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IComparable<T>.CompareTo Método

Compara o objeto atual com outro objeto do mesmo tipo.

Namespace:  System
Assembly:  mscorlib (em mscorlib. dll)

int CompareTo(
	T other
)

Parâmetros

other
Tipo: T
Um objeto para comparar com esse objeto.

Valor de retorno

Tipo: System.Int32
A 32-bit that the relativo indicates número inteiro assinado Ordem of the Objects being compared.O valor de retorno tem os seguintes significados:

Value (Valor)

Significado

Menor do que zero

This object is less than the other parameter.

Zero

This object is equal to other.

Maior que zero

This object is greater than other.

Este método é apenas uma definição e deve ser implementado por uma classe específica ou um tipo valor para ter efeito. The Meaning of the comparisons, " Menos than, " "equal to", and "greater than," Depends on the particular.

By definition, any object compares greater than null, and two null references compare equal to each other.

OBSERVAÇÕES PARA Implementers:

For Objects A, B, and C, the seguinte must be Verdadeiro:

A.CompareTo(A) is required to return zero.

If A.CompareTo(B) returns zero, then B.CompareTo(A) is required to return zero.

If A.CompareTo(B) returns zero and B.CompareTo(C) returns zero, then A.CompareTo(C) is required to return zero.

If A.CompareTo(B) returns a value other than zero, then B.CompareTo(A) is required to return a value of the opposite sign.

If A.CompareTo(B) returns a value x that is not equal to zero, and B.CompareTo(C) returns a value y of the same sign as x, then A.CompareTo(C) is required to return a value of the same sign as x and y.

Observações para chamadores:

Use the CompareTo method to determine the ordering of instances of a class.

The following code example illustrates the implementation of IComparable for a simple Temperature object.The example creates a SortedList<TKey, TValue> collection of strings with Temperature object keys, and adds several pairs of temperatures and strings to the list out of sequence.The SortedList<TKey, TValue> collection uses the IComparable<T> implementation to sort the list entries, which are then displayed in order of increasing temperature.

using System;
using System.Collections.Generic;

public class Temperature : IComparable<Temperature>
{
    // Implement the CompareTo method. For the parameter type, Use 
    // the type specified for the type parameter of the generic 
    // IComparable interface. 
    //
    public int CompareTo(Temperature other)
    {
        // The temperature comparison depends on the comparison of the
        // the underlying Double values. Because the CompareTo method is
        // strongly typed, it is not necessary to test for the correct
        // object type.
        return m_value.CompareTo(other.m_value);
    }

    // The underlying temperature value.
    protected double m_value = 0.0;

    public double Celsius    
    {
        get
        {
            return m_value - 273.15;
        }
    }

    public double Kelvin    
    {
        get
        {
            return m_value;
        }
        set
        {
            if (value < 0.0)
            {
                throw new ArgumentException("Temperature cannot be less than absolute zero.");
            }
            else
            {
                m_value = value;
            }
        }
    }

    public Temperature(double degreesKelvin)
    {
        this.Kelvin = degreesKelvin;
    }
}

public class Example
{
    public static void Main()
    {
        SortedList<Temperature, string> temps = 
            new SortedList<Temperature, string>();

        // Add entries to the sorted list, out of order.
        temps.Add(new Temperature(2017.15), "Boiling point of Lead");
        temps.Add(new Temperature(0), "Absolute zero");
        temps.Add(new Temperature(273.15), "Freezing point of water");
        temps.Add(new Temperature(5100.15), "Boiling point of Carbon");
        temps.Add(new Temperature(373.15), "Boiling point of water");
        temps.Add(new Temperature(600.65), "Melting point of Lead");

        foreach( KeyValuePair<Temperature, string> kvp in temps )
        {
            Console.WriteLine("{0} is {1} degrees Celsius.", kvp.Value, kvp.Key.Celsius);
        }
    }
}

/* This code example produces the following output:

Absolute zero is -273.15 degrees Celsius.
Freezing point of water is 0 degrees Celsius.
Boiling point of water is 100 degrees Celsius.
Melting point of Lead is 327.5 degrees Celsius.
Boiling point of Lead is 1744 degrees Celsius.
Boiling point of Carbon is 4827 degrees Celsius.

*/


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