.NET开发中你可能会用到的常用方
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学习.NET有一些时间了,平日积累了一些自己认为比较实用的方法(有自己写的,也有学习别人的),可能会在不同的项目开发中使用到。分享给大家,有什么好的方法还会不断添加,个别方法你可能认为很菜,仅提供给新手。当然,实现功能的方法并不唯一,这里仅供大家参考。
将文件转换成字符串,常用于读取网站模板
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/// <summary>
/// 将文件转换成字符串,常用于读取网站模板
/// </summary>
/// <param name="path"></param>
/// <param name="isSpace"></param>
/// <returns></returns>
public static string GetTempleContent(string path)
{
string result = string.Empty;
string sFileName = HttpContext.Current.Server.MapPath(path);
if (File.Exists(sFileName))
{
try
{
using (StreamReader sr = new StreamReader(sFileName))
{
result = sr.ReadToEnd();
}
}
catch
{
result = "读取模板文件(" + path + ")出错";
}
}
else
{
result = "找不到模板文件:" + path;
}
return result;
}
读取,添加,修改xml文件
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/// <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;
}
}
取得文件扩展名
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/// <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];
}
替换文本中的空格和换行
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/// <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", "<BR />");
return s;
}
验证码实现方法
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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();
}
文件创建、复制、移动、删除
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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"));
去掉结尾,
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/// <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;
}
}
}
生成任意位数的随机数
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/// <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();
实现文件的上传
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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;
}
}
判断输入是否为日期类型
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/// <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;
}
}
}
MD5加密字符串处理
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/// <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);
}
过滤非法字符,防止注入式攻击等
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/// <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;
}
常用的加密解密(DES,RSA)
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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);
}
写入读取Cookie值
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/// <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 "";
}
读取配置文件的节点内容
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/// <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;
}
取单个字符的拼音声母
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/// <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 "*";
}
变量.ToString()
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//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%
时间的处理
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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);
获得ip和mac地址
![](https://www.cnblogs.com/Images/OutliningIndicators/ContractedBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif)
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!" + "<br>");
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 + "<br>" + ",MAC地址为" + mac_dest + "的朋友!"
+ "<br>");
}
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;
}
调用Win32 Api函数,非托管DLL
![](https://www.cnblogs.com/Images/OutliningIndicators/ContractedBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif)
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);
}
}
生成高质量缩略图
![](https://www.cnblogs.com/Images/OutliningIndicators/ContractedBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif)
//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);
}
将文件保存到数据库中
![](https://www.cnblogs.com/Images/OutliningIndicators/ContractedBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif)
//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();
}
将用户输入的字符串转换为可换行、替换Html编码、无危害数据库特殊字符、去掉首尾空白、的安全方便代码
![](https://www.cnblogs.com/Images/OutliningIndicators/ContractedBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif)
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", "<br>");
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;
}