内容

• 公共类型
• 特性
• 公共函数
• 重实现公共函数
• 详细描述

QDoubleValidator 类

The QDoubleValidator class provides range checking of floating-point numbers. 更多...

头：	#include <QDoubleValidator>
qmake:	QT += gui
实例化：	DoubleValidator
继承：	QValidator

• 所有成员列表，包括继承成员

公共类型

enum	Notation { StandardNotation, ScientificNotation }

特性

• bottom : double
• decimals : int
• notation : Notation
• top : double

• 1 特性继承自 QObject

公共函数

	QDoubleValidator (QObject * parent = Q_NULLPTR)
	QDoubleValidator (double bottom , double top , int decimals , QObject * parent = Q_NULLPTR)
	~QDoubleValidator ()
double	bottom () const
int	decimals () const
Notation	notation () const
void	setBottom ( double )
void	setDecimals ( int )
void	setNotation ( Notation )
virtual void	setRange (double minimum , double maximum , int decimals = 0)
void	setTop ( double )
double	top () const

重实现公共函数

virtual QValidator::State

validate (QString & input , int & pos ) const

• 4 公共函数继承自 QValidator
• 32 公共函数继承自 QObject

额外继承成员

• 1 公共槽继承自 QObject
• 1 信号继承自 QValidator
• 2 信号继承自 QObject
• 11 静态公共成员继承自 QObject
• 9 保护函数继承自 QObject

详细描述

The QDoubleValidator class provides range checking of floating-point numbers.

QDoubleValidator provides an upper bound, a lower bound, and a limit on the number of digits after the decimal point. It does not provide a fixup () 函数。

You can set the acceptable range in one call with setRange (), or with setBottom () 和 setTop (). Set the number of decimal places with setDecimals ()。 validate () function returns the validation state.

QDoubleValidator uses its locale () to interpret the number. For example, in the German locale, "1,234" will be accepted as the fractional number 1.234. In Arabic locales, QDoubleValidator will accept Arabic digits.

注意： The QLocale::NumberOptions 设置在 locale () 还会影响数字的解释方式。例如，由于 QLocale::RejectGroupSeparator 默认未设置，验证器将接受组分隔符。因此推荐使用 QLocale::toDouble () 获得数值。

另请参阅 QIntValidator , QRegExpValidator , QLocale::toDouble ()，和 行编辑范例 .

成员类型文档编制

enum QDoubleValidator:: Notation

This enum defines the allowed notations for entering a double.

常量	值	描述
QDoubleValidator::StandardNotation	0	The string is written as a standard number (i.e. 0.015).
QDoubleValidator::ScientificNotation	1	The string is written in scientific form. It may have an exponent part(i.e. 1.5E-2).

该枚举在 Qt 4.3 引入或被修改。

特性文档编制

bottom : double

This property holds the validator's minimum acceptable value

By default, this property contains a value of -infinity.

访问函数：

double	bottom () const
void	setBottom ( double )

另请参阅 setRange ().

decimals : int

This property holds the validator's maximum number of digits after the decimal point

By default, this property contains a value of 1000.

访问函数：

int	decimals () const
void	setDecimals ( int )

另请参阅 setRange ().

notation : Notation

This property holds the notation of how a string can describe a number

默认情况下，此特性被设为 ScientificNotation .

该特性在 Qt 4.3 引入。

访问函数：

Notation	notation () const
void	setNotation ( Notation )

另请参阅 Notation .

top : double

This property holds the validator's maximum acceptable value

By default, this property contains a value of infinity.

访问函数：

double	top () const
void	setTop ( double )

另请参阅 setRange ().

成员函数文档编制

QDoubleValidator:: QDoubleValidator ( QObject * parent = Q_NULLPTR)

Constructs a validator object with a parent object that accepts any double.

QDoubleValidator:: QDoubleValidator ( double bottom , double top , int decimals , QObject * parent = Q_NULLPTR)

Constructs a validator object with a parent object. This validator will accept doubles from bottom to top inclusive, with up to decimals digits after the decimal point.

QDoubleValidator:: ~QDoubleValidator ()

销毁验证器。

[虚拟] void QDoubleValidator:: setRange ( double minimum , double maximum , int decimals = 0)

Sets the validator to accept doubles from minimum to maximum inclusive, with at most decimals digits after the decimal point.

[虚拟] QValidator::State QDoubleValidator:: validate ( QString & input , int & pos ) const

重实现自 QValidator::validate ().

返回 Acceptable 若字符串 input contains a double that is within the valid range and is in the correct format.

返回 中间体 if input contains a double that is outside the range or is in the wrong format; e.g. with too many digits after the decimal point or is empty.

返回 Invalid 若 input is not a double.

Note: If the valid range consists of just positive doubles (e.g. 0.0 to 100.0) and input is a negative double then Invalid 被返回。若 notation () 被设为 StandardNotation , and the input contains more digits before the decimal point than a double in the valid range may have, Invalid 被返回。若 notation () 是 ScientificNotation , and the input is not in the valid range, 中间体 is returned. The value may yet become valid by changing the exponent.

默认情况下， pos 参数并未用于此验证器。