string 类型（它是 System.String 类的别名）为搜索字符串的内容提供了许多有用的方法。下面的示例使用 IndexOf、LastIndexOf、StartsWith 和 EndsWith 方法。

示例

C# CopyCode image复制代码
class StringSearch
{
    static void Main()
    {
        string str = "A silly sentence used for silly purposes.";
        System.Console.WriteLine("'{0}'",str);

        bool test1 = str.StartsWith("a silly");
        System.Console.WriteLine("starts with 'a silly'? {0}", test1);

        bool test2 = str.StartsWith("a silly", System.StringComparison.OrdinalIgnoreCase);
        System.Console.WriteLine("starts with 'a silly'? {0} (ignoring case)", test2);

        bool test3 = str.EndsWith(".");
        System.Console.WriteLine("ends with '.'? {0}", test3);

        int first = str.IndexOf("silly");
        int last = str.LastIndexOf("silly");
        string str2 = str.Substring(first, last - first);
        System.Console.WriteLine("between two 'silly' words: '{0}'", str2);
    }
}

输出

 
'A silly sentence used for silly purposes.'
starts with 'a silly'? False
starts with 'a silly'? True (ignore case)
ends with '.'? True
between two 'silly' words: 'silly sentence used for '

请参见