Tuple<T1,T2,T3,T4>.Item1 属性

定义

命名空间:

System

程序集:

System.Runtime.dll

Source:

Tuple.cs

获取当前 Tuple<T1,T2,T3,T4> 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> 对象的第一个分量的值。

示例

下面的示例定义对象的数组 Tuple<T1,T2,T3,T4> ，其组件包含城市名称、一年中的一个月以及该月的平均高温和低温。 然后，它会检索并显示每个组件的值。

using System;
using System.Globalization;

public class Example
{
   public static void Main()
   {
      Tuple<string, int, double, double>[] temperatures = 
            { Tuple.Create("New York, NY", 4, 61.0, 43.0),
              Tuple.Create("Chicago, IL", 2, 34.0, 18.0), 
              Tuple.Create("Newark, NJ", 4, 61.0, 43.0),
              Tuple.Create("Boston, MA", 6, 77.0, 59.0),
              Tuple.Create("Detroit, MI", 9, 74.0, 53.0),
              Tuple.Create("Minneapolis, MN", 8, 81.0, 61.0) }; 
      // Display the array of 4-tuple objects.
      Console.WriteLine("{0,41}", "Temperatures");
      Console.WriteLine("{0,-20} {1,5}    {2,4}  {3,4}\n", 
                        "City", "Month", "High", "Low");
      foreach (var temperature in temperatures)
         Console.WriteLine("{0,-20} {1,5}    {2,4:N1}  {3,4:N1}", 
                           temperature.Item1, 
                           DateTimeFormatInfo.CurrentInfo.GetAbbreviatedMonthName(temperature.Item2 - 1), 
                           temperature.Item3, temperature.Item4);
   }
}
// The example displays the following output:
//                                    Temperatures
//       City                 Month    High   Low
//       
//       New York, NY           Mar    61.0  43.0
//       Chicago, IL            Jan    34.0  18.0
//       Newark, NJ             Mar    61.0  43.0
//       Boston, MA             May    77.0  59.0
//       Detroit, MI            Aug    74.0  53.0
//       Minneapolis, MN        Jul    81.0  61.0

open System
open System.Globalization

let temperatures = 
    [| Tuple.Create("New York, NY", 4, 61.0, 43.0)
       Tuple.Create("Chicago, IL", 2, 34.0, 18.0) 
       Tuple.Create("Newark, NJ", 4, 61.0, 43.0)
       Tuple.Create("Boston, MA", 6, 77.0, 59.0)
       Tuple.Create("Detroit, MI", 9, 74.0, 53.0)
       Tuple.Create("Minneapolis, MN", 8, 81.0, 61.0) |] 

// Display the array of 4-tuple objects.
printfn "%41s" "Temperatures"
printfn "%-20s %5s    %4s  %4s\n" "City" "Month" "High" "Low"
for temperature in temperatures do
    printfn $"{temperature.Item1,-20} {DateTimeFormatInfo.CurrentInfo.GetAbbreviatedMonthName(temperature.Item2 - 1),5}    {temperature.Item3,4:N1}  {temperature.Item4,4:N1}" 
// The example displays the following output:
//                                    Temperatures
//       City                 Month    High   Low
//       
//       New York, NY           Mar    61.0  43.0
//       Chicago, IL            Jan    34.0  18.0
//       Newark, NJ             Mar    61.0  43.0
//       Boston, MA             May    77.0  59.0
//       Detroit, MI            Aug    74.0  53.0
//       Minneapolis, MN        Jul    81.0  61.0

Imports System.Globalization

Module Example
   Public Sub Main()
      Dim temperatures() = 
             { Tuple.Create("New York, NY", 4, 61, 43), _
               Tuple.Create("Chicago, IL", 2, 34, 18), _ 
               Tuple.Create("Newark, NJ", 4, 61, 43), _
               Tuple.Create("Boston, MA", 6, 77, 59), _
               Tuple.Create("Detroit, MI", 9, 74, 53), _
               Tuple.Create("Minneapolis, MN", 8, 81, 61) } 
      ' Display the array of 4-tuples.
      Console.WriteLine("{0,41}", "Temperatures")
      Console.WriteLine("{0,-20} {1,5}    {2,4}  {3,4}", 
                        "City", "Month", "High", "Low")
      Console.WriteLine()
      For Each temperature In temperatures
         Console.WriteLine("{0,-20} {1,5}    {2,4:N1}  {3,4:N1}", 
                           temperature.Item1, 
                           DateTimeFormatInfo.CurrentInfo.GetAbbreviatedMonthName(temperature.Item2 - 1), 
                           temperature.Item3, temperature.Item4)
      Next
   End Sub
End Module
' The example displays the following output:
'                                    Temperatures
'       City                 Month    High   Low
'       
'       New York, NY           Mar    61.0  43.0
'       Chicago, IL            Jan    34.0  18.0
'       Newark, NJ             Mar    61.0  43.0
'       Boston, MA             May    77.0  59.0
'       Detroit, MI            Aug    74.0  53.0
'       Minneapolis, MN        Jul    81.0  61.0

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 Type 检索表示 Tuple<T1,T2,T3,T4> 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。