Tuple<T1,T2,T3,T4,T5,T6,T7,TRest>.Item4 Vlastnost
Definice
Důležité
Některé informace platí pro předběžně vydaný produkt, který se může zásadně změnit, než ho výrobce nebo autor vydá. Microsoft neposkytuje žádné záruky, výslovné ani předpokládané, týkající se zde uváděných informací.
Získá hodnotu čtvrté komponenty aktuálního Tuple<T1,T2,T3,T4,T5,T6,T7,TRest> objektu.
public:
property T4 Item4 { T4 get(); };
public T4 Item4 { get; }
member this.Item4 : 'T4
Public ReadOnly Property Item4 As T4
Hodnota vlastnosti
- T4
Hodnota čtvrté komponenty aktuálního Tuple<T1,T2,T3,T4,T5,T6,T7,TRest> objektu.
Příklady
Následující příklad vytvoří objekt řazené kolekce 17 členů obsahující data o populaci města Detroit ve státě Michigan mezi lety 1860 a 2000. Čtvrtá součást řazené kolekce členů 17 je populace v roce 1870. Příklad používá Item4 vlastnost k zobrazení hodnoty základního souboru a k výpočtu roční míry změny populace mezi 1870 a 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 %
Poznámky
Typ komponenty můžete dynamicky určit Item4 jedním ze dvou způsobů:
Voláním metody na
GetType
hodnotu, která je vrácena Item4 vlastností.Načtením objektu Type Tuple<T1,T2,T3,T4,T5,T6,T7,TRest> , který představuje objekt, a načtením čtvrtého prvku z pole, které je vráceno jeho Type.GetGenericArguments metodou.