.NET 单位类，英寸到毫米
本文关键字：单位 NET | 更新日期: 2023-09-27 17:56:55
.NET 有单位转换类吗？我需要将英寸转换为毫米，反之亦然。
不，没有内置的。但是您可以简单地乘以或除以 25.4。
我以前处理过这个问题。我建议为距离设置两个类。一个具有英制度量，另一个具有公制度量。然后，您可以轻松地在它们之间来回转换，但需要注意的是，当您这样做时，您会失去精度。
下面是英制距离类的示例，以英寸作为基本测量单位。
public class ImperialDistance
{
public static readonly ImperialDistance Inch = new ImperialDistance(1.0);
public static readonly ImperialDistance Foot = new ImperialDistance(12.0);
public static readonly ImperialDistance Yard = new ImperialDistance(36.0);
public static readonly ImperialDistance Mile = new ImperialDistance(63360.0);
private double _inches;
public ImperialDistance(double inches)
{
_inches = inches;
}
public double ToInches()
{
return _inches;
}
public double ToFeet()
{
return _inches / Foot._inches;
}
public double ToYards()
{
return _inches / Yard._inches;
}
public double ToMiles()
{
return _inches / Mile._inches;
}
public MetricDistance ToMetricDistance()
{
return new MetricDistance(_inches * 0.0254);
}
public override int GetHashCode()
{
return _inches.GetHashCode();
}
public override bool Equals(object obj)
{
var o = obj as ImperialDistance;
if (o == null) return false;
return _inches.Equals(o._inches);
}
public static bool operator ==(ImperialDistance a, ImperialDistance b)
{
// If both are null, or both are same instance, return true
if (ReferenceEquals(a, b)) return true;
// if either one or the other are null, return false
if (ReferenceEquals(a, null) || ReferenceEquals(b, null)) return false;
// compare
return a._inches == b._inches;
}
public static bool operator !=(ImperialDistance a, ImperialDistance b)
{
return !(a == b);
}
public static ImperialDistance operator +(ImperialDistance a, ImperialDistance b)
{
if (a == null) throw new ArgumentNullException();
if (b == null) throw new ArgumentNullException();
return new ImperialDistance(a._inches + b._inches);
}
public static ImperialDistance operator -(ImperialDistance a, ImperialDistance b)
{
if (a == null) throw new ArgumentNullException();
if (b == null) throw new ArgumentNullException();
return new ImperialDistance(a._inches - b._inches);
}
public static ImperialDistance operator *(ImperialDistance a, ImperialDistance b)
{
if (a == null) throw new ArgumentNullException();
if (b == null) throw new ArgumentNullException();
return new ImperialDistance(a._inches * b._inches);
}
public static ImperialDistance operator /(ImperialDistance a, ImperialDistance b)
{
if (a == null) throw new ArgumentNullException();
if (b == null) throw new ArgumentNullException();
return new ImperialDistance(a._inches / b._inches);
}
}
下面是一个以米为基本单位的公制类：
public class MetricDistance
{
public static readonly MetricDistance Milimeter = new MetricDistance(0.001);
public static readonly MetricDistance Centimeter = new MetricDistance(0.01);
public static readonly MetricDistance Decimeter = new MetricDistance(0.1);
public static readonly MetricDistance Meter = new MetricDistance(1.0);
public static readonly MetricDistance Decameter = new MetricDistance(10.0);
public static readonly MetricDistance Hectometer = new MetricDistance(100.0);
public static readonly MetricDistance Kilometer = new MetricDistance(1000.0);
private double _meters;
public MetricDistance(double meters)
{
_meters = meters;
}
public double ToMilimeters()
{
return _meters / Milimeter._meters;
}
public double ToCentimeters()
{
return _meters / Centimeter._meters;
}
public double ToDecimeters()
{
return _meters / Decimeter._meters;
}
public double ToMeters()
{
return _meters;
}
public double ToDecameters()
{
return _meters / Decameter._meters;
}
public double ToHectometers()
{
return _meters / Hectometer._meters;
}
public double ToKilometers()
{
return _meters / Kilometer._meters;
}
public ImperialDistance ToImperialDistance()
{
return new ImperialDistance(_meters * 39.3701);
}
public override int GetHashCode()
{
return _meters.GetHashCode();
}
public override bool Equals(object obj)
{
var o = obj as MetricDistance;
if (o == null) return false;
return _meters.Equals(o._meters);
}
public static bool operator ==(MetricDistance a, MetricDistance b)
{
// If both are null, or both are same instance, return true
if (ReferenceEquals(a, b)) return true;
// if either one or the other are null, return false
if (ReferenceEquals(a, null) || ReferenceEquals(b, null)) return false;
return a._meters == b._meters;
}
public static bool operator !=(MetricDistance a, MetricDistance b)
{
return !(a == b);
}
public static MetricDistance operator +(MetricDistance a, MetricDistance b)
{
if (a == null) throw new ArgumentNullException("a");
if (b == null) throw new ArgumentNullException("b");
return new MetricDistance(a._meters + b._meters);
}
public static MetricDistance operator -(MetricDistance a, MetricDistance b)
{
if (a == null) throw new ArgumentNullException("a");
if (b == null) throw new ArgumentNullException("b");
return new MetricDistance(a._meters - b._meters);
}
public static MetricDistance operator *(MetricDistance a, MetricDistance b)
{
if (a == null) throw new ArgumentNullException("a");
if (b == null) throw new ArgumentNullException("b");
return new MetricDistance(a._meters * b._meters);
}
public static MetricDistance operator /(MetricDistance a, MetricDistance b)
{
if (a == null) throw new ArgumentNullException("a");
if (b == null) throw new ArgumentNullException("b");
return new MetricDistance(a._meters / b._meters);
}
}
这里有一个测试方法，可以举例说明用法。
[TestMethod]
public void _5in_Equals_12_7cm()
{
var inches = new ImperialDistance(5);
var cms = new MetricDistance(MetricDistance.Centimeter.ToMeters() * 12.7);
var calcCentimeters = Math.Round(inches.ToMetricDistance().ToCentimeters(), 2, MidpointRounding.AwayFromZero);
var calcInches = Math.Round(cms.ToImperialDistance().ToInches(), 2, MidpointRounding.AwayFromZero);
Assert.AreEqual(cms.ToCentimeters(), 12.7);
Assert.AreEqual(calcCentimeters, 12.7);
Assert.AreEqual(inches.ToInches(), 5);
Assert.AreEqual(calcInches, 5);
}
您还可以添加扩展方法：
public static MetricDistance Centimeters(this Int32 that)
{
return new MetricDistance(MetricDistance.Centimeter.ToMeters() * that);
}
[TestMethod]
public void _100cm_plus_300cm_equals_400cm()
{
Assert.AreEqual(100.Centimeters() + 300.Centimeters(), 400.Centimeters());
}
您可以将这种简单的策略用于重量、温度、液体测量等。
.NET Framework 没有这样的东西，但 F# 有度量单位。
不，框架中没有内置这样的单位转换。不过，应该很容易实现自己。
Csunits 是一个很好的 C# 度量单位库，请参见 https://github.com/cureos/csunits。它目前面向放射治疗，但您可以轻松添加自己的单位和数量。
不，你需要自己做一个，像这样：
public class Length
{
private const double MillimetersPerInch = 25.4;
private double _Millimeters;
public static Length FromMillimeters(double mm)
{
return new Length { _Millimeters = mm };
}
public static Length FromInch(double inch)
{
return new Length { _Millimeters = inch * MillimetersPerInch };
}
public double Inch { get { return _Millimeters / MillimetersPerInch; } }
public double Millimeters { get { return _Millimeters; } }
}
几年后，有很多Nuget包可以解决这个问题。其中之一是 https://github.com/angularsen/UnitsNet 它能够处理您想要的东西。
Length distance = Length.FromInch(15);
distance.Millimeters/ 60;
它还支持许多其他东西。