() and set with setValue() .

注意： QDoubleSpinBox will round numbers so they can be displayed with the current precision. In a QDoubleSpinBox with decimals set to 2, calling setValue (2.555) will cause value() to return 2.56.

Clicking the up and down buttons or using the keyboard accelerator’s Up and Down arrows will increase or decrease the current value in steps of size singleStep() . If you want to change this behavior you can reimplement the virtual function stepBy() . The minimum and maximum value and the step size can be set using one of the constructors, and can be changed later with setMinimum() , setMaximum() and setSingleStep() . The spinbox has a default precision of 2 decimal places but this can be changed using setDecimals() .

Most spin boxes are directional, but QDoubleSpinBox can also operate as a circular spin box, i.e. if the range is 0.0-99.9 and the current value is 99.9, clicking “up” will give 0 if wrapping() is set to true. Use setWrapping() if you want circular behavior.

The displayed value can be prepended and appended with arbitrary strings indicating, for example, currency or the unit of measurement. See setPrefix() and setSuffix() . The text in the spin box is retrieved with text() (which includes any prefix() and suffix() ), or with cleanText() (which has no prefix() , no suffix() and no leading or trailing whitespace).

It is often desirable to give the user a special (often default) choice in addition to the range of numeric values. See setSpecialValueText() for how to do this with QDoubleSpinBox .

注意

The displayed value of the QDoubleSpinBox is limited to 18 characters in addition to eventual prefix and suffix content. This limitation is used to keep the double spin box usable even with extremely large values.

另请参阅

QSpinBox QDateTimeEdit QSlider 自旋框范例

class QDoubleSpinBox ( [ parent=None ] ) ¶

param parent

QWidget

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 .

另请参阅

setMinimum() setMaximum() setSingleStep()

PySide2.QtWidgets.QDoubleSpinBox. cleanText ( ) ¶

返回类型

unicode

PySide2.QtWidgets.QDoubleSpinBox. decimals ( ) ¶

返回类型

int

另请参阅

setDecimals()

PySide2.QtWidgets.QDoubleSpinBox. maximum ( ) ¶

返回类型

double

另请参阅

setMaximum()

PySide2.QtWidgets.QDoubleSpinBox. minimum ( ) ¶

返回类型

double

另请参阅

setMinimum()

PySide2.QtWidgets.QDoubleSpinBox. prefix ( ) ¶

返回类型

unicode

另请参阅

setPrefix()

PySide2.QtWidgets.QDoubleSpinBox. setDecimals ( prec ) ¶

参数

prec – int

另请参阅

decimals()

PySide2.QtWidgets.QDoubleSpinBox. setMaximum ( max ) ¶

参数

max – double

另请参阅

maximum()

PySide2.QtWidgets.QDoubleSpinBox. setMinimum ( min ) ¶

参数

min – double

另请参阅

minimum()

PySide2.QtWidgets.QDoubleSpinBox. setPrefix ( prefix ) ¶

参数

prefix – unicode

另请参阅

prefix()

PySide2.QtWidgets.QDoubleSpinBox. setRange ( min , max ) ¶

参数

• min – double

• max – double

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)
											

相当于：

setMinimum(minimum)
setMaximum(maximum)
											

另请参阅

minimum maximum

PySide2.QtWidgets.QDoubleSpinBox. setSingleStep ( val ) ¶

参数

val – double

另请参阅

singleStep()

PySide2.QtWidgets.QDoubleSpinBox. setStepType ( stepType ) ¶

参数

stepType – StepType

Sets the step type for the spin box to stepType , which is single step or adaptive decimal step.

Adaptive decimal step means that the step size will continuously be adjusted to one power of ten below the current value . So when the value is 1100, the step is set to 100, so stepping up once increases it to 1200. For 1200 stepping up takes it to 1300. For negative values, stepping down from -1100 goes to -1200.

It also works for any decimal values, 0.041 is increased to 0.042 by stepping once.

Step direction is taken into account to handle edges cases, so that stepping down from 100 takes the value to 99 instead of 90. Thus a step up followed by a step down – or vice versa – always lands on the starting value; 99 -> 100 -> 99.

Setting this will cause the spin box to disregard the value of singleStep , although it is preserved so that singleStep comes into effect if adaptive decimal step is later turned off.

另请参阅

stepType()

PySide2.QtWidgets.QDoubleSpinBox. setSuffix ( suffix ) ¶

参数

suffix – unicode

另请参阅

suffix()

PySide2.QtWidgets.QDoubleSpinBox. setValue ( val ) ¶

参数

val – double

另请参阅

value()

PySide2.QtWidgets.QDoubleSpinBox. singleStep ( ) ¶

返回类型

double

另请参阅

setSingleStep()

PySide2.QtWidgets.QDoubleSpinBox. stepType ( ) ¶

返回类型

StepType

另请参阅

setStepType()

PySide2.QtWidgets.QDoubleSpinBox. suffix ( ) ¶

返回类型

unicode

另请参阅

setSuffix()

PySide2.QtWidgets.QDoubleSpinBox. textChanged ( arg__1 ) ¶

参数

arg__1 – unicode

PySide2.QtWidgets.QDoubleSpinBox. textFromValue ( val ) ¶

参数

val – double

返回类型

unicode

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 locale() .toString( value , QLatin1Char (‘f’), decimals() ) and will remove the thousand separator unless setGroupSeparatorShown() is set. Reimplementations may return anything.

注意： 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() .

另请参阅

valueFromText() groupSeparator()

PySide2.QtWidgets.QDoubleSpinBox. value ( ) ¶

返回类型

double

另请参阅

setValue()

PySide2.QtWidgets.QDoubleSpinBox. valueChanged ( arg__1 ) ¶

参数

arg__1 – unicode

注意

此函数被弃用。

PySide2.QtWidgets.QDoubleSpinBox. valueChanged ( arg__1 ) ¶

参数

arg__1 – double

PySide2.QtWidgets.QDoubleSpinBox. valueFromText ( text ) ¶

参数

text – unicode

返回类型

double

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.

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

另请参阅

textFromValue() validate()