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Tuple<T1,T2,T3,T4,T5,T6,T7,TRest>.Rest Proprietà

Definizione

Ottiene i componenti restanti dell'oggetto Tuple<T1,T2,T3,T4,T5,T6,T7,TRest> corrente.

public:
 property TRest Rest { TRest get(); };
public TRest Rest { get; }
member this.Rest : 'Rest
Public ReadOnly Property Rest As TRest

Valore della proprietà

TRest

Valore dei componenti restanti dell'oggetto Tuple<T1,T2,T3,T4,T5,T6,T7,TRest> corrente.

Esempio

Nell'esempio seguente viene creato un oggetto da 17 tuple che contiene i dati della popolazione per la città di Detroit, nel Michigan, dal 1860 al 2000. Il settimo componente della tupla 17 è la popolazione nel 1900. Nell'esempio viene utilizzata la Rest proprietà per recuperare i valori dell'ottavo fino al 11° componente e usa la Rest proprietà dell'oggetto annidato Tuple<T1,T2,T3,T4,T5,T6,T7,TRest> per recuperare i valori dei componenti rimanenti.

using System;

class Example
{
    static void Main(string[] args)
    {
        Tuple<int, int, int> from1980 = Tuple.Create(1203339, 1027974, 951270);
        var from1910 = new Tuple<int, int, int, int, int, int, int, Tuple<int, int, int>> 
            (465766, 993078, 1568622, 1623452, 1849568, 1670144, 1511462, from1980);
        var population = new Tuple<string, int, int, int, int, int, int,
            Tuple<int, int, int, int, int, int, int, Tuple<int, int, int>>> 
            ("Detroit", 1860, 45619, 79577, 116340, 205876, 285704, from1910);

        Console.WriteLine("Population of {0}", population.Item1);
        Console.WriteLine();
        Console.WriteLine("{0,5}  {1,14}  {2,10}", "Year", "Population", "Change");

        int year = population.Item2;
        ShowPopulation(year, population.Item3);
        year += 10;
        ShowPopulationChange(year, population.Item4, population.Item3);
        year += 10;
        ShowPopulationChange(year, population.Item5, population.Item4);
        year += 10;
        ShowPopulationChange(year, population.Item6, population.Item5);
        year += 10;
        ShowPopulationChange(year, population.Item7, population.Item6);
        year += 10;
        ShowPopulationChange(year, population.Rest.Item1, population.Item7);
        year += 10;
        ShowPopulationChange(year, population.Rest.Item2, population.Rest.Item1);
        year += 10;
        ShowPopulationChange(year, population.Rest.Item3, population.Rest.Item2);
        year += 10;
        ShowPopulationChange(year, population.Rest.Item4, population.Rest.Item3);
        year += 10;
        ShowPopulationChange(year, population.Rest.Item5, population.Rest.Item4);
        year += 10;
        ShowPopulationChange(year, population.Rest.Item6, population.Rest.Item5);
        year += 10;
        ShowPopulationChange(year, population.Rest.Item7, population.Rest.Item6);
        year += 10;
        ShowPopulationChange(year, population.Rest.Rest.Item1, population.Rest.Item7);
        year += 10;
        ShowPopulationChange(year, population.Rest.Rest.Item2, population.Rest.Rest.Item1);
        year += 10;
        ShowPopulationChange(year, population.Rest.Rest.Item3, population.Rest.Rest.Item2);
    }

    private static void ShowPopulationChange(int year, int newPopulation, int oldPopulation)
    {
        Console.WriteLine("{0,5}  {1,14:N0}  {2,10:P2}", year, newPopulation,
                          ((double)(newPopulation - oldPopulation) / oldPopulation) / 10);
    }

    private static void ShowPopulation(int year, int newPopulation)
    {
        Console.WriteLine("{0,5}  {1,14:N0}  {2,10:P2}", year, newPopulation, "n/a");
    }
}
// The example displays the following output:
//
//    Population of Detroit
//    Year      Population      Change
//    1860          45,619         n/a
//    1870          79,577      7.44 %
//    1880         116,340      4.62 %
//    1890         205,876      7.70 %
//    1900         285,704      3.88 %
//    1910         465,766      6.30 %
//    1920         993,078     11.32 %
//    1930       1,568,622      5.80 %
//    1940       1,623,452      0.35 %
//    1950       1,849,568      1.39 %
//    1960       1,670,144     -0.97 %
//    1970       1,511,462     -0.95 %
//    1980       1,203,339     -2.04 %
//    1990       1,027,974     -1.46 %
//    2000         951,270     -0.75 %
let showPopulation year newPopulation =
    printfn $"""{year,5}  {newPopulation,14:N0}  {"n/a",10:P2}"""

let showPopulationChange year newPopulation oldPopulation =
    printfn $"{year,5}  {newPopulation,14:N0}  {(double (newPopulation - oldPopulation) / oldPopulation) / 10.,10:P2}"

let from1980 = Tuple.Create(1203339, 1027974, 951270)
let from1910 = new Tuple<int, int, int, int, int, int, int, Tuple<int, int, int>>(465766, 993078, 1568622, 1623452, 1849568, 1670144, 1511462, from1980)
let population = new Tuple<string, int, int, int, int, int, int, Tuple<int, int, int, int, int, int, int, Tuple<int, int, int>>>("Detroit", 1860, 45619, 79577, 116340, 205876, 285704, from1910)
printfn $"Population of {population.Item1}\n"
printfn "%5s  %14s  %10s" "Year" "Population" "Change"

do
    let year = population.Item2
    showPopulation year population.Item3
    let year = year + 10
    showPopulationChange year population.Item4 population.Item3
    let year = year + 10
    showPopulationChange year population.Item5 population.Item4
    let year = year + 10
    showPopulationChange year population.Item6 population.Item5
    let year = year + 10
    showPopulationChange year population.Item7 population.Item6
    let year = year + 10
    showPopulationChange year population.Rest.Item1 population.Item7
    let year = year + 10
    showPopulationChange year population.Rest.Item2 population.Rest.Item1
    let year = year + 10
    showPopulationChange year population.Rest.Item3 population.Rest.Item2
    let year = year + 10
    showPopulationChange year population.Rest.Item4 population.Rest.Item3
    let year = year + 10
    showPopulationChange year population.Rest.Item5 population.Rest.Item4
    let year = year + 10
    showPopulationChange year population.Rest.Item6 population.Rest.Item5
    let year = year + 10
    showPopulationChange year population.Rest.Item7 population.Rest.Item6
    let year = year + 10
    showPopulationChange year population.Rest.Rest.Item1 population.Rest.Item7
    let year = year + 10
    showPopulationChange year population.Rest.Rest.Item2 population.Rest.Rest.Item1
    let year = year + 10
    showPopulationChange year population.Rest.Rest.Item3 population.Rest.Rest.Item2

// The example displays the following output:
//
//    Population of Detroit
//    Year      Population      Change
//    1860          45,619         n/a
//    1870          79,577      7.44 %
//    1880         116,340      4.62 %
//    1890         205,876      7.70 %
//    1900         285,704      3.88 %
//    1910         465,766      6.30 %
//    1920         993,078     11.32 %
//    1930       1,568,622      5.80 %
//    1940       1,623,452      0.35 %
//    1950       1,849,568      1.39 %
//    1960       1,670,144     -0.97 %
//    1970       1,511,462     -0.95 %
//    1980       1,203,339     -2.04 %
//    1990       1,027,974     -1.46 %
//    2000         951,270     -0.75 %
Module Example
    Sub Main()
        Dim from1980 As Tuple(Of Integer, Integer, Integer) =
            Tuple.Create(1203339, 1027974, 951270)
        Dim from1910 As New Tuple(Of Integer, Integer, Integer, Integer, Integer, Integer, Integer, _
            Tuple(Of Integer, Integer, Integer)) _
            (465766, 993078, 1568622, 1623452, 1849568, 1670144, 1511462, from1980)
        Dim population As New Tuple(Of String, Integer, Integer, Integer, Integer, Integer, Integer, _ 
            Tuple(Of Integer, Integer, Integer, Integer, Integer, Integer, Integer, Tuple(Of Integer, Integer, Integer))) _
            ("Detroit", 1860, 45619, 79577, 116340, 205876, 285704, from1910)

        Console.WriteLine("Population of {0}", population.Item1)
        Console.WriteLine()
        Console.WriteLine("{0,5}  {1,14}  {2,10}", "Year", "Population", "Change")

        Dim year As Integer = population.Item2
        ShowPopulation(year, population.Item3)
        year += 10
        ShowPopulationChange(year, population.Item4, population.Item3)
        year += 10
        ShowPopulationChange(year, population.Item5, population.Item4)
        year += 10
        ShowPopulationChange(year, population.Item6, population.Item5)
        year += 10
        ShowPopulationChange(year, population.Item7, population.Item6)
        year += 10
        ShowPopulationChange(year, population.Rest.Item1, population.Item7)
        year += 10
        ShowPopulationChange(year, population.Rest.Item2, population.Rest.Item1)
        year += 10
        ShowPopulationChange(year, population.Rest.Item3, population.Rest.Item2)
        year += 10
        ShowPopulationChange(year, population.Rest.Item4, population.Rest.Item3)
        year += 10
        ShowPopulationChange(year, population.Rest.Item5, population.Rest.Item4)
        year += 10
        ShowPopulationChange(year, population.Rest.Item6, population.Rest.Item5)
        year += 10
        ShowPopulationChange(year, population.Rest.Item7, population.Rest.Item6)
        year += 10
        ShowPopulationChange(year, population.Rest.Rest.Item1, population.Rest.Item7)
        year += 10
        ShowPopulationChange(year, population.Rest.Rest.Item2, population.Rest.Rest.Item1)
        year += 10
        ShowPopulationChange(year, population.Rest.Rest.Item3, population.Rest.Rest.Item2)
    End Sub

    Private Sub ShowPopulationChange(ByVal year As Integer, ByVal newPopulation As Integer, ByVal oldPopulation As Integer)
        Console.WriteLine("{0,5}  {1,14:N0}  {2,10:P2}", year, newPopulation,
                          (newPopulation - oldPopulation) / oldPopulation / 10)
    End Sub

    Private Sub ShowPopulation(ByVal year As Integer, ByVal newPopulation As Integer)
        Console.WriteLine("{0,5}  {1,14:N0}  {2,10:P2}", year, newPopulation, "n/a")
    End Sub
End Module
' The example displays the following output:
'
'    Population of Detroit
'    Year      Population      Change
'    1860          45,619         n/a
'    1870          79,577      7.44 %
'    1880         116,340      4.62 %
'    1890         205,876      7.70 %
'    1900         285,704      3.88 %
'    1910         465,766      6.30 %
'    1920         993,078     11.32 %
'    1930       1,568,622      5.80 %
'    1940       1,623,452      0.35 %
'    1950       1,849,568      1.39 %
'    1960       1,670,144     -0.97 %
'    1970       1,511,462     -0.95 %
'    1980       1,203,339     -2.04 %
'    1990       1,027,974     -1.46 %
'    2000         951,270     -0.75 %

Commenti

La Rest proprietà restituisce un oggetto annidato che consente l'accesso all'ottavo Tuple anche se nn componenti della tupla. A seconda del numero totale di componenti nella tupla, è possibile recuperare i valori dell'ottavo al 4° componente dalle proprietà dell'oggetto Item1Item7 annidatoTuple. È quindi possibile usare la Rest proprietà di un oggetto annidato per recuperare l'oggetto Tuple a livello successivo di annidamentoTuple<T1,T2,T3,T4,T5,T6,T7,TRest>.

È possibile determinare dinamicamente il numero di componenti in un oggetto annidato restituito Tuple dalla Rest proprietà estraendo la cifra dal nome del tipo. Nell'esempio seguente viene illustrato questo concetto.

Imports System.Reflection

Module Example
    Sub Main()
        Dim from1980 As Tuple(Of Integer, Integer, Integer) =
            Tuple.Create(1203339, 1027974, 951270)
        Dim from1910 As New Tuple(Of Integer, Integer, Integer, Integer, Integer, Integer, Integer, _
            Tuple(Of Integer, Integer, Integer)) _
            (465766, 993078, 1568622, 1623452, 1849568, 1670144, 1511462, from1980)
        Dim population As New Tuple(Of String, Integer, Integer, Integer, Integer, Integer, Integer, _ 
            Tuple(Of Integer, Integer, Integer, Integer, Integer, Integer, Integer, Tuple(Of Integer, Integer, Integer))) _
            ("Detroit", 1860, 45619, 79577, 116340, 205876, 285704, from1910)
      
        ShowComponentCount(population)
   End Sub
   
   Private Sub ShowComponentCount(tuple As Object) 
      Static ctr As Integer = 0
      Static totalComponents As Integer = 0
      Dim components As Integer = 0
      
      ctr += 1
      Dim name As String = tuple.GetType().Name
      components += Int32.Parse(name.Substring(name.IndexOf("`") + 1))
      If components = 8 Then
         totalComponents += 7
         Console.WriteLine("The tuple at level {0} has 7 components.", ctr)
         ShowComponentCount(tuple.Rest)
      Else
         totalComponents += components
         Console.WriteLine("The tuple at level {0} has {1} components.", 
                           ctr, components)
         Console.WriteLine("Total components in tuple: {0}", totalComponents)
      End If      
   End Sub        
End Module
' The example displays the following output:
'       The tuple at level 1 has 7 components.
'       The tuple at level 2 has 7 components.
'       The tuple at level 3 has 3 components.
'       Total components in tuple: 17

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