集合与文件操作

今天在云和学院学习了集合和文件操作

ArrayList的添加、移除、清除

            string[] strs = { "阳光路上", "如果爱", "玫瑰花的葬礼", "超级英雄" };
            string str = "love";
            int i = 1;
            double d = 10.21;
            float f = 1.2f;
            ArrayList arraylist = new ArrayList();
            arraylist.Add(str);
            arraylist.Add(i);
            arraylist.Add(d);
            arraylist.Add(f);
            arraylist.AddRange(strs);
            arraylist.Remove(1);
            arraylist.RemoveAt(3);
            arraylist.Clear();
            foreach (var item in arraylist)
            {
                Console.WriteLine(item);
            }
            Console.ReadKey();             

Hashtable

            Hashtable table = new Hashtable();
            table.Add("1", "宋祖英");
            table.Add("2", "凤凰传奇");
            table.Add("3", "何炅");
            foreach (var item in table.Keys)
            {
                Console.WriteLine(item);
            }
            Console.ReadKey();

List:泛型集合

            List<int> list = new List<int>() { 12, 45, 3, 78 };
            foreach (var item in list)
            {
                Console.WriteLine(item);
            }
             Console.ReadKey();

Dictionary

 Dictionary<string, int> dictionary = new Dictionary<string, int>();
            dictionary.Add("李谷一",1);
            dictionary.Add("牛莉",2);
            dictionary.Add("伊能静",3);
            foreach (var item in dictionary.Keys)
            {
                Console.WriteLine(item);
            }
            Console.ReadKey();

文件操作：File

命名空间：using System.IO;

创建文件：

string path = @"d:11.txt";
 File.CreateText(path);
            Console.WriteLine("创建文件");
            Console.ReadKey();

Path

string str = @"E:\\KwDownload\";
            string strs = "song\\S.H.E-美丽新世界.mp3";
            Console.WriteLine(Path.Combine(str,strs));
            string path = @"E:\KwDownload\song\S.H.E-美丽新世界.mp3";
            Console.WriteLine(Path.GetExtension(path));
            Console.WriteLine(Path.GetFileName(path));
            Console.WriteLine(Path.GetFileNameWithoutExtension(path));
            Console.WriteLine(Path.GetFullPath(path));
            Console.WriteLine(Path.GetDirectoryName(path));
            string s = @"d:\11.txt";
            Console.WriteLine(Path.ChangeExtension(s,"doc"));
            Console.ReadKey();

Path.Combine:合并路径

Path.GetExtension：取得扩展名

Path.GetFileName：取得文件名

Path.GetFullPath：取得完整的路径

Path.ChangeExtension：改变扩展名