_Format _Unit _Value Ampere AngMinute AngSecond Bar Calorie Candela CentiMetre Coulomb CubicFoot DeciMetre Degree ElectronVolt Farad Foot Gauss getFormat getUnit getUserString getUserString getUserString getValue getValueAs GigaHertz GigaPascal Gon Gram Henry Hertz Hour Hundredweights Inch isDimensionless isQuantity isValid Joule Kelvin KiloAmpere KiloCalorie KiloElectronVolt KiloGram KiloHertz KiloJoule KiloMetre KiloNewton KiloNewtonPerMeter KiloOhm KiloPascal KiloSiemens KiloVolt KiloWatt KiloWattHour KMH KSI Liter MegaAmpere MegaElectronVolt MegaHertz MegaNewton MegaNewtonPerMeter MegaOhm MegaPascal MegaSiemens Metre MicroFarad MicroGram MicroHenry MicroKelvin MicroMetre MicroSiemens Mile MilePerHour MilliAmpere MilliBar MilliFarad MilliGram MilliHenry MilliJoule MilliKelvin MilliLiter MilliMetre MilliMole MilliNewton MilliNewtonPerMeter MilliSiemens MilliVolt MilliWatt Minute Mole MPH MPSI mTorr NanoFarad NanoHenry NanoMetre Newton NewtonMeter NewtonPerMeter Oersted Ohm operator* operator* operator+ operator+= operator- operator- operator-= operator/ operator/ operator< operator<= operator= operator== operator> operator>= Ounce parse Pascal PicoFarad Pound PoundForce pow pow PSI Quantity Quantity Quantity Quantity Radian Second setFormat setInvalid setUnit setValue Siemens SquareFoot Stone TeraHertz Tesla Thou Ton Torr Volt VoltAmpere VoltAmpereSecond Watt WattSecond Weber Yard yTorr ~Quantity

Quantity() [3/4] Quantity ( double  value, const Unit &  unit = Unit()  ) explicit 构造函数，初始化 Quantity 对象 使用指定的数值和单位初始化 Quantity 对象。 参数 [in] value 数值 [in] unit 单位（默认为空单位）