SortedList.IndexOfValue(Object) 方法

定义

返回指定的值在 SortedList 对象中第一个匹配项的从零开始的索引。Returns the zero-based index of the first occurrence of the specified value in a SortedList object.

public:
 virtual int IndexOfValue(System::Object ^ value);
public virtual int IndexOfValue (object value);
abstract member IndexOfValue : obj -> int
override this.IndexOfValue : obj -> int
Public Overridable Function IndexOfValue (value As Object) As Integer

参数

value
Object

要在 SortedList 对象中定位的值。The value to locate in the SortedList object. 该值可以为 nullThe value can be null.

返回

如果在 value 对象中找到 value,则为 SortedList 参数的第一个匹配项的从零开始的索引;否则为 -1。The zero-based index of the first occurrence of the value parameter, if value is found in the SortedList object; otherwise, -1.

示例

下面的代码示例演示如何确定 SortedList 对象中的键或值的索引。The following code example shows how to determine the index of a key or a value in a SortedList object.

#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( 1, "one" );
   mySL->Add( 3, "three" );
   mySL->Add( 2, "two" );
   mySL->Add( 4, "four" );
   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 at index {1}.", myKey, mySL->IndexOfKey( myKey ) );
   
   // Searches for a specific value.
   String^ myValue = "three";
   Console::WriteLine( "The value \"{0}\" is at index {1}.", myValue, mySL->IndexOfValue( myValue ) );
}

/*
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 at index 2.
The value "three" is at index 3.
*/
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, "one" );
      mySL.Add( 3, "three" );
      mySL.Add( 2, "two" );
      mySL.Add( 4, "four" );
      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 at index {1}.", myKey, mySL.IndexOfKey( myKey ) );

      // Searches for a specific value.
      String myValue = "three";
      Console.WriteLine( "The value \"{0}\" is at index {1}.", myValue, mySL.IndexOfValue( myValue ) );
   }

   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 at index 2.
The value "three" is at index 3.
*/ 
Imports System.Collections

Public Class SamplesSortedList    
    
    Public Shared Sub Main()
        
        ' Creates and initializes a new SortedList.
        Dim mySL As New SortedList()
        mySL.Add(1, "one")
        mySL.Add(3, "three")
        mySL.Add(2, "two")
        mySL.Add(4, "four")
        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
        Console.WriteLine("The key ""{0}"" is at index {1}.", myKey, _
           mySL.IndexOfKey(myKey))
        
        ' Searches for a specific value.
        Dim myValue As String = "three"
        Console.WriteLine("The value ""{0}"" is at index {1}.", myValue, _
           mySL.IndexOfValue(myValue))
    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 at index 2.
' The value "three" is at index 3.

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.

使用 Equals 方法将 SortedList 的元素的值与指定的值进行比较。The values of the elements of the SortedList are compared to the specified value using the Equals method.

此方法使用线性搜索;因此,此方法是 O(n) 操作,其中 nCount的。This method uses a linear search; therefore, this method is an O(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