List<T>.IndexOf 方法

定义

重载

示例

下面的示例演示方法的所有三个重载 IndexOf 。The following example demonstrates all three overloads of the IndexOf method. 将 List<T> 创建一个字符串，其中一个条目出现两次，位于索引位置0和索引位置5。A List<T> of strings is created, with one entry that appears twice, at index location 0 and index location 5. IndexOf(T)方法重载从开始处搜索列表，并查找字符串的第一个匹配项。The IndexOf(T) method overload searches the list from the beginning, and finds the first occurrence of the string. IndexOf(T, Int32)方法重载用于搜索索引位置3开头的列表并继续到列表末尾，并查找字符串的第二个匹配项。The IndexOf(T, Int32) method overload is used to search the list beginning with index location 3 and continuing to the end of the list, and finds the second occurrence of the string. 最后， IndexOf(T, Int32, Int32) 使用方法重载搜索两个条目的范围（从第二个索引位置开始）; 它返回-1，因为该范围中没有搜索字符串的实例。Finally, the IndexOf(T, Int32, Int32) method overload is used to search a range of two entries, beginning at index location two; it returns -1 because there are no instances of the search string in that range.

using namespace System;
using namespace System::Collections::Generic;

void main()
{
    List<String^>^ dinosaurs = gcnew List<String^>();

    dinosaurs->Add("Tyrannosaurus");
    dinosaurs->Add("Amargasaurus");
    dinosaurs->Add("Mamenchisaurus");
    dinosaurs->Add("Brachiosaurus");
    dinosaurs->Add("Deinonychus");
    dinosaurs->Add("Tyrannosaurus");
    dinosaurs->Add("Compsognathus");

    Console::WriteLine();
    for each(String^ dinosaur in dinosaurs )
    {
        Console::WriteLine(dinosaur);
    }

    Console::WriteLine("\nIndexOf(\"Tyrannosaurus\"): {0}", 
        dinosaurs->IndexOf("Tyrannosaurus"));

    Console::WriteLine("\nIndexOf(\"Tyrannosaurus\", 3): {0}", 
        dinosaurs->IndexOf("Tyrannosaurus", 3));

    Console::WriteLine("\nIndexOf(\"Tyrannosaurus\", 2, 2): {0}", 
        dinosaurs->IndexOf("Tyrannosaurus", 2, 2));
}

/* This code example produces the following output:

Tyrannosaurus
Amargasaurus
Mamenchisaurus
Brachiosaurus
Deinonychus
Tyrannosaurus
Compsognathus

IndexOf("Tyrannosaurus"): 0

IndexOf("Tyrannosaurus", 3): 5

IndexOf("Tyrannosaurus", 2, 2): -1
 */

using System;
using System.Collections.Generic;

public class Example
{
    public static void Main()
    {
        List<string> dinosaurs = new List<string>();

        dinosaurs.Add("Tyrannosaurus");
        dinosaurs.Add("Amargasaurus");
        dinosaurs.Add("Mamenchisaurus");
        dinosaurs.Add("Brachiosaurus");
        dinosaurs.Add("Deinonychus");
        dinosaurs.Add("Tyrannosaurus");
        dinosaurs.Add("Compsognathus");

        Console.WriteLine();
        foreach(string dinosaur in dinosaurs)
        {
            Console.WriteLine(dinosaur);
        }

        Console.WriteLine("\nIndexOf(\"Tyrannosaurus\"): {0}",
            dinosaurs.IndexOf("Tyrannosaurus"));

        Console.WriteLine("\nIndexOf(\"Tyrannosaurus\", 3): {0}",
            dinosaurs.IndexOf("Tyrannosaurus", 3));

        Console.WriteLine("\nIndexOf(\"Tyrannosaurus\", 2, 2): {0}",
            dinosaurs.IndexOf("Tyrannosaurus", 2, 2));
    }
}

/* This code example produces the following output:

Tyrannosaurus
Amargasaurus
Mamenchisaurus
Brachiosaurus
Deinonychus
Tyrannosaurus
Compsognathus

IndexOf("Tyrannosaurus"): 0

IndexOf("Tyrannosaurus", 3): 5

IndexOf("Tyrannosaurus", 2, 2): -1
 */

Imports System.Collections.Generic

Public Class Example

    Public Shared Sub Main()

        Dim dinosaurs As New List(Of String)

        dinosaurs.Add("Tyrannosaurus")
        dinosaurs.Add("Amargasaurus")
        dinosaurs.Add("Mamenchisaurus")
        dinosaurs.Add("Brachiosaurus")
        dinosaurs.Add("Deinonychus")
        dinosaurs.Add("Tyrannosaurus")
        dinosaurs.Add("Compsognathus")

        Console.WriteLine()
        For Each dinosaur As String In dinosaurs
            Console.WriteLine(dinosaur)
        Next

        Console.WriteLine(vbLf & _
            "IndexOf(""Tyrannosaurus""): {0}", _
            dinosaurs.IndexOf("Tyrannosaurus"))

        Console.WriteLine(vbLf & _
            "IndexOf(""Tyrannosaurus"", 3): {0}", _
            dinosaurs.IndexOf("Tyrannosaurus", 3))

        Console.WriteLine(vbLf & _
            "IndexOf(""Tyrannosaurus"", 2, 2): {0}", _
            dinosaurs.IndexOf("Tyrannosaurus", 2, 2))

    End Sub
End Class

' This code example produces the following output:
'
'Tyrannosaurus
'Amargasaurus
'Mamenchisaurus
'Brachiosaurus
'Deinonychus
'Tyrannosaurus
'Compsognathus
'
'IndexOf("Tyrannosaurus"): 0
'
'IndexOf("Tyrannosaurus", 3): 5
'
'IndexOf("Tyrannosaurus", 2, 2): -1

public:
 int IndexOf(T item, int index);

public int IndexOf (T item, int index);

member this.IndexOf : 'T * int -> int

Public Function IndexOf (item As T, index As Integer) As Integer

public:
 int IndexOf(T item, int index, int count);

public int IndexOf (T item, int index, int count);

member this.IndexOf : 'T * int * int -> int

Public Function IndexOf (item As T, index As Integer, count As Integer) As Integer

public:
 virtual int IndexOf(T item);

public int IndexOf (T item);

abstract member IndexOf : 'T -> int
override this.IndexOf : 'T -> int

Public Function IndexOf (item As T) As Integer