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String.LastIndexOfAny 方法 (Char[], Int32, Int32)

 

报告在 Unicode 数组中指定的一个或多个字符在此实例中的最后一个匹配项的从零开始的索引的位置。 搜索在指定字符位置的数目的字符串开始时,开始指定字符和其后面的位置。

命名空间:   System
程序集:  mscorlib(位于 mscorlib.dll)

public int LastIndexOfAny(
	char[] anyOf,
	int startIndex,
	int count
)

参数

anyOf
Type: System.Char[]

Unicode 字符数组,包含一个或多个要查找的字符。

startIndex
Type: System.Int32

搜索起始位置。startIndex 此实例的开头开始搜索。

count
Type: System.Int32

要检查的字符位置数。

返回值

Type: System.Int32

最后一次在此实例中找到 anyOf 中的任意字符的索引位置;如果未找到 anyOf 中的字符或者当前实例等于String.Empty,则为 -1。

Exception Condition
ArgumentNullException

anyOfnull

ArgumentOutOfRangeException

当前实例不等于 String.Empty,并且 countstartIndex 为负数。

- 或 -

当前实例不等于 String.Empty,并且 startIndex 减去 count 再加 1 小于零。

Index numbering starts from zero.

This method begins searching at the startIndex character position of this instance and proceeds backward toward the beginning until either a character in anyOf is found or count character positions have been examined. The search is case-sensitive.

This method performs an ordinal (culture-insensitive) search, where a character is considered equivalent to another character only if their Unicode scalar values are the same. To perform a culture-sensitive search, use the M:System.Globalization.CompareInfo.LastIndexOf(System.String,System.Char) method, where a Unicode scalar value representing a precomposed character, such as the ligature "Æ" (U+00C6), might be considered equivalent to any occurrence of the character's components in the correct sequence, such as "AE" (U+0041, U+0045), depending on the culture.

The following example finds the index of the last occurrence of any character in the string "aid" within a substring of another string.

// Sample for String.LastIndexOfAny(Char[], Int32, Int32)
using System;

class Sample {
    public static void Main() {

    string br1 = "0----+----1----+----2----+----3----+----4----+----5----+----6----+-";
    string br2 = "0123456789012345678901234567890123456789012345678901234567890123456";
    string str = "Now is the time for all good men to come to the aid of their party.";
    int start;
    int at;
    int count;
    string target = "aid";
    char[] anyOf = target.ToCharArray();

    start = ((str.Length-1)*2)/3;
    count = (str.Length-1)/3;
    Console.WriteLine("The last character occurrence from position {0} for {1} characters.", start, count);
    Console.WriteLine("{1}{0}{2}{0}{3}{0}", Environment.NewLine, br1, br2, str);
    Console.Write("A character in '{0}' occurs at position: ", target);

    at = str.LastIndexOfAny(anyOf, start, count);
    if (at > -1) 
        Console.Write(at);
    else
        Console.Write("(not found)");
    Console.Write("{0}{0}{0}", Environment.NewLine);
    }
}
/*
This example produces the following results:
The last character occurrence from position 44 for 22 characters.
0----+----1----+----2----+----3----+----4----+----5----+----6----+-
0123456789012345678901234567890123456789012345678901234567890123456
Now is the time for all good men to come to the aid of their party.

A character in 'aid' occurs at position: 27
*/

通用 Windows 平台
自 8 起可用
.NET Framework
自 1.1 起可用
可移植类库
可移植 .NET 平台 中受支持
Silverlight
自 2.0 起可用
Windows Phone Silverlight
自 7.0 起可用
Windows Phone
自 8.1 起可用
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