4、C#进阶：MD5加密、进程、线程、GDI+、XML、委托

 1 PRotected void Page_Load(object sender, EventArgs e) 2 { 3     string s = "123"; 4     Response.Write(getMd5(s)); 5 } 6 public string getMd5(string str) 7 { 8     MD5 md5 = MD5.Create();//MD5抽象类无法实例化 实例化该方法 9     byte[] buffer = Encoding.Default.GetBytes(str); //将字符串转换为字节数组10     byte[] mdbuffer = md5.ComputeHash(buffer); //调用ComputeHash方法把数组传进去11     //将字节数组中每个元素ToString();12     StringBuilder result = new StringBuilder();13     for (int i = 0; i < mdbuffer.Length; i++)14     {15         result.Append(mdbuffer[i].ToString("x2")); //ToString得到十进制字符串 ToString("x")十六进制字符串 ToString("x2")对齐16     }17     return result.ToString();18 }

 1 Directory.CreateDirectory("d:/ccc/cc"); //创建文件夹 2  3 Directory.Delete("d:/ccc",true); //true删除非空文件夹 4  5 Directory.Move(@"d:/ccc", @"d:/cccc"); //剪切操作 源目录没了 必须同一卷轴d盘 6  7 string[] s = Directory.GetFiles(@"D:/项目/Web/Images/shiji"); //获得文件夹目录下所有文件全路径 8  9 string[] s = Directory.GetFiles(@"D:/项目/Web/Images/shiji","*.jpg"); //获得文件夹目录下指定后缀名文件全路径10 11 string[] s = Directory.GetDirectories(@"D:/项目/Web/Images"); //获得文件夹目录下的文件夹的全路径12 13 Directory.Exists(@"D:/项目/Web/Images") //是否存在某文件夹

 1 ///获得当前程序中正在运行的进程 2 Process[] pros = Process.GetProcesses(); 3 foreach (var item in pros) 4 {
　　　　//item.Kill(); //关闭所有进程.
　　　　//item.ProcessName; //进程名 5     Console.Write(item.ToString()); 6 } 7 //通过进程打开一些程序 8 Process.Start("calc"); //打开计算器 9 Process.Start("notepad"); //打开记事本10 //打开指定文件11 ProcessStartInfo pro = new ProcessStartInfo(@"d:/11.txt");12 Process pr = new Process();13 pr.StartInfo = pro;14 pr.Start();

 1 //实例化Thread类，并传入一个指向线程所要运行的方法。（这时线程已经产生，但还没有运行） 2 //调用Thread类的Start方法，标记线程可以被CPU执行了，但具体执行事件由CPU决定。 3 Thread th = new Thread(Test); //创建一个线程去执行这个方法。 4 th.IsBackground = true; //将线程设置为后台线程，前台关闭后 线程结束。 5 th.Start(); //标记准备就绪，可以随意被执行，具体什么时候执行由CPU决定。 6 //在.net下是不允许跨线程访问的。 7 //有时候需要手动释放线程 关闭时 判断线程是否关闭  8 if (th != null) 9 {10     th.Abort(); //结束这个线程 不能再Start()11 }12 Thread.Sleep(3000); //睡眠3秒后执行13 //线程执行带参数方法14 Thread.Start("123")； object类型参数 在start后括号写参数

Graphics g = this.CreateGraphics(); //创建GDI对象Pen pen = new Pen(Brushes.Yellow); //创建画笔Point p1 = new Point(30, 50); //创建两个点Point p2 = new Point(250, 250);g.DrawLine(pen, p1, p2);

 1 /// <summary> 2 /// 字符 3 /// </summary> 4 /// <param name="len">几位</param> 5 /// <returns></returns> 6 public static string validation(int cd) 7 { 8     var ran = new Random(); 9     int num, tem;10     string rtuStr = "";11     for (int i = 0; i < cd; i++)12     {13         num = ran.Next();14         if (i % 2 == 1)15             tem = num % 10 + '0'; //数字16         else17             tem = num % 26 + 'A'; //字母18         rtuStr += Convert.ToChar(tem).ToString();19     }20     //写入cookie21     HttpCookie cookie = new HttpCookie("check");22     cookie.Value = rtuStr.ToLower();23     HttpContext.Current.Response.Cookies.Add(cookie);24     return rtuStr;25 }26 27 /// <summary>28 /// 生成图像29 /// </summary>30 /// <param name="check">字符</param>31 public static byte[] drawImg(string check)32 {33     Bitmap img = new Bitmap(90, 34);34     var ht = Graphics.FromImage(img);35     ht.Clear(Color.White);36     ht.DrawLine(new Pen(Color.SpringGreen), 1, 1, 90, 34);37     Font font = new Font("微软雅黑", 20, FontStyle.Bold);38     var jianbian = new LinearGradientBrush(new Rectangle(0, 0, img.Width, img.Height), Color.Teal, Color.Snow, 2f, true);39     ht.DrawString(check, font, jianbian, 0, 0);40     ht.DrawRectangle(new Pen(Color.Aqua), 0, 0, img.Width - 1, img.Height - 1);41     MemoryStream ms = new MemoryStream();42     img.Save(ms, ImageFormat.Jpeg);43     ht.Dispose();44     img.Dispose();45     return ms.ToArray();46 }

1 public ActionResult ShowValidate()2 {3     var check = Common.Validate.validation(4);4     byte[] buffer = Common.Validate.drawImg(check);5     return File(buffer, "image/jpeg");6 }

<img src="/Login/ShowValidate" id="img" onclick="changeCode()" class="validateImg">if (validateCode.toLowerCase() == getCode()) {    return true;        }        function changeCode() {    $("#img").attr("src", $("#img").attr("src") + "?");}function getCode() {    var cookies = document.cookie.split(";");    for (var i = 0; i < cookies.length; i++) {        var validate = cookies[i].split("=");        if (validate[0].replace(/(^/s*)|(/s*$)/g, "") == "check") {            return validate[1].replace(/(^/s*)|(/s*$)/g,"");        }    }}

 1 //创建XML对象 2 XmlDocument doc = new XmlDocument(); 3 //创建文档描述信息 4 XmlDeclaration dec = doc.CreateXmlDeclaration("1.0", "utf-8", null); 5 doc.AppendChild(dec); 6  7 //创建根节点 8 XmlElement books = doc.CreateElement("Books"); 9 doc.AppendChild(books);10 11 //创建子节点12 XmlElement book1 = doc.CreateElement("Book");13 books.AppendChild(book1); //将子节点添加到books14 15 //给book1子节点追加子节点16 XmlElement name1 = doc.CreateElement("Name");17 name1.InnerText = "c#"; //赋值 文本值18 book1.AppendChild(name1);19 20 XmlElement price1 = doc.CreateElement("Price");21 price1.InnerXml = "<b>10.0</b>"; //赋值 html标签22 book1.AppendChild(price1);23 24 XmlElement items = doc.CreateElement("Items");25 //给节点增加属性26 items.SetAttribute("Name", "c#");27 items.SetAttribute("Price", "10.0");28 book1.AppendChild(items);29 30 doc.Save("Books.xml"); //保存31 32 //创建后33 <?xml version="1.0" encoding="utf-8"?>34 <Books>35   <Book>36     <Name>c#</Name>37     <Price>38       <b>10.0</b>39     </Price>40     <Items Name="c#" Price="10.0" />41   </Book>42 </Books>

1 XmlDocument doc = new XmlDocument();2 if (File.Exists("Books.xml"))3 {4     doc.Load("Books.xml"); //加载 xml5     XmlElement books = doc.DocumentElement; //得到根节点6     //再建立元素进行追加7 }

 1 XmlDocument doc = new XmlDocument(); 2 doc.Load("Books.xml"); 3  4 XmlElement books = doc.DocumentElement; 5 XmlNodeList xnl = books.ChildNodes; //得到所有节点 6  7 foreach (XmlNode v in xnl) //遍历得到所有节点值 8 { 9     Console.WriteLine(v.InnerText);10 }11 12 XmlNodeList xnl1 = doc.SelectNodes("Books/Book/Items"); //查找节点列表13 foreach (XmlNode node in xnl1)14 {15     Console.WriteLine(node.Attributes["Name"].Value); //得到name属性的值16     Console.WriteLine(node.Attributes["Price"].Value); //得到price属性的值17 }

1 XmlDocument doc = new XmlDocument();2 doc.Load("Books.xml");3 4 XmlNode xnl = doc.SelectSingleNode("Books/Book"); //查找单一节点5 xnl.RemoveAll(); //删除全部6 doc.Save("Books.xml");7 Console.ReadKey();

 1 //兼容传统方法创建 2 XDocument xDoc = new XDocument(); 3 //xDoc.Declaration = new XDeclaration() 默认UTF-8 第一行不需要单独建 4 XElement xRoot = new XElement("root", "值"); //定义元素 5  6 XElement xRoot1 = new XElement("root1");  //定义元素２ 7 xRoot1.Value = "值1"; 8  9 XAttribute xattr = new XAttribute("Id", "1"); //定义属性10 11 xDoc.Add(xRoot); //统一使用add添加12 xRoot.Add(xattr);13 14 xDoc.Save(@"d:/linqtoxml.xml");15 16 //真正的linq语法17 //F#  函数式编程语言18 new XDocument(19     new XElement("root",20         new XAttribute("id", "001"),21         "值")22     ).Save(@"d:/2.xml");23 //链式编程，流水线生产 f1().f2().f3()...24 25 //查找xml26 XDocument xdoc = new XDocument(new XElement("root"));//根节点27 xdoc.Root.Add(new XElement("person",28     new XAttribute("id", "1"),29     new XAttribute("name", "zhangsan"),30     new XAttribute("sex", "1")31     )); //添加子节点32 xdoc.Root.Add(new XElement("person",33    new XAttribute("id", "2"),34    new XAttribute("name", "lisi"),35    new XAttribute("sex", "2")36    ));37 xdoc.Save(@"d:/2.xml");38 39 <?xml version="1.0" encoding="utf-8"?>40 <root>41   <person id="1" name="zhangsan" sex="1" />42   <person id="2" name="lisi" sex="2" />43 </root>44 45 //开始查找、修改、删除46 47 XDocument xdoc = XDocument.Load(@"d:/2.xml"); //加载xml48 foreach (XElement xlt in xdoc.Root.Elements()) //Root根节点 Elements 元素集合49 {50     if (xlt.Name.LocalName == "person") //Name节点名 LocalName不带命名空间的节点名51     {52         if (xlt.Attribute("id").Value == "1") //判断属性值为1时53         {54             Response.Write(xlt.Attribute("name").Value); //输出name55             xlt.Attribute("name").Value = "newname"; //修改name56             xlt.Remove(); //删除此节点57             xdoc.Save(@"d:2.xml");58         }59     }60 }61 62 //Linq查询语法63 //Descendants()所有子节点 可加某节点下所有节点64 var query = from s in xdoc.Descendants() //从集合里找 65             where s.Name.LocalName == "person"66             select s;67 foreach (XElement xlt in query)68 {69     Response.Write(xlt.Value);70 }71 72 //Linq方法语法(lambda表达式)73 foreach (XElement xlt in xdoc.Descendants().Where(s =>74 {75     if (s.Name.LocalName == "name")76     {77         return true;78     }79     return false;80 }))81 {82     Response.Write(xlt.Value);83 }

  1 /// <summary>  2 /// 委托语法  3 /// </summary>  4 class Program  5 {  6     public delegate void delSayhi(string name); //定义委托  7     static void Main(string[] args)  8     {  9         delSayhi del = new delSayhi(sayHiChinese); //实例化委托调用具体方法 10         del("san"); //执行 11  12         delSayhi del1 = sayHiChinese; //直接赋值方式 13         del1("si"); 14  15         //匿名函数 16         delSayhi del2 = delegate(string name) { Console.WriteLine(name + "，思密达"); }; 17         del2("韩国"); 18  19         //lambda表达式  ()没参数也要写 => { //方法体 } 没参数可以e=> Console.WriteLine(""); 如果只有一句话不用{} 返回的return可以省略 20         delSayhi del3 = (string name) => { Console.WriteLine(name + "，萨瓦迪卡"); }; 21         del2("泰国"); 22  23         sayHi("david", sayHiEnglish); //调用自定义方法 参数要调用的方法 24         Console.ReadKey(); 25     } 26  27     public static void sayHi(string name, delSayhi del) //定义方法 类型委托 28     { 29         del(name); 30     } 31  32     public static void sayHiChinese(string name) 33     { 34         Console.WriteLine("你好， 我叫" + name); 35     } 36     public static void sayHiEnglish(string name) 37     { 38         Console.WriteLine("hello, my name is {0}, nice to meet you!", name); 39     } 40 } 41  42  43  44 /// <summary> 45 /// 求任意数组最大值 46 /// </summary> 47 class Program 48 { 49     public delegate int delCompre(object o1, object o2); //定义比较委托 50     static void Main(string[] args) 51     { 52         //比较int 53         object[] objs = new object[] { 1, 2, 3, 4, 5, 32, 1, 243, }; 54         var max = getMax(objs, getIntMax); //传入比较int方法 55         Console.WriteLine(max); 56  57         var max2 = getMax(objs, delegate(object o1, object o2) 58         { 59             return int.Parse(o1.ToString()) - int.Parse(o2.ToString()); 60         }); //匿名函数 与比较int一样 61         Console.WriteLine(max2); 62  63         //比较string 64         object[] strs = new object[] { "abc", "efd", "asdf", "sd", "asdff" }; 65         var maxstrs = getMax(strs, delegate(object o1, object o2) 66         { 67             return o1.ToString().Length - o2.ToString().Length; 68         }); //匿名函数 69         Console.WriteLine(maxstrs); 70  71         var maxstrs2 = getMax(strs, (object o1, object o2) => 72         { 73             return o1.ToString().Length - o2.ToString().Length; 74         }); //lambda 表达式 75         Console.WriteLine(maxstrs2); 76  77         Console.ReadKey(); 78     } 79  80     public static int getIntMax(object o1, object o2) //比较int方法 81     { 82         int n1 = int.Parse(o1.ToString()); 83         int n2 = int.Parse(o2.ToString()); 84         return n1 - n2; 85     } 86     /// <summary> 87     /// 取一个任意数组的最大值 88     /// </summary> 89     /// <param name="objs">数组</param> 90     /// <param name="del">委托</param> 91     /// <returns></returns> 92     public static object getMax(object[] objs, delCompre del) 93     { 94         object max = objs[0]; 95         for (int i = 0; i < objs.Length; i++) 96         { 97             //if (max < objs[i]) object 无法确定是什么类型 所以不能用< 98             if (del(max, objs[i]) < 0) //如果委托值小于0 成立 传入如何比较即可 99             {100                 max = objs[i];101             }102         }103         return max;104     }105 }106 107 108 /// <summary>109 /// 泛型<T>委托110 /// </summary>111 class Program112 {113     public delegate int delCompre<T>(T t1, T t2); //定义泛型委托114     static void Main(string[] args)115     {116         //int117         int[] nums = { 1, 2, 3, 4, 5 };118         int max = getMax<int>(nums, (int t1, int t2) => { return t1 - t2; });119         Console.WriteLine(max);120 121         //string122         string[] strs = { "asd", "sdf", "zxcvv", "123", "qwe" };123         string maxStr = getMax(strs, (string s1, string s2) => { return s1.Length - s2.Length; });124         Console.WriteLine(maxStr);125 126         Console.ReadKey();127     }128 129     public static T getMax<T>(T[] objs, delCompre<T> del)130     {131         T max = objs[0];132         for (int i = 0; i < objs.Length; i++)133         {134             if (del(max, objs[i]) < 0)135             {136                 max = objs[i];137             }138         }139         return max;140     }141 }

1 public delegate void my1();2 3 my1 my = Fun1();4 my+= Fun2(); //+=实现多播委托5 6 public static void Fun1(){7 }8 public static void Fun2(){9 }