asp.net string Handling Class Code _ Practical Tips

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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) *?>) "," \ 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&AMP;*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&AMP;*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;
}
}
}