SortedList.Contains(Object) 方法

定义

确定 SortedList 对象是否包含特定键。Determines whether a SortedList object contains a specific key.

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

参数

key
Object

要在 SortedList 对象中查找的键。The key to locate in the SortedList object.

返回

如果 true 对象包含带有指定 SortedList 的元素,则为 key;否则为 falsetrue if the SortedList object contains an element with the specified key; otherwise, false.

实现

异常

keynullkey is null.

比较器引发异常。The comparer throws an exception.

示例

下面的代码示例演示如何确定 SortedList 对象是否包含特定元素。The following code example shows how to determine whether a SortedList object contains a specific element.

#using <system.dll>

using namespace System;
using namespace System::Collections;
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();
}

int main()
{
   
   // Creates and initializes a new SortedList.
   SortedList^ mySL = gcnew SortedList;
   mySL->Add( 2, "two" );
   mySL->Add( 4, "four" );
   mySL->Add( 1, "one" );
   mySL->Add( 3, "three" );
   mySL->Add( (int^)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 ) ? (String^)"in the SortedList" : "NOT in the SortedList" );
   myKey = 6;
   Console::WriteLine(  "The key \"{0}\" is {1}.", myKey, mySL->ContainsKey( myKey ) ? (String^)"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 ) ? (String^)"in the SortedList" : "NOT in the SortedList" );
   myValue =  "nine";
   Console::WriteLine(  "The value \"{0}\" is {1}.", myValue, mySL->ContainsValue( myValue ) ? (String^)"in the SortedList" : "NOT in the SortedList" );
}

/* 
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.
*/
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. 

注解

SortedList 对象的元素根据创建 SortedList 时指定的特定 IComparer 实现进行排序,或根据键本身所提供的 IComparable 实现进行排序。The elements of a SortedList object are sorted by the keys either according to a specific IComparer implementation specified when the SortedList is created or according to the IComparable implementation provided by the keys themselves.

Contains 可实现 IDictionary.ContainsContains implements IDictionary.Contains. 它的行为与 ContainsKey完全相同。It behaves exactly as ContainsKey.

此方法使用二进制搜索算法;因此,此方法是 O(log n) 操作,其中 nCount的。This method uses a binary search algorithm; therefore, this method is an O(log n) operation, where n is Count.

从 .NET Framework 2.0 开始,此方法使用集合的对象的 Equals 并在 itemCompareTo 方法来确定项是否存在。Starting with the .NET Framework 2.0, this method uses the collection's objects' Equals and CompareTo methods on item to determine whether item exists. 在 .NET Framework 的早期版本中,此决定是使用集合中对象上的 item 参数的 EqualsCompareTo 方法进行的。In the earlier versions of the .NET Framework, this determination was made by using the Equals and CompareTo methods of the item parameter on the objects in the collection.

适用于

另请参阅