SortedList.GetKey(Int32) 方法

定义

命名空间:

System.Collections

程序集:

System.Collections.NonGeneric.dll

Source:

SortedList.cs

获取 SortedList 对象的指定索引处的键。

public:
 virtual System::Object ^ GetKey(int index);

public virtual object GetKey (int index);

abstract member GetKey : int -> obj
override this.GetKey : int -> obj

Public Overridable Function GetKey (index As Integer) As Object

参数

index

Int32

要获取的键的从零开始的索引。

返回

Object

SortedList 对象的指定索引处的键。

例外

ArgumentOutOfRangeException

index 不在 SortedList 对象的有效索引范围内。

示例

下面的代码示例演示如何获取 对象中的一个 SortedList 或所有键或值。

#using <system.dll>

using namespace System;
using namespace System::Collections;
int main()
{
   
   // Creates and initializes a new SortedList.
   SortedList^ mySL = gcnew SortedList;
   mySL->Add( 1.3, "fox" );
   mySL->Add( 1.4, "jumps" );
   mySL->Add( 1.5, "over" );
   mySL->Add( 1.2, "brown" );
   mySL->Add( 1.1, "quick" );
   mySL->Add( 1.0, "The" );
   mySL->Add( 1.6, "the" );
   mySL->Add( 1.8, "dog" );
   mySL->Add( 1.7, "lazy" );
   
   // Gets the key and the value based on the index.
   int myIndex = 3;
   Console::WriteLine( "The key   at index {0} is {1}.", myIndex, mySL->GetKey( myIndex ) );
   Console::WriteLine( "The value at index {0} is {1}.", myIndex, mySL->GetByIndex( myIndex ) );
   
   // Gets the list of keys and the list of values.
   IList^ myKeyList = mySL->GetKeyList();
   IList^ myValueList = mySL->GetValueList();
   
   // Prints the keys in the first column and the values in the second column.
   Console::WriteLine( "\t-KEY-\t-VALUE-" );
   for ( int i = 0; i < mySL->Count; i++ )
      Console::WriteLine( "\t{0}\t{1}", myKeyList[ i ], myValueList[ i ] );
}

/*
This code produces the following output.

The key   at index 3 is 1.3.
The value at index 3 is fox.
        -KEY-   -VALUE-
        1       The
        1.1     quick
        1.2     brown
        1.3     fox
        1.4     jumps
        1.5     over
        1.6     the
        1.7     lazy
        1.8     dog
*/

using System;
using System.Collections;
public class SamplesSortedList  {

   public static void Main()  {

      // Creates and initializes a new SortedList.
      SortedList mySL = new SortedList();
      mySL.Add( 1.3, "fox" );
      mySL.Add( 1.4, "jumps" );
      mySL.Add( 1.5, "over" );
      mySL.Add( 1.2, "brown" );
      mySL.Add( 1.1, "quick" );
      mySL.Add( 1.0, "The" );
      mySL.Add( 1.6, "the" );
      mySL.Add( 1.8, "dog" );
      mySL.Add( 1.7, "lazy" );

      // Gets the key and the value based on the index.
      int myIndex=3;
      Console.WriteLine( "The key   at index {0} is {1}.", myIndex, mySL.GetKey( myIndex ) );
      Console.WriteLine( "The value at index {0} is {1}.", myIndex, mySL.GetByIndex( myIndex ) );

      // Gets the list of keys and the list of values.
      IList myKeyList = mySL.GetKeyList();
      IList myValueList = mySL.GetValueList();

      // Prints the keys in the first column and the values in the second column.
      Console.WriteLine( "\t-KEY-\t-VALUE-" );
      for ( int i = 0; i < mySL.Count; i++ )
         Console.WriteLine( "\t{0}\t{1}", myKeyList[i], myValueList[i] );
   }
}
/*
This code produces the following output.

The key   at index 3 is 1.3.
The value at index 3 is fox.
    -KEY-    -VALUE-
    1    The
    1.1    quick
    1.2    brown
    1.3    fox
    1.4    jumps
    1.5    over
    1.6    the
    1.7    lazy
    1.8    dog
*/

Imports System.Collections

Public Class SamplesSortedList
        
    Public Shared Sub Main()
        
        ' Creates and initializes a new SortedList.
        Dim mySL As New SortedList()
        mySL.Add(1.3, "fox")
        mySL.Add(1.4, "jumps")
        mySL.Add(1.5, "over")
        mySL.Add(1.2, "brown")
        mySL.Add(1.1, "quick")
        mySL.Add(1.0, "The")
        mySL.Add(1.6, "the")
        mySL.Add(1.8, "dog")
        mySL.Add(1.7, "lazy")
        
        ' Gets the key and the value based on the index.
        Dim myIndex As Integer = 3
        Console.WriteLine("The key   at index {0} is {1}.", myIndex, _
           mySL.GetKey(myIndex))
        Console.WriteLine("The value at index {0} is {1}.", myIndex, _
           mySL.GetByIndex(myIndex))
        
        ' Gets the list of keys and the list of values.
        Dim myKeyList As IList = mySL.GetKeyList()
        Dim myValueList As IList = mySL.GetValueList()
        
        ' Prints the keys in the first column and the values in the second column.
        Console.WriteLine(ControlChars.Tab & "-KEY-" & ControlChars.Tab & _
           "-VALUE-")
        Dim i As Integer
        For i = 0 To mySL.Count - 1
            Console.WriteLine(ControlChars.Tab & "{0}" & ControlChars.Tab & _
               "{1}", myKeyList(i), myValueList(i))
        Next i
    End Sub
End Class

' This code produces the following output.
' 
' The key   at index 3 is 1.3.
' The value at index 3 is fox.
'     -KEY-    -VALUE-
'     1    The
'     1.1    quick
'     1.2    brown
'     1.3    fox
'     1.4    jumps
'     1.5    over
'     1.6    the
'     1.7    lazy
'     1.8    dog

注解

索引序列基于排序序列。 添加元素时，它将按正确的排序顺序插入到 中 SortedList ，索引会相应地调整。 删除元素时，索引也会相应地进行调整。 因此，在对象中添加或移除元素时，特定键/值对的 SortedList 索引可能会更改。

此方法是一个 O(1) 操作。