string-handling classes commonly used in asp.net

The code is as follows

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Using System; Using System.Data; Using System.Configuration; Using System.Web; Using System.Web.Security; Using System.Web.UI; Using System.Web.UI.WebControls; Using System.Web.UI.WebControls.WebParts; Using System.Web.UI.HtmlControls; Using System.Text; Namespace EC { /// Common function base class /// public class Funobject { #region Replacement string /// Features: Replacing characters /// String Replace the ' string public static string Filtersql (String strvalue) { String str = ""; str = strvalue.replace ("" "," "); return str; } #endregion #region Convert HTML operations on the contents of a table Form. /// Function: Transforms HTML operations on the contents of a table Form, /// HTML string /// public static string Htmlcode (String fstring) { String str = ""; str = fstring.replace (">", ">"); str = fstring.replace ("<", "<"); str = Fstring.replace ("", ""); str = Fstring.replace ("n", " "); str = fstring.replace ("R", " "); str = fstring.replace ("rn", " "); return str; } #endregion #region Judge whether: return value: √orx /// Judge whether: Return value: √orx /// True or False √orx public static string judgement (bool B) { string s = ""; if (b = = true) s = "√"; Else s = "X"; return s; } #endregion #region Intercept string /// ///feature: Intercept string length /// ///the string to intercept ///string length ///true: Add ..., flase: no // / public static string GetString (string str, int length, bool flg) { int i = 0, j = 0; foreach (char chr in str) { if ((int) CHR > 127) { i = 2; } Else { i++; } if (i > Length) { str = str. Substring (0, J); if (FLG) str + = "..."; break; } J + +; } return str; } #endregion #region Intercept string + ... /// Intercept string + ... /// /// /// /// public static string Cutstring (string strinput, int intlen)/intercept string { ASCIIEncoding ASCII = new ASCIIEncoding (); int intlength = 0; String strstring = ""; Byte[] s = ASCII. GetBytes (strinput); for (int i = 0; i < s.length; i++) { if ((int) s[i] = = 63) { Intlength + 2; } Else { Intlength + 1; } Try { Strstring + + strinput.substring (i, 1); } Catch { Break } if (Intlength > Intlen) { Break } } If it's truncated, add half an ellipsis. byte[] MyByte = System.Text.Encoding.Default.GetBytes (strinput); if (MyByte. Length > Intlen) { strstring + = "..."; } return strstring; } #endregion #region String Division function /// ///String Division /// /// /// /// /// public string stringsplit (str ing strings, int index, string separ) { String[] s = strings. Split (char. Parse (Separ)); return S[index]; } #endregion #region exploded string as an array /// ///string function /// ///The string to be decomposed ///delimiter, which can be a string type ///character list Public Static string[] Splitstr (String str, string splitstr) { if (splitstr!= "") { System.Collections.Array List C = new System.Collections.ArrayList (); while (true) { int thissplitindex = str. IndexOf (SPLITSTR); if (thissplitindex >= 0) { C.add (str. Substring (0, Thissplitindex)); str = str. Substring (Thissplitindex + splitstr). Length); } Else { C.add (str); break; } } string[] D = new String[c.count]; for (int i = 0; i < C.count i++) { D[i] = c[i]. ToString (); } return D; } Else { return new string[] {str}; } } #endregion #region URL Encoding /// URL encoding /// String /// public static string urlencoding (String str) { byte[] bytes = System.Text.Encoding.UTF8.GetBytes (str); Return System.Text.Encoding.UTF8.GetString (bytes). ToString (); } #endregion #region Get the Configuration field value in Web.config /// Get Global configuration parameters /// Key Name Parameters public static string Getapp (String key) { System.Configuration.AppSettingsReader appr = new System.Configuration.AppSettingsReader (); Try { String str = (string) appr. GetValue (Key, typeof (String)); if (str = NULL | | | str = = "") return null; return str; } catch (Exception E) {} return null; } #endregion #region returns a bit based on whether the passed-in string is yes/no /// Returns a bit based on whether the passed-in string is yes/no /// /// /// public static int Getbitbool (string flg) { int str = 0; Switch (FLG. ToLower ()) { Case "Yes": str = 1; Break Case "No": str = 0; Break Default Break } return str; } #endregion #region HTML Encoding /// HTML encoding /// /// /// public static string HtmlEncode (String strinput) { String str; Try { str = HttpContext.Current.Server.HtmlEncode (strinput); } Catch { str = "Error"; } return str; } /// HTML decoding /// /// /// public static string HtmlDecode (String strinput) { String str; Try { str = HttpContext.Current.Server.HtmlDecode (strinput); } Catch { str = "Error"; } return str; } #endregion #region detects whether a character character, exists in another character, exists, returns True, or returns false /// Detects a character character, whether it exists in another character, exists, returns True, or returns false /// Raw string Target string /// public static bool Isenglish (string srcstring, String aimstring) { bool Rev. = true; String Chr; if (aimstring = = "" | | Aimstring = = null) return false; for (int i = 0; i < aimstring.length; i++) { CHR = aimstring.substring (i, 1); if (Srcstring.indexof (CHR) < 0) { return false; Break } } return Rev; } #endregion #region detect if the string contains Chinese and Chinese length /// Detect if the string contains Chinese and Chinese length /// The string to detect Chinese string length public static int cnstringlength (String str) { ASCIIEncoding n = new ASCIIEncoding (); Byte[] B = n.getbytes (str); int l = 0; L is the actual length of the string for (int i = 0; I <= b.length-1; i++) { if (b[i] = = 63)//Judge whether it is Chinese character or full foot symbol { l++; } } return l; } #endregion #region take a few characters to the right of the string /// Take a few characters to the right of the string /// String Several characters to the right /// public static string Getstrright (string str, int length) { String Rev = ""; if (str. Length < length) { Rev = str; } Else { Rev = str. Substring (str. Length-length, length); } return Rev; } #endregion #region Replace the string on the right /// Replace the string on the right /// String String to the right The string to be replaced with /// public static string Repstrright (String str, string strsrc, String straim) { String Rev = ""; if (Getstrright str, strsrc. Length)!= strsrc) { Rev = str; } Else { Rev = str. Substring (0, str. Length-strsrc. Length). ToString () + Straim. ToString (); } return Rev; } #endregion } }

Example Two

Code for some common string operations! We look at the code directly!!

The code is as follows

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Using System; Namespace Web.stringutil { <summary> String Manipulation Tool Set </summary> public class Stringutil { Public Stringutil () { // TODO: Add constructor logic here // } &lt;summary&gt; Deletes the specified string from the tail in the string &lt;/summary&gt; &lt;param name= "Sourcestring" &gt;&lt;/param&gt; &lt;param name= "Removedstring" &gt;&lt;/param&gt; &lt;returns&gt;&lt;/returns&gt; public static string Remove (String sourcestring,string removedstring) { Try { if (Sourcestring.indexof (removedstring) &lt; 0) { throw new Exception ("The original string does not contain a removal string!") "); } string result = sourcestring; int lengthofsourcestring = Sourcestring.length; int lengthofremovedstring = Removedstring.length; int startIndex = lengthofsourcestring-lengthofremovedstring; String tempsubstring = Sourcestring.substring (StartIndex); if (tempsubstring.toupper () = = Removedstring.toupper ()) { result = Sourcestring.remove (startindex,lengthofremovedstring); } return result; } Catch { return sourcestring; } } &lt;summary&gt; Get the string to the right of the split break &lt;/summary&gt; &lt;param name= "Sourcestring" &gt;&lt;/param&gt; &lt;param name= "Splitchar" &gt;&lt;/param&gt; &lt;returns&gt;&lt;/returns&gt; public static string Rightsplit (String sourcestring, char Splitchar) { String Result=null; string[] tempstring = Sourcestring.split (Splitchar); if (Tempstring.length &gt;0) { result = Tempstring[tempstring.length-1]. ToString (); } return result; } &lt;summary&gt; Get the string to the left of the split break &lt;/summary&gt; &lt;param name= "Sourcestring" &gt;&lt;/param&gt; &lt;param name= "Splitchar" &gt;&lt;/param&gt; &lt;returns&gt;&lt;/returns&gt; public static string Leftsplit (String sourcestring, char Splitchar) { String Result=null; string[] tempstring = Sourcestring.split (Splitchar); if (Tempstring.length &gt;0) { result = Tempstring[0]. ToString (); } return result; } &lt;summary&gt; Remove the last comma &lt;/summary&gt; &lt;param Name= "origin" &gt;&lt;/param&gt; &lt;returns&gt;&lt;/returns&gt; public static string Dellastcomma (String origin) { if (Origin. IndexOf (",") = =-1) { return origin; } return origin. Substring (0,origin. LastIndexOf (",")); } &lt;summary&gt; Remove Invisible characters &lt;/summary&gt; &lt;param name= "Sourcestring" &gt;&lt;/param&gt; &lt;returns&gt;&lt;/returns&gt; public static string Deleteunvisiblechar (String sourcestring) { System.Text.StringBuilder Sbuilder = new System.Text.StringBuilder (131); for (int i = 0;i &lt; sourcestring.length; i++) { int Unicode = Sourcestring[i]; if (Unicode &gt;= 16) { Sbuilder.append (Sourcestring[i]. ToString ()); } } return sbuilder.tostring (); } &lt;summary&gt; Gets the merged string for an array element &lt;/summary&gt; &lt;param name= "Stringarray" &gt;&lt;/param&gt; &lt;returns&gt;&lt;/returns&gt; public static string getarraystring (string[] stringarray) { string totalstring = null; for (int i=0;i&lt;stringarray.length;i++) { totalstring = totalstring + stringarray[i]; } return totalstring; } &lt;summary&gt; Gets the number of times a string appears in a string array &lt;/summary&gt; &lt;param name= "Stringarray" type= "string[]" &gt; &lt;para&gt; /// &lt;/para&gt; &lt;/param&gt; &lt;param name= "findstring" type= "string" &gt; &lt;para&gt; /// &lt;/para&gt; &lt;/param&gt; &lt;returns&gt; A int Value &lt;/returns&gt; public static int Getstringcount (string[] stringarray,string findstring) { int count =-1; String totalstring = Getarraystring (Stringarray); string subString = totalstring; while (Substring.indexof (findstring) >=0) { subString = totalstring.substring (Substring.indexof (findstring)); Count + 1; } return count; } &lt;summary&gt; Gets the number of times a string appears in a string &lt;/summary&gt; &lt;param name= "Stringarray" type= "string" &gt; &lt;para&gt; Original string &lt;/para&gt; &lt;/param&gt; &lt;param name= "findstring" type= "string" &gt; &lt;para&gt; Match string &lt;/para&gt; &lt;/param&gt; &lt;returns&gt; Number of matching strings &lt;/returns&gt; public static int Getstringcount (string sourcestring,string findstring) { int count = 0; int findstringlength = Findstring.length; string subString = sourcestring; while (Substring.indexof (findstring) >=0) { subString = substring.substring (Substring.indexof (findstring) +findstringlength); Count + 1; } return count; } &lt;summary&gt; Intercepts all characters starting from startstring to the end of the original string &lt;/summary&gt; &lt;param name= "sourcestring" type= "string" &gt; &lt;para&gt; /// &lt;/para&gt; &lt;/param&gt; &lt;param name= "startstring" type= "string" &gt; &lt;para&gt; /// &lt;/para&gt; &lt;/param&gt; &lt;returns&gt; A String Value &lt;/returns&gt; public static string Getsubstring (String sourcestring,string startstring) { Try { int index = Sourcestring.toupper (). IndexOf (startstring); if (index&gt;0) { Return sourcestring.substring (index); } return sourcestring; } Catch { Return ""; } }         public static string getsubstring (String sourcestring,string Beginremovedstring,string endremovedstring)         {              Try              {                  if (Sourcestring.indexof (beginremovedstring)!=0)                  {                         beginremovedstring = "";                } if (Sourcestring.lastindexof (endremovedstring,sourcestring.length-endremovedstring.length) &lt;0) { endremovedstring = ""; } int startIndex = Beginremovedstring.length; int length = Sourcestring.length-beginremovedstring.length-endremovedstring.length; if (length&gt;0) { Return sourcestring.substring (startindex,length); } return sourcestring; } Catch { return sourcestring;; } } &lt;summary&gt; To remove the length of a string by number of bytes &lt;/summary&gt; &lt;param name= "Strtmp" &gt; string to be evaluated &lt;/param&gt; &lt;returns&gt; number of bytes in the string &lt;/returns&gt; public static int GetByteCount (string strtmp) { int intcharcount=0; for (int i=0;i&lt;strtmp.length;i++) { if (System.Text.UTF8Encoding.UTF8.GetByteCount (strtmp.substring (i,1)) ==3) { intcharcount=intcharcount+2; } Else { intcharcount=intcharcount+1; } } return intcharcount; } &lt;summary&gt; By number of bytes at the position of the string &lt;/summary&gt; &lt;param name= "Intins" &gt; string position &lt;/param&gt; &lt;param name= "Strtmp" &gt; string to be evaluated &lt;/param&gt; &lt;returns&gt; byte position &lt;/returns&gt; public static int Getbyteindex (int intins,string strtmp) { int intreins=0; if (Strtmp.trim () = "") { return intins; } for (int i=0;i&lt;strtmp.length;i++) { if (System.Text.UTF8Encoding.UTF8.GetByteCount (strtmp.substring (i,1)) ==3) { intreins=intreins+2; } Else { intreins=intreins+1; } if (intreins&gt;=intins) { intreins=i+1; Break } } return intreins; } } }

Example Three

The code is as follows

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Using System; Using System.Collections; Using System.Collections.Generic; Using System.Text; Using System.Text.RegularExpressions; Using System.Security.Cryptography; Using System.IO; Using System.Text; Namespace Stringclass { public class Stringhelper { <summary> Remove all spaces in a string </summary> <param name= "_str" ></param> <returns></returns> public static string Removeblank (String _str) { String strtemp = ""; Charenumerator CEnumerator = _str. GetEnumerator (); while (Cenumerator.movenext ()) { byte[] array = new BYTE[1]; Array = System.Text.Encoding.ASCII.GetBytes (CEnumerator.Current.ToString ()); int asciicode = (short) (array[0]); if (Asciicode!= 32) { strtemp + + CEnumerator.Current.ToString (); } } return strtemp; } <summary> Intercepts the string and restricts the string length more than the given length + ... </summary> <param name= "str" > the string to be intercepted </param> <param name= "Len" > length of each line, more than this length of line wrap </param> <param name= "Max" > Output string Maximum length </param> <returns></returns> public static string Cutstr (string str, int len, int max) { string s = ""; string sheng = ""; if (str. Length > Max) { str = str. Substring (0, Max); Sheng = ""; } for (int i = 0; i < str. Length; i++) { int r = i% Len; int last = (str. Length/len) * LEN; if (i!= 0 && i <= last) { if (r = = 0) { s + + str. Substring (I-len, Len) + "<br>"; } } else if (i > Last) { s + + str. Substring (i-1); Break } } return S + Sheng; } <summary> Intercepts a string, without limiting the length of the string </summary> <param name= "str" > the string to be intercepted </param> <param name= "Len" > length of each line, more than this length of line wrap </param> <returns></returns> public static string Cutstr (string str, int len) { string s = ""; for (int i = 0; i < str. Length; i++) { int r = i% Len; int last = (str. Length/len) * LEN; if (i!= 0 && i <= last) { if (r = = 0) { s + + str. Substring (I-len, Len) + "<br>"; } } else if (i > Last) { s + + str. Substring (i-1); Break } } return s; } public static string partsubstring (string str, int len) { if (str. Length > Len) { Return str. Substring (0, Len) + "..."; } return str; } <summary> This method ensures that the user's input is not malicious </summary> <param name= "Text" > Input string </param> <param name= "MaxLength" > Max length </param> <returns> the converted string </returns> public static string Inputtext (string text, int maxLength) { Text = text. Trim (); if (string. IsNullOrEmpty (text) return string. Empty; if (text. Length > MaxLength) Text = text. Substring (0, maxLength); Text = Regex.Replace (text, "[\s]{2,}", ""); Two or more spaces Text = Regex.Replace (text, "<[b| b][r| r]/*>) +| (<[p| P] (. | \ n) "," *?> "); <br> Text = Regex.Replace (text, "\s*&[n| n][b| b][s| s][p| p];\s*) + "," ");   Text = Regex.Replace (text, <. | \ n) *?> ", String. Empty); Any other tags Text = text. Replace ("'", "" "); return text; } <summary> Uppercase characters in string to lowercase </summary> <param name= "str" ></param> <returns></returns> public static string Stringtolower (String str) { char[] A = str. ToCharArray (); String strtemp = ""; for (int i = 0; i < a.length; i++) { if (Convert.ToInt32 (a[i)) >= && Convert.ToInt32 (a[i)) <= 90) strtemp + = A[i]. ToString (). ToLower (); Else strtemp + = A[i]. ToString (); } return strtemp; } <summary> Encryption </summary> <param name= "str" ></param> <param name= "Key" > must be a 8-bit string </param> <returns></returns> public static string Encode (string str, int keyIndex) { ArrayList Alkey = new ArrayList (); Alkey.add ("bookt@#+! NumBq2 "); Alkey.add ("magazine@" (21&*ID5); Alkey.add ("thesisdshi}._y"); String key = Alkey[keyindex]. ToString (); DESCryptoServiceProvider Provider = new DESCryptoServiceProvider (); Provider. Key = Encoding.ASCII.GetBytes (key. Substring (0, 8)); PROVIDER.IV = Encoding.ASCII.GetBytes (key. Substring (0, 8)); byte[] bytes = encoding.getencoding ("GB2312"). GetBytes (str); MemoryStream stream = new MemoryStream (); CryptoStream stream2 = new CryptoStream (stream, provider. CreateEncryptor (), cryptostreammode.write); Stream2. Write (bytes, 0, bytes. Length); Stream2. FlushFinalBlock (); StringBuilder builder = new StringBuilder (); foreach (Byte num in stream. ToArray ()) { Builder. AppendFormat ("{0:x2}", num); } Stream. Close (); Return builder. ToString (); } <summary> Des decryption GB2312 </summary> <param name= "str" >desc string</param> <param name= "Key" >key, must be 8-bit </param> <returns></returns> public static string Decode (string str, int keyIndex) { ArrayList Alkey = new ArrayList (); Alkey.add ("bookt@#+! NumBq2 "); Alkey.add ("magazine@" (21&*ID5); Alkey.add ("thesisdshi}._y"); String key = Alkey[keyindex]. ToString (); DESCryptoServiceProvider Provider = new DESCryptoServiceProvider (); Provider. Key = Encoding.ASCII.GetBytes (key. Substring (0, 8)); PROVIDER.IV = Encoding.ASCII.GetBytes (key. Substring (0, 8)); byte[] buffer = new BYTE[STR. LENGTH/2]; for (int i = 0; i < (str. LENGTH/2); i++) { int num2 = Convert.ToInt32 (str. Substring (i * 2, 2), 0x10); Buffer[i] = (byte) num2; } MemoryStream stream = new MemoryStream (); CryptoStream stream2 = new CryptoStream (stream, provider. CreateDecryptor (), cryptostreammode.write); Stream2. Write (buffer, 0, buffer.) Length); Stream2. FlushFinalBlock (); Stream. Close (); Return encoding.getencoding ("GB2312"). GetString (stream. ToArray ()); } <summary> MD5 32-bit irreversible encryption </summary> <param name= "S" ></param> <param name= "_input_charset" ></param> <returns></returns> public static string Getmd5_32 (String str1) { string CL1 = str1; string pwd = ""; MD5 MD5 = MD5. Create (); After encryption is an array of byte types Byte[] s = Md5.computehash (Encoding.Unicode.GetBytes (CL1)); Converts an array of byte types to a string by using a loop, which is a regular character formatting gain for (int i = 0; i < s.length; i++) { Use hexadecimal type format for the resulting string. The formatted character is a lowercase letter, and if uppercase (X) is used, the character in the format is upper case. PWD = pwd + s[i]. ToString ("X"); } return pwd; } <summary> MD5 16-bit irreversible encryption </summary> <param name= "Convertstring" ></param> <returns></returns> public static string Getmd5_16 (String convertstring) { MD5CryptoServiceProvider MD5 = new MD5CryptoServiceProvider (); String t2 = bitconverter.tostring (Md5.computehash (UTF8Encoding.Default.GetBytes (convertstring)), 4, 8); t2 = T2. Replace ("-", ""); return T2; } } }