using System;using System.IO;class Test {	    public static void Main()     {        string path1 = @"c:\temp\MyTest.txt";        string path2 = @"c:\temp\MyTest";        string path3 = @"temp";        if (Path.HasExtension(path1))         {            Console.WriteLine("{0} has an extension.", path1);        }        if (!Path.HasExtension(path2))         {            Console.WriteLine("{0} has no extension.", path2);        }        if (!Path.IsPathRooted(path3))         {            Console.WriteLine("The string {0} contains no root information.", path3);        }        Console.WriteLine("The full path of {0} is {1}.", path3, Path.GetFullPath(path3));        Console.WriteLine("{0} is the location for temporary files.", Path.GetTempPath());        Console.WriteLine("{0} is a file available for use.", Path.GetTempFileName());        /* This code produces output similar to the following:         * c:\temp\MyTest.txt has an extension.         * c:\temp\MyTest has no extension.         * The string temp contains no root information.         * The full path of temp is D:\Documents and Settings\cliffc\My Documents\Visual Studio 2005\Projects\ConsoleApplication2\ConsoleApplication2\bin\Debug\temp.         * D:\Documents and Settings\cliffc\Local Settings\Temp\8\ is the location for temporary files.         * D:\Documents and Settings\cliffc\Local Settings\Temp\8\tmp3D.tmp is a file available for use.         */    }}

using System;using System.IO;class Test {	    public static void Main()     {        //通过Path对象获取缓存路径        string path = Path.GetTempFileName();        FileInfo fi1 = new FileInfo(path);        //创建文件，并且通过返回的"文件流写入对象"写入数据        using (StreamWriter sw = fi1.CreateText())         {            sw.WriteLine("Hello");            sw.WriteLine("And");            sw.WriteLine("Welcome");        }	        //打开文件，并且通过返回的"文件流读取对象"读取数据        using (StreamReader sr = fi1.OpenText())         {            string s = "";            while ((s = sr.ReadLine()) != null)             {                Console.WriteLine(s);            }        }        try         {            string path2 = Path.GetTempFileName();            FileInfo fi2 = new FileInfo(path2);            //删除文件            fi2.Delete();            //将f1文件拷贝到f2文件            fi1.CopyTo(path2);            Console.WriteLine("{0} was copied to {1}.", path, path2);            //删除文件            fi2.Delete();            Console.WriteLine("{0} was successfully deleted.", path2);        }         catch (Exception e)         {            Console.WriteLine("The process failed: {0}", e.ToString());        }    }}