.NET开发中你可能会用到的常用方法总结 - 冰云

 1 /// <summary>
 2     /// 将文件转换成字符串,常用于读取网站模板
 3     /// </summary>
 4     /// <param name="path"></param>
 5     /// <param name="isSpace"></param>
 6     /// <returns></returns>
 7      public static string GetTempleContent(string path)
 8     {
 9         string result = string.Empty;
10         string sFileName = HttpContext.Current.Server.MapPath(path);
11         if (File.Exists(sFileName))
12         {
13             try
14             {
15                 using (StreamReader sr = new StreamReader(sFileName))
16                 {
17                     result = sr.ReadToEnd();
18                 }
19             }
20             catch
21             {
22                 result = "读取模板文件(" + path + ")出错";
23             }
24         }
25         else
26         {
27             result = "找不到模板文件：" + path;
28         }
29         return result;
30     }

Code
/// <summary>
 /// 读取,添加，修改xml文件
 /// </summary>
 /// <param name="Xmlpath">Xml路径</param>
 /// <param name="Node">新的子节点名称</param>
 /// <param name="Value">新节点对应的值</param>
 /// <param name="flag">1：读取，否则为修改或者添加</param>
 /// <returns>1：修改添加成功，为空字符串表示修改添加成功，否则是读取成功</returns>
 public static string getXML(string Xmlpath, string Node, string Value, int flag)
 {
 try
 {
 string filepath = HttpContext.Current.Server.MapPath(Xmlpath);
 XmlDocument xmlDoc = new XmlDocument();
 if (!File.Exists(filepath))
 {
 XmlDeclaration xn = xmlDoc.CreateXmlDeclaration("1.0", "utf-8", null);
 XmlElement root = xmlDoc.CreateElement("rss");
 XmlElement root1 = xmlDoc.CreateElement("item");

 root.AppendChild(root1);
 xmlDoc.AppendChild(xn);
 xmlDoc.AppendChild(root);
 xmlDoc.Save(filepath);//本地路径名字
 }
 xmlDoc.Load(filepath);//你的xml文件
 string ReStr = string.Empty;
 XmlElement xmlObj = xmlDoc.DocumentElement;

 XmlNodeList xmlList = xmlDoc.SelectSingleNode(xmlObj.Name.ToString()).ChildNodes;

 foreach (XmlNode xmlNo in xmlList)
 {
 if (xmlNo.NodeType != XmlNodeType.Comment)//判断是不是注释类型
 {
 XmlElement xe = (XmlElement)xmlNo;
 {
 if (xe.Name == xmlObj.FirstChild.Name)
 {
 XmlNodeList xmlNList = xmlObj.FirstChild.ChildNodes;

 foreach (XmlNode xmld in xmlNList)
 {
 XmlElement xe1 = (XmlElement)xmld;
 {
 if (xe1.Name == Node)
 {
 if (flag == 1)//读取值
 {
 if (xmld.InnerText != null && xmld.InnerText != "")
 {
 ReStr = xmld.InnerText;
 }
 }
 else//修改值
 {
 xmld.InnerText = Value;//给节点赋值
 xmlDoc.Save(filepath);
 ReStr = Value.Trim();
 }
 }
 }
 }
 if (ReStr == string.Empty)// 添加节点
 {
 XmlNode newNode;
 newNode = xmlDoc.CreateNode("element", Node, Value);//创建节点
 newNode.InnerText = Value;//给节点赋值
 xe.AppendChild(newNode);//把节点添加到doc
 xmlDoc.Save(filepath);
 ReStr = Value.Trim();
 }
 }
 }
 }
 }
 return ReStr;
 }
 catch
 {
 return string.Empty;
 }
 }

Code
/// <summary>
 /// 取得文件扩展名
 /// </summary>
 /// <param name="filename">文件名</param>
 /// <returns>扩展名</returns>
 public static string GetFileEXT(string filename)
 {
 if (string.IsNullOrEmpty(filename))
 {
 return "";
 }
 if (filename.IndexOf(@".") == -1)
 {
 return "";
 }
 int pos = -1;
 if (!(filename.IndexOf(@"\") == -1))
 {
 pos = filename.LastIndexOf(@"\");
 }
 string[] s = filename.Substring(pos + 1).Split('.');
 return s[1];
 }

Code
/// <summary>
 /// 替换文本中的空格和换行
 /// </summary>
 public static string ReplaceSpace(string str)
 {
 string s = str;
 s = s.Replace(" ", " ");
 s = s.Replace("\n", " ");
 return s;
 }

Code
 protected void Page_Load(object sender, EventArgs e)
 {
 string checkCode = CreateRandomCode(4);
 Session["CheckCode"] = checkCode;
 CreateImage(checkCode);
 }
 private string CreateRandomCode(int codeCount)
 {

 // 函数功能:产生数字和字符混合的随机字符串
 string allChar = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
 char[] allCharArray = allChar.ToCharArray();
 string randomCode = "";
 Random rand = new Random();
 for (int i = 0; i < codeCount; i++)
 {
 int r=rand.Next(61);
 randomCode+=allCharArray.GetValue(r);
 }
 return randomCode;

 }


 private void CreateImage(string checkCode)
 {

 // 生成图象验证码函数
 int iwidth = (int)(checkCode.Length * 11.5);
 System.Drawing.Bitmap image = new System.Drawing.Bitmap(iwidth, 20);
 Graphics g = Graphics.FromImage(image);
 Font f = new System.Drawing.Font("Arial", 10, System.Drawing.FontStyle.Bold);
 Brush b = new System.Drawing.SolidBrush(Color.Azure);//字母白色
 //g.FillRectangle(new System.Drawing.SolidBrush(Color.Blue),0,0,image.Width, image.Height);
 g.Clear(Color.Brown);//背景灰色
 g.DrawString(checkCode, f, b, 3, 3);

 Pen blackPen = new Pen(Color.Black, 0);
 Random rand = new Random();
 System.IO.MemoryStream ms = new System.IO.MemoryStream();
 image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
 Response.ClearContent();
 Response.ContentType = "image/Jpeg";
 Response.BinaryWrite(ms.ToArray());
 g.Dispose();
 image.Dispose();
 }

Code
FileStream fs;
//创建文件
fs = File.Create(Server.MapPath("a.txt"));
fs.Close();
fs = File.Create(Server.MapPath("b.txt"));
fs.Close();
fs = File.Create(Server.MapPath("c.txt"));
fs.Close();
//复制文件
File.Copy(Server.MapPath("a.txt"), Server.MapPath("a\\a.txt"));
//移动文件
File.Move(Server.MapPath("b.txt"), Server.MapPath("a\\b.txt"));
File.Move(Server.MapPath("c.txt"), Server.MapPath("a\\c.txt"));
//删除文件
File.Delete(Server.MapPath("a.txt"));

Code
/// <summary>
 /// 去掉结尾，
 /// </summary>
 /// <param name="input"></param>
 /// <returns></returns>
 public static string LostDot(string input)
 {
 if (string.IsNullOrEmpty(input))
 {
 return string.Empty;
 }
 else
 {
 if (input.IndexOf(",") > -1)
 {
 int intLast = input.LastIndexOf(",");
 if ((intLast + 1) == input.Length)
 {
 return input.Remove(intLast);
 }
 else
 {
 return input;
 }
 }
 else
 {
 return input;
 }
 }
 }

Code
/// <summary>
 /// 生成随机数
 /// </summary>
 /// <param name="minValue">最小值</param>
 /// <param name="maxValue">最大值</param>
 /// <returns></returns>
 private int getRandom(int minValue, int maxValue)
 {
 Random ri = new Random(unchecked((int)DateTime.Now.Ticks));
 int k = ri.Next(minValue, maxValue);
 return k;
 }

//想定一个三位的随机数：string ThreeRandom=this.getRandom(100,999).Tostring();
//类似的，四位随机数：string FourRandom=this.getRandom(1000,9999).Tostring();

Code
public class Upload
 {
 private System.Web.HttpPostedFile postedFile = null;
 private string savePath = "";
 private string extension = "";
 private int fileLength = 0;
 private string filename = "";
 /// <summary>
 /// 上传组件
 /// </summary>
 public System.Web.HttpPostedFile PostedFile
 {
 get
 {
 return postedFile;
 }
 set
 {
 postedFile = value;
 }
 }
 /// <summary>
 /// 保存路径
 /// </summary>
 public string SavePath
 {
 get
 {
 if (savePath != "") return savePath;
 return "c:\\";
 }
 set
 {
 savePath = value;
 }
 }
 /// <summary>
 /// 文件大小
 /// </summary>
 public int FileLength
 {
 get
 {
 if (fileLength != 0) return fileLength;
 return 1024;
 }
 set
 {
 fileLength = value * 1024;
 }
 }
 /// <summary>
 /// 文件护展名
 /// </summary>
 public string Extension
 {
 get
 {
 if (extension != "")
 return extension;
 return "txt";
 }
 set
 {
 extension = value;
 }
 }
 /// <summary>
 /// 文件名
 /// </summary>
 public string FileName
 {
 get
 {
 return filename;
 }
 set
 {
 filename = value;
 }
 }
 public string PathToName(string path)
 {
 int pos = path.LastIndexOf(@"\");
 return path.Substring(pos + 1);
 }
 /// <summary>
 /// 上传文件
 /// </summary>
 /// <returns></returns>
 public string UploadStart()
 {
 bool tf = false;
 string returnvalue = "";
 if (PostedFile != null)
 {
 try
 {
 string fileName = PathToName(PostedFile.FileName);
 if (filename != "")
 {
 fileName = filename;
 }
 string _fileName = "";

 string[] Exten = Extension.Split(',');
 if (Exten.Length == 0)
 {
 returnvalue = "你未设置上传文件类型,系统不允许进行下一步操作!";
 }
 else
 {
 for (int i = 0; i < Exten.Length; i++)
 {
 if (fileName.ToLower().EndsWith(Exten[i].ToLower()))
 {
 if (PostedFile.ContentLength > FileLength)
 {
 returnvalue = "上传文件限制大小:" + FileLength / 1024 + "kb!";
 }
 string IsFileex = SavePath + @"\" + fileName;
 if (!Directory.Exists(SavePath)) { Directory.CreateDirectory(SavePath); }
 PostedFile.SaveAs(IsFileex);
 _fileName = fileName;
 tf = true;
 returnvalue = IsFileex ;
 }
 }
 if (tf == false)
 returnvalue = "只允许上传" + Extension + " 文件!";
 }
 }
 catch (System.Exception exc)
 {
 returnvalue = exc.Message;
 }
 }
 else
 {
 returnvalue = "上文件失败!";
 }
 return returnvalue;
 }
 }

Code
/// <summary>
 /// 判断输入是否为日期类型
 /// </summary>
 /// <param name="s">待检查数据</param>
 /// <returns></returns>
 public static bool IsDate(string s)
 {
 if (s == null)
 {
 return false;
 }
 else
 {
 try
 {
 DateTime d = DateTime.Parse(s);
 return true;
 }
 catch
 {
 return false;
 }
 }
 }

Code
/// <summary>
 /// MD5加密字符串处理
 /// </summary>
 /// <param name="Half">加密是16位还是32位；如果为true为16位</param>
 public static string MD5(string Input, bool Half)
 {
 string output = System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(Input, "MD5").ToLower();
 if (Half) output = output.Substring(8, 16);
 return output;
 }

 public static string MD5(string Input)
 {
 return MD5(Input, true);
 }

Code
/// <summary>
 /// 过滤字符
 /// </summary>
 public static string Filter(string sInput)
 {
 if (sInput == null || sInput.Trim() == string.Empty)
 return null;
 string sInput1 = sInput.ToLower();
 string output = sInput;
 string pattern = @"*|and|exec|insert|select|delete|update|count|master|truncate|declare|char(|mid(|chr(|'";
 if (Regex.Match(sInput1, Regex.Escape(pattern), RegexOptions.Compiled | RegexOptions.IgnoreCase).Success)
 {
 throw new Exception("字符串中含有非法字符!");
 }
 else
 {
 output = output.Replace("'", "''");
 }
 return output;
 }

Code
 using System.Security.Cryptography;
using System.Text;

 /// <summary>
 /// DES加密
 /// </summary>
 /// <param name="input">待加密的字符串</param>
 /// <param name="key">加密密钥</param>
 /// <returns></returns>
 public static string Encrypt(string EncryptString, byte[] Key, byte[] IV)
 {
 //byte[] rgbKey = Encoding.UTF8.GetBytes(key.Substring(0, 8));
 byte[] inputByteArray = Encoding.UTF8.GetBytes(EncryptString);
 DESCryptoServiceProvider des = new DESCryptoServiceProvider();
 MemoryStream mStream = new MemoryStream();
 CryptoStream cStream = new CryptoStream(mStream, des.CreateEncryptor(Key, IV), CryptoStreamMode.Write);
 cStream.Write(inputByteArray, 0, inputByteArray.Length);
 cStream.FlushFinalBlock();
 return Convert.ToBase64String(mStream.ToArray());
 }
 /// <summary>
 /// DES解密
 /// </summary>
 /// <param name="input">待解密的字符串</param>
 /// <param name="key">解密密钥,要求为8位,和加密密钥相同</param>
 /// <returns>解密成功返回解密后的字符串,失败返源串</returns>
 public static string Decrypt(string DecryptString, byte[] Key, byte[] IV)
 {
 try
 {
 //byte[] rgbKey = Encoding.UTF8.GetBytes(Key);
 byte[] inputByteArray = Convert.FromBase64String(DecryptString);
 DESCryptoServiceProvider des = new DESCryptoServiceProvider();

 MemoryStream mStream = new MemoryStream();
 CryptoStream cStream = new CryptoStream(mStream, des.CreateDecryptor(Key, IV), CryptoStreamMode.Write);
 cStream.Write(inputByteArray, 0, inputByteArray.Length);
 cStream.FlushFinalBlock();
 return Encoding.UTF8.GetString(mStream.ToArray());
 }
 catch
 {
 return "";
 }
 }
}
/// <summary>
/// RSA加解密算法
/// </summary>
public class RSA
{
 /// <summary>
 /// RSA加密函数
 /// </summary>
 /// <param name="xmlPublicKey">说明KEY必须是XML的行式,返回的是字符串</param>
 /// <param name="EncryptString"></param>
 /// <returns></returns>
 public string Encrypt(string xmlPublicKey, string EncryptString)
 {
 byte[] PlainTextBArray;
 byte[] CypherTextBArray;
 string Result;
 RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();
 rsa.FromXmlString(xmlPublicKey);
 PlainTextBArray = (new UnicodeEncoding()).GetBytes(EncryptString);
 CypherTextBArray = rsa.Encrypt(PlainTextBArray, false);
 Result = Convert.ToBase64String(CypherTextBArray);
 return Result;
 }
 /// <summary>
 /// RSA解密函数
 /// </summary>
 /// <param name="xmlPrivateKey"></param>
 /// <param name="DecryptString"></param>
 /// <returns></returns>
 public string Decrypt(string xmlPrivateKey, string DecryptString)
 {
 byte[] PlainTextBArray;
 byte[] DypherTextBArray;
 string Result;
 RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();
 rsa.FromXmlString(xmlPrivateKey);
 PlainTextBArray = Convert.FromBase64String(DecryptString);
 DypherTextBArray = rsa.Decrypt(PlainTextBArray, false);
 Result = (new UnicodeEncoding()).GetString(DypherTextBArray);
 return Result;
 }

 /// <summary>
 /// 产生RSA的密钥
 /// </summary>
 /// <param name="xmlKeys">私钥</param>
 /// <param name="xmlPublicKey">公钥</param>
 public void RSAKey(out string xmlKeys, out string xmlPublicKey)
 {
 RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();
 xmlKeys = rsa.ToXmlString(true);
 xmlPublicKey = rsa.ToXmlString(false);
 }

Code
/// <summary>
 /// 写cookie值
 /// </summary>
 /// <param name="strName">名称</param>
 /// <param name="strValue">值</param>
 /// <param name="strValue">过期时间(分钟)</param>
 public static void WriteCookie(string strName, string strValue, int expires)
 {
 HttpCookie cookie = HttpContext.Current.Request.Cookies[strName];
 if (cookie == null)
 {
 cookie = new HttpCookie(strName);
 }
 cookie.Value = strValue;
 cookie.Expires = DateTime.Now.AddMinutes(expires);
 HttpContext.Current.Response.AppendCookie(cookie);
 }
 /// <summary>
 /// 读cookie值
 /// </summary>
 /// <param name="strName">名称</param>
 /// <returns>cookie值</returns>
 public static string GetCookie(string strName)
 {
 if (HttpContext.Current.Request.Cookies != null && HttpContext.Current.Request.Cookies[strName] != null)
 {
 return HttpContext.Current.Request.Cookies[strName].Value.ToString();
 }
 return "";
 }

Code
/// <summary>
 /// 读取配置文件
 /// </summary>
 /// <param name="Target"></param>
 /// <param name="ConfigPathName"></param>
 /// <returns></returns>
 static internal string GetConfigValue(string Target, string XmlPath)
 {
 System.Xml.XmlDocument xdoc = new XmlDocument();
 xdoc.Load(XmlPath);
 XmlElement root = xdoc.DocumentElement;
 XmlNodeList elemList = root.GetElementsByTagName(Target);
 return elemList[0].InnerXml;
 }

Code
/// <summary>
 /// 取单个字符的拼音声母
 /// </summary>
 /// <param name="c">要转换的单个汉字</param>
 /// <returns>拼音声母</returns>
 private static string GetPYChar(string c)
 {
 byte[] array = new byte[2];
 array = System.Text.Encoding.Default.GetBytes(c);
 int i = (short)(array[0] - '\0') * 256 + ((short)(array[1] - '\0'));
 if (i < 0xB0A1) return "*";
 if (i < 0xB0C5) return "A";
 if (i < 0xB2C1) return "B";
 if (i < 0xB4EE) return "C";
 if (i < 0xB6EA) return "D";
 if (i < 0xB7A2) return "E";
 if (i < 0xB8C1) return "F";
 if (i < 0xB9FE) return "G";
 if (i < 0xBBF7) return "H";
 if (i < 0xBFA6) return "G";
 if (i < 0xC0AC) return "K";
 if (i < 0xC2E8) return "L";
 if (i < 0xC4C3) return "M";
 if (i < 0xC5B6) return "N";
 if (i < 0xC5BE) return "O";
 if (i < 0xC6DA) return "P";
 if (i < 0xC8BB) return "Q";
 if (i < 0xC8F6) return "R";
 if (i < 0xCBFA) return "S";
 if (i < 0xCDDA) return "T";
 if (i < 0xCEF4) return "W";
 if (i < 0xD1B9) return "X";
 if (i < 0xD4D1) return "Y";
 if (i < 0xD7FA) return "Z";
 return "*";
 }

Code
   //字符型转换转为字符串
   12345.ToString("n");        //生成   12,345.00
   12345.ToString("C");        //生成￥12,345.00
   12345.ToString("e");        //生成 1.234500e+004
   12345.ToString("f4");        //生成 12345.0000
   12345.ToString("x");         //生成 3039  (16进制)
   12345.ToString("p");         //生成 1,234,500.00%

Code
DateTime dt = DateTime.Now;
Label1.Text = dt.ToString();//2005-11-5 13:21:25
Label2.Text = dt.ToFileTime().ToString();//127756416859912816
Label3.Text = dt.ToFileTimeUtc().ToString();//127756704859912816
Label4.Text = dt.ToLocalTime().ToString();//2005-11-5 21:21:25
Label5.Text = dt.ToLongDateString().ToString();//2005年11月5日
Label6.Text = dt.ToLongTimeString().ToString();//13:21:25
Label7.Text = dt.ToOADate().ToString();//38661.5565508218
Label8.Text = dt.ToShortDateString().ToString();//2005-11-5
Label9.Text = dt.ToShortTimeString().ToString();//13:21
Label10.Text = dt.ToUniversalTime().ToString();//2005-11-5 5:21:25
?2005-11-5 13:30:28.4412864
Label1.Text = dt.Year.ToString();//2005
Label2.Text = dt.Date.ToString();//2005-11-5 0:00:00
Label3.Text = dt.DayOfWeek.ToString();//Saturday
Label4.Text = dt.DayOfYear.ToString();//309
Label5.Text = dt.Hour.ToString();//13
Label6.Text = dt.Millisecond.ToString();//441
Label7.Text = dt.Minute.ToString();//30
Label8.Text = dt.Month.ToString();//11
Label9.Text = dt.Second.ToString();//28
Label10.Text = dt.Ticks.ToString();//632667942284412864
Label11.Text = dt.TimeOfDay.ToString();//13:30:28.4412864
Label1.Text = dt.ToString();//2005-11-5 13:47:04
Label2.Text = dt.AddYears(1).ToString();//2006-11-5 13:47:04
Label3.Text = dt.AddDays(1.1).ToString();//2005-11-6 16:11:04
Label4.Text = dt.AddHours(1.1).ToString();//2005-11-5 14:53:04
Label5.Text = dt.AddMilliseconds(1.1).ToString();//2005-11-5 13:47:04
Label6.Text = dt.AddMonths(1).ToString();//2005-12-5 13:47:04
Label7.Text = dt.AddSeconds(1.1).ToString();//2005-11-5 13:47:05
Label8.Text = dt.AddMinutes(1.1).ToString();//2005-11-5 13:48:10
Label9.Text = dt.AddTicks(1000).ToString();//2005-11-5 13:47:04
Label10.Text = dt.CompareTo(dt).ToString();//0
//Label11.Text = dt.Add(?).ToString();//问号为一个时间段
Label1.Text = dt.Equals("2005-11-6 16:11:04").ToString();//False
Label2.Text = dt.Equals(dt).ToString();//True
Label3.Text = dt.GetHashCode().ToString();//1474088234
Label4.Text = dt.GetType().ToString();//System.DateTime
Label5.Text = dt.GetTypeCode().ToString();//DateTime

Label1.Text = dt.GetDateTimeFormats('s')[0].ToString();//2005-11-05T14:06:25
Label2.Text = dt.GetDateTimeFormats('t')[0].ToString();//14:06
Label3.Text = dt.GetDateTimeFormats('y')[0].ToString();//2005年11月
Label4.Text = dt.GetDateTimeFormats('D')[0].ToString();//2005年11月5日
Label5.Text = dt.GetDateTimeFormats('D')[1].ToString();//2005 11 05
Label6.Text = dt.GetDateTimeFormats('D')[2].ToString();//星期六 2005 11 05
Label7.Text = dt.GetDateTimeFormats('D')[3].ToString();//星期六 2005年11月5日
Label8.Text = dt.GetDateTimeFormats('M')[0].ToString();//11月5日
Label9.Text = dt.GetDateTimeFormats('f')[0].ToString();//2005年11月5日 14:06
Label10.Text = dt.GetDateTimeFormats('g')[0].ToString();//2005-11-5 14:06
Label11.Text = dt.GetDateTimeFormats('r')[0].ToString();//Sat, 05 Nov 2005 14:06:25 GMT

Label1.Text =? string.Format("{0:d}",dt);//2005-11-5
Label2.Text =? string.Format("{0:D}",dt);//2005年11月5日
Label3.Text =? string.Format("{0:f}",dt);//2005年11月5日 14:23
Label4.Text =? string.Format("{0:F}",dt);//2005年11月5日 14:23:23
Label5.Text =? string.Format("{0:g}",dt);//2005-11-5 14:23
Label6.Text =? string.Format("{0:G}",dt);//2005-11-5 14:23:23
Label7.Text =? string.Format("{0:M}",dt);//11月5日
Label8.Text =? string.Format("{0:R}",dt);//Sat, 05 Nov 2005 14:23:23 GMT
Label9.Text =? string.Format("{0:s}",dt);//2005-11-05T14:23:23
Label10.Text = string.Format("{0:t}",dt);//14:23
Label11.Text = string.Format("{0:T}",dt);//14:23:23
Label12.Text = string.Format("{0:u}",dt);//2005-11-05 14:23:23Z
Label13.Text = string.Format("{0:U}",dt);//2005年11月5日 6:23:23
Label14.Text = string.Format("{0:Y}",dt);//2005年11月
Label15.Text = string.Format("{0}",dt);//2005-11-5 14:23:23?
Label16.Text = string.Format("{0:yyyyMMddHHmmssffff}",dt); //yyyymm等可以设置,比如Label16.Text = string.Format("{0:yyyyMMdd}",dt);

Code
using System.Runtime.InteropServices;

[DllImport("Iphlpapi.dll")]
 private static extern int SendARP(Int32 dest, Int32 host, ref Int64 mac, ref Int32 length);
 [DllImport("Ws2_32.dll")]
 private static extern Int32 inet_addr(string ip);
 protected void Page_Load(object sender, EventArgs e)
 {

 // 在此处放置用户代码以初始化页面
 try
 {
 string userip = Request.UserHostAddress;
 string strClientIP = Request.UserHostAddress.ToString().Trim();
 Int32 ldest = inet_addr(strClientIP); //目的地的ip
 Int32 lhost = inet_addr(""); //本地服务器的ip
 Int64 macinfo = new Int64();
 Int32 len = 6;
 int res = SendARP(ldest, 0, ref macinfo, ref len);
 string mac_src = macinfo.ToString("X");
 if (mac_src == "0")
 {
 if (userip == "127.0.0.1")
 Response.Write("正在访问Localhost!");
 else
 Response.Write("欢迎来自IP为" + userip + "的朋友！" + " ");
 return;
 }

 while (mac_src.Length < 12)
 {
 mac_src = mac_src.Insert(0, "0");
 }

 string mac_dest = "";

 for (int i = 0; i < 11; i++)
 {
 if (0 == (i % 2))
 {
 if (i == 10)
 {
 mac_dest = mac_dest.Insert(0, mac_src.Substring(i, 2));
 }
 else
 {
 mac_dest = "-" + mac_dest.Insert(0, mac_src.Substring(i, 2));
 }
 }
 }

 Response.Write("欢迎来自IP为" + userip + " " + ",MAC地址为" + mac_dest + "的朋友！"

 + " ");
 }
 catch (Exception err)
 {
 Response.Write(err.Message);
 }
 }

 private string GetClientIP()
 {
 string result = HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"];
 if (null == result || result == String.Empty)
 {
 result = HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"];
 } if (null == result || result == String.Empty)
 {
 result = HttpContext.Current.Request.UserHostAddress;
 }
 return result;
 }

Code
using System;
using System.Collections.Generic;
using System.Text;
using System.Runtime.InteropServices;
namespace NetMeeting.API
{
　　public class Win32
　　{
　　　　[DllImport("user32.dll", EntryPoint = "MessageBox", ExactSpelling = false)]
　　　　public static extern int MessageBox(int hWnd, string text, string caption, uint type);
　　}
}
//客户调用:

using System;
using NetMeeting.API;
class test
{
　　public static void Main(string[] agrs)
　　{
　　　　　　Win32.MessageBox(0,"hello ,this is a c# invoke win32 api","test",2);
　　}
}

Code
//方法1
public static Bitmap CreateThumbnail(Bitmap source, int thumbWi, int thumbHi, bool maintainAspect)
 {
 // return the source image if it's smaller than the designated thumbnail
 if (source.Width < thumbWi && source.Height < thumbHi) return source;

 System.Drawing.Bitmap ret = null;
 try
 {
 int wi, hi;

 wi = thumbWi;
 hi = thumbHi;

 if (maintainAspect)
 {
 // maintain the aspect ratio despite the thumbnail size parameters
 if (source.Width > source.Height)
 {
 wi = thumbWi;
 hi = (int)(source.Height * ((decimal)thumbWi / source.Width));
 }
 else
 {
 hi = thumbHi;
 wi = (int)(source.Width * ((decimal)thumbHi / source.Height));
 }
 }

 // original code that creates lousy thumbnails
 // System.Drawing.Image ret = source.GetThumbnailImage(wi,hi,null,IntPtr.Zero);
 ret = new Bitmap(wi, hi);
 using (Graphics g = Graphics.FromImage(ret))
 {
 g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
 g.FillRectangle(Brushes.White, 0, 0, wi, hi);
 g.DrawImage(source, 0, 0, wi, hi);
 }
 }
 catch
 {
 ret = null;
 }

 return ret;
 }
//调用
using (Graphics g = Graphics.FromImage(ret))
 {
 g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
 g.FillRectangle(Brushes.White, 0, 0, wi, hi);
 g.DrawImage(source, 0, 0, wi, hi);
 }

Code
//保存文件到SQL Server数据库中
    private void FileToSql(string fileName,string tableName,string fieldName)
    {
        SqlConnection cn=new SqlConnection ();
        FileInfo fi=new FileInfo(fileName);
        FileStream fs=fi.OpenRead();
        byte[] bytes=new byte[fs.Length];
        fs.Read(bytes,0,Convert.ToInt32(fs.Length));
        SqlCommand cm=new SqlCommand();
        cm.Connection=cn;
        cm.CommandType=CommandType.Text;
        if(cn.State==0) cn.Open();
        cm.CommandText="insert into "+tableName+"("+fieldName+") values(@file)";
        SqlParameter spFile=new SqlParameter("@file",SqlDbType.Image);
        spFile.Value=bytes;
        cm.Parameters.Add(spFile);
        cm.ExecuteNonQuery();
    }
//保存文件到Access数据库中
    private void FileToAccess(string fileName,string tableName,string fieldName)
    {
        OleDbConnection cn=new OleDbConnection ();
        FileInfo fi=new FileInfo(fileName);
        FileStream fs=fi.OpenRead();
        byte[] bytes=new byte[fs.Length];
        fs.Read(bytes,0,Convert.ToInt32(fs.Length));
        OleDbCommand cm=new OleDbCommand();
        cm.Connection=cn;
        cm.CommandType=CommandType.Text;
        if(cn.State==0) cn.Open();
        cm.CommandText="insert into "+tableName+"("+fieldName+") values(@file)";
        OleDbParameter spFile=new OleDbParameter("@file",OleDbType.Binary);
        spFile.Value=bytes;
        cm.Parameters.Add(spFile);
        cm.ExecuteNonQuery();
    }
    //保存客户端文件到数据库,fl_name为上传控件
    private void FileToDataSourse(string mailid)
    {
        string ConnStr = "";
        string sql = "update t_mail set attachfilename=@attachfilename,attachfile=@attachfile where mailid=" + mailid;
        SqlCommand myCommand = new SqlCommand(sql, new SqlConnection(ConnStr));
        string path = fl_name.PostedFile.FileName;
        string filename = path.Substring(path.LastIndexOf("") + 1, path.Length - path.LastIndexOf("") - 1);
        myCommand.Parameters.Add("@attachfilename", SqlDbType.VarChar);
        myCommand.Parameters["@attachfilename"].Value = filename;
        myCommand.Parameters.Add("@attachfile", SqlDbType.Image);
        Stream fileStream = fl_name.PostedFile.InputStream;
        int intFileSize = fl_name.PostedFile.ContentLength;
        byte[] fileContent = new byte[intFileSize];
        int intStatus = fileStream.Read(fileContent, 0, intFileSize); //文件读取到fileContent数组中
        myCommand.Parameters["@attachfile"].Value = ((byte[])fileContent);
        fileStream.Close();
        myCommand.Connection.Open();
        myCommand.ExecuteNonQuery();
        myCommand.Connection.Close();
    }

Code
public static string ConvertStr(string inputString)
 {
 string retVal = inputString;
 retVal = retVal.Replace("&", "&");
 retVal = retVal.Replace("\"", """);
 retVal = retVal.Replace("<", "<");
 retVal = retVal.Replace(">", ">");
 retVal = retVal.Replace(" ", " ");
 retVal = retVal.Replace(" ", "  ");
 retVal = retVal.Replace("\t", "  ");
 retVal = retVal.Replace("\r", " ");
 return retVal;
 }

 private static string FetchURL(string strMessage)
 {
 string strPattern = @"(?<url>(http|ftp|mms|rstp|news|https)://(?:[\w-]+\.)+[\w-]+(?:/[\w-./?%&~=]*[^.\s|,|\)|<|!])?)";
 string strReplace = "<a href=\"${url}\" target=_blank>${url}</a>";
 string strInput = strMessage;
 string strResult;
 strResult = Regex.Replace(strInput, strPattern, strReplace);
 strPattern = @"(?<!http://)(?<url>www\.(?:[\w-]+\.)+[\w-]+(?:/[\w-./?%&~=]*[^.\s|,|\)|<|!])?)";
 strReplace = "<a href=\"http://${url}\" target=_blank>${url}</a>";
 strResult = Regex.Replace(strResult, strPattern, strReplace);
 return strResult;
 }

 public string ToUrl(string inputString)
 {
 string retVal = inputString;
 retVal = ConvertStr(retVal);
 retVal = FetchURL(retVal);
 return retVal;
 }

Code

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