SortedList.GetKey(Int32) 方法

定义

获取 SortedList 对象的指定索引处的键。Gets the key at the specified index of a SortedList object.

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。The zero-based index of the key to get.

返回

SortedList 对象的指定索引处的键。The key at the specified index of the SortedList object.

异常

index 不在 SortedList 对象的有效索引范围内。index is outside the range of valid indexes for the SortedList object.

示例

下面的代码示例演示如何获取 SortedList 对象中的一个或全部键或值。The following code example shows how to get one or all the keys or values in a SortedList object.

#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

索引顺序基于排序顺序。The index sequence is based on the sort sequence. 添加元素时,会按正确的顺序将其插入 SortedList 中,并相应地调整索引。When an element is added, it is inserted into SortedList in the correct sort order, and the indexing adjusts accordingly. 删除元素时,索引编制还会相应地进行调整。When an element is removed, the indexing also adjusts accordingly. 因此,在 SortedList 对象中添加或删除元素时,特定键/值对的索引可能会更改。Therefore, the index of a specific key/value pair might change as elements are added or removed from the SortedList object.

此方法是一个 O(1) 操作。This method is an O(1) operation.

适用于