Tuple<T1,T2,T3,T4,T5>.Item1 属性

定义

命名空间:

System

程序集:

System.Runtime.dll

程序集:

mscorlib.dll

程序集:

netstandard.dll

获取当前 Tuple<T1,T2,T3,T4,T5> 对象的第一个分量的值。

public:
 property T1 Item1 { T1 get(); };

public T1 Item1 { get; }

member this.Item1 : 'T1

Public ReadOnly Property Item1 As T1

属性值

T1

当前 Tuple<T1,T2,T3,T4,T5> 对象的第一个分量的值。

示例

以下示例定义一个对象数组Tuple<T1,T2,T3,T4,T5>，其组件包含美国中的状态名称、1990 年和 2000 年的状态名称、10 年期间的人口变化以及总体百分比变化。 然后循环访问数组，并在元组中显示每个组件的值。

using System;

public class Example
{
   public static void Main()
   {
      // Define array of tuples reflecting population change by state, 1990-2000.
      Tuple<string, int, int, int, double>[] statesData = 
         { Tuple.Create("California", 29760021, 33871648, 4111627, 13.8), 
           Tuple.Create("Illinois", 11430602, 12419293, 988691, 8.6), 
           Tuple.Create("Washington", 4866692, 5894121, 1027429, 21.1) };

      // Display the items of each tuple
      Console.WriteLine("{0,-12}{1,18}{2,18}{3,15}{4,12}\n", "State", 
                        "Population 1990", "Population 2000", "Change", 
                        "% Change");
      foreach(Tuple<string, int, int, int, double> stateData in statesData)
         Console.WriteLine("{0,-12}{1,18:N0}{2,18:N0}{3,15:N0}{4,12:P1}", 
                           stateData.Item1, stateData.Item2, 
                           stateData.Item3, stateData.Item4, stateData.Item5/100);      
   }
}
// The example displays the following output:
//    State          Population 1990   Population 2000         Change    % Change
//    
//    California          29,760,021        33,871,648      4,111,627      13.8 %
//    Illinois            11,430,602        12,419,293        988,691       8.6 %
//    Washington           4,866,692         5,894,121      1,027,429      21.1 %

open System

// Define array of tuples reflecting population change by state, 1990-2000.
let statesData = 
    [| Tuple.Create("California", 29760021, 33871648, 4111627, 13.8)
       Tuple.Create("Illinois", 11430602, 12419293, 988691, 8.6)
       Tuple.Create("Washington", 4866692, 5894121, 1027429, 21.1) |]

// Display the items of each tuple
printfn "%-12s%18s%18s%15s%12s\n" "State" "Population 1990" "Population 2000" "Change" "% Change"
for stateData in statesData do
    printfn $"{stateData.Item1,-12}{stateData.Item2,18:N0}{stateData.Item3,18:N0}{stateData.Item4,15:N0}{stateData.Item5,12:P1}"
// The example displays the following output:
//    State          Population 1990   Population 2000         Change    % Change
//    
//    California          29,760,021        33,871,648      4,111,627      13.8 %
//    Illinois            11,430,602        12,419,293        988,691       8.6 %
//    Washington           4,866,692         5,894,121      1,027,429      21.1 %

Module Example
   Public Sub Main()
      ' Define array of tuples reflecting population change by state, 1990-2000.
      Dim statesData() = 
          { Tuple.Create("California", 29760021, 33871648, 4111627, 13.8), 
            Tuple.Create("Illinois", 11430602, 12419293, 988691, 8.6), 
            Tuple.Create("Washington", 4866692, 5894121, 1027429, 21.1) }
      ' Display the items of each tuple
      Console.WriteLine("{0,-12}{1,18}{2,18}{3,15}{4,12}", "State", "Population 1990", _
                        "Population 2000", "Change", "% Change")
      Console.WriteLine()
      For Each stateData As Tuple(Of String, Integer, Integer, Integer, Double) In statesData
         Console.WriteLine("{0,-12}{1,18:N0}{2,18:N0}{3,15:N0}{4,12:P1}", _
                           stateData.Item1, stateData.Item2, _
                           stateData.Item3, stateData.Item4, stateData.Item5/100)      
      Next                                                                    
   End Sub
End Module
' The example displays the following output:
'    State          Population 1990   Population 2000         Change    % Change
'    
'    California          29,760,021        33,871,648      4,111,627      13.8 %
'    Illinois            11,430,602        12,419,293        988,691       8.6 %
'    Washington           4,866,692         5,894,121      1,027,429      21.1 %

注解

可以通过以下两种方式之一动态确定组件的类型 Item1 ：

• 通过对属性返回Item1的值调用GetType方法。

• 通过检索 Type 表示 Tuple<T1,T2,T3,T4,T5> 对象的对象，并从其 Type.GetGenericArguments 方法返回的数组中检索第一个元素。