Tuple<T1,T2,T3,T4,T5,T6,T7,TRest>.Item4 Proprietà

Riferimento

Definizione

Spazio dei nomi:: System

Assembly:: System.Runtime.dll

Assembly:: mscorlib.dll

Assembly:: netstandard.dll

Importante

Alcune informazioni sono relative alla release non definitiva del prodotto, che potrebbe subire modifiche significative prima della release definitiva. Microsoft non riconosce alcuna garanzia, espressa o implicita, in merito alle informazioni qui fornite.

Ottiene il valore del quarto componente dell'oggetto Tuple<T1,T2,T3,T4,T5,T6,T7,TRest> corrente.

public:
 property T4 Item4 { T4 get(); };

public T4 Item4 { get; }

member this.Item4 : 'T4

Public ReadOnly Property Item4 As T4

Valore della proprietà

T4

Valore del quarto componente dell'oggetto Tuple<T1,T2,T3,T4,T5,T6,T7,TRest> corrente.

Esempio

Nell'esempio seguente viene creato un oggetto a 17 tuple che contiene i dati sulla popolazione per la città di Detroit, Michigan, dal 1860 al 2000. Il quarto componente della tupla a 17 è la popolazione nel 1870. Nell'esempio viene utilizzata la Item4 proprietà per visualizzare il valore della popolazione e per calcolare la variazione annuale della popolazione tra 1870 e 1880.

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

È possibile determinare dinamicamente il tipo del Item4 componente in uno dei due modi seguenti:

Chiamando il GetType metodo sul valore restituito dalla Item4 proprietà .
Recuperando l'oggetto Type che rappresenta l'oggetto Tuple<T1,T2,T3,T4,T5,T6,T7,TRest> e recuperando il quarto elemento dalla matrice restituita dal relativo Type.GetGenericArguments metodo.

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