SortedList.ContainsKey(Object) Metod

Definition

Avgör om ett SortedList objekt innehåller en specifik nyckel.

public:
 virtual bool ContainsKey(System::Object ^ key);
public virtual bool ContainsKey(object key);
abstract member ContainsKey : obj -> bool
override this.ContainsKey : obj -> bool
Public Overridable Function ContainsKey (key As Object) As Boolean

Parametrar

key
Object

Nyckeln som ska hittas SortedList i objektet.

Returer

true om objektet SortedList innehåller ett element med angivet key, annars , false.

Undantag

key är null.

Jämförelsen genererar ett undantag.

Exempel

I följande kodexempel visas hur du avgör om ett SortedList objekt innehåller ett specifikt element.

using System;
using System.Collections;

public class SamplesSortedList  {

   public static void Main()  {

      // Creates and initializes a new SortedList.
      SortedList mySL = new SortedList();
      mySL.Add( 2, "two" );
      mySL.Add( 4, "four" );
      mySL.Add( 1, "one" );
      mySL.Add( 3, "three" );
      mySL.Add( 0, "zero" );

      // Displays the values of the SortedList.
      Console.WriteLine( "The SortedList contains the following values:" );
      PrintIndexAndKeysAndValues( mySL );

      // Searches for a specific key.
      int myKey = 2;
      Console.WriteLine( "The key \"{0}\" is {1}.", myKey, mySL.ContainsKey( myKey ) ? "in the SortedList" : "NOT in the SortedList" );
      myKey = 6;
      Console.WriteLine( "The key \"{0}\" is {1}.", myKey, mySL.ContainsKey( myKey ) ? "in the SortedList" : "NOT in the SortedList" );

      // Searches for a specific value.
      string myValue = "three";
      Console.WriteLine( "The value \"{0}\" is {1}.", myValue, mySL.ContainsValue( myValue ) ? "in the SortedList" : "NOT in the SortedList" );
      myValue = "nine";
      Console.WriteLine( "The value \"{0}\" is {1}.", myValue, mySL.ContainsValue( myValue ) ? "in the SortedList" : "NOT in the SortedList" );
   }

   public static void PrintIndexAndKeysAndValues( SortedList myList )  {
      Console.WriteLine( "\t-INDEX-\t-KEY-\t-VALUE-" );
      for ( int i = 0; i < myList.Count; i++ )  {
         Console.WriteLine( "\t[{0}]:\t{1}\t{2}", i, myList.GetKey(i), myList.GetByIndex(i) );
      }
      Console.WriteLine();
   }
}
/*
This code produces the following output.

The SortedList contains the following values:
    -INDEX-    -KEY-    -VALUE-
    [0]:    0    zero
    [1]:    1    one
    [2]:    2    two
    [3]:    3    three
    [4]:    4    four

The key "2" is in the SortedList.
The key "6" is NOT in the SortedList.
The value "three" is in the SortedList.
The value "nine" is NOT in the SortedList.
*/
Imports System.Collections

Public Class SamplesSortedList    
    
    Public Shared Sub Main()
        
        ' Creates and initializes a new SortedList.
        Dim mySL As New SortedList()
        mySL.Add(2, "two")
        mySL.Add(4, "four")
        mySL.Add(1, "one")
        mySL.Add(3, "three")
        mySL.Add(0, "zero")
        
        ' Displays the values of the SortedList.
        Console.WriteLine("The SortedList contains the following values:")
        PrintIndexAndKeysAndValues(mySL)
        
        ' Searches for a specific key.
        Dim myKey As Integer = 2
        Dim msg As String
        If mySL.ContainsKey(myKey) Then
            msg = "in the SortedList"
        Else
            msg = "NOT in the SortedList"
        End If
        Console.WriteLine("The key ""{0}"" is {1}.", myKey, msg)
        myKey = 6
        If mySL.ContainsKey(myKey) Then
            msg = "in the SortedList"
        Else
            msg = "NOT in the SortedList"
        End If
        Console.WriteLine("The key ""{0}"" is {1}.", myKey, msg)        
        ' Searches for a specific value.
        Dim myValue As String = "three"
        If mySL.ContainsValue(myValue) Then
            msg = "in the SortedList"
        Else
            msg = "NOT in the SortedList"
        End If
        Console.WriteLine("The value ""{0}"" is {1}.", myValue, msg)
        myValue = "nine"
        If mySL.ContainsValue(myValue) Then
            msg = "in the SortedList"
        Else
            msg = "NOT in the SortedList"
        End If
        Console.WriteLine("The value ""{0}"" is {1}.", myValue, msg)
    End Sub   
    
    
    Public Shared Sub PrintIndexAndKeysAndValues(myList As SortedList)
        Console.WriteLine(ControlChars.Tab & "-INDEX-" & ControlChars.Tab & _
           "-KEY-" & ControlChars.Tab & "-VALUE-")
        Dim i As Integer
        For i = 0 To myList.Count - 1
            Console.WriteLine(ControlChars.Tab & "[{0}]:" & ControlChars.Tab & _
               "{1}" & ControlChars.Tab & "{2}", i, myList.GetKey(i), _
               myList.GetByIndex(i))
        Next i
        Console.WriteLine()
    End Sub
End Class

' This code produces the following output.
' 
' The SortedList contains the following values:
'     -INDEX-    -KEY-    -VALUE-
'     [0]:    0    zero
'     [1]:    1    one
'     [2]:    2    two
'     [3]:    3    three
'     [4]:    4    four
' 
' The key "2" is in the SortedList.
' The key "6" is NOT in the SortedList.
' The value "three" is in the SortedList.
' The value "nine" is NOT in the SortedList.

Kommentarer

Elementen i ett SortedList objekt sorteras efter nycklarna antingen enligt en specifik IComparer implementering som anges när SortedList det skapas eller enligt implementeringen IComparable som tillhandahålls av själva nycklarna.

Den här metoden fungerar exakt som Contains metoden.

Den här metoden använder en algoritm för binär sökning. Därför är den här metoden en O(log n) åtgärd, där n är Count.

Den här metoden använder samlingens objekt Equals och metoder för item att avgöra om item det CompareTo finns.

Gäller för

Se även