ComboBox Doesn't Show Items

Question

All of my efforts to add items to display in the combobox fail; I've added items using the IDE in VS2003 (String Collection Editor) or programtically and all I get is an empty drop down list that gets longer.  The project compiles and I get no errors but my application only shows an empty drop down list.  Can someone please tell me what I'm doing wrong?

Answer 1

Encryption

• Sometimes we want to encrypt the values that time we use MD5 Encryption and Decryption
• Here i give the code for Encryption and Decryption.

passPhrase ,saltValue ,initVector this variables are the key for Encryption and Decryption

public static string passPhrase = "YOUR KEY1";

public static string saltValue = "YOUR KE2";

public static string initVector = "YOUR KE3";

public static string FunForEncrypt(string objText)

{

int keySize = 256;

int passwordIterations = 03;

string hashAlgorithm = "MD5";

byte[] initVectorBytes = Encoding.ASCII.GetBytes(initVector);

byte[] saltValueBytes = Encoding.ASCII.GetBytes(saltValue);

byte[] plainTextBytes = Encoding.UTF8.GetBytes(objText);

PasswordDeriveBytes password = new PasswordDeriveBytes

(

passPhrase,

saltValueBytes,

hashAlgorithm,

passwordIterations

);

byte[] keyBytes = password.GetBytes(keySize / 8);

RijndaelManaged symmetricKey = new RijndaelManaged();

symmetricKey.Mode = CipherMode.CBC;

ICryptoTransform encryptor = symmetricKey.CreateEncryptor

(

keyBytes,

initVectorBytes

);

MemoryStream memoryStream = new MemoryStream();

CryptoStream cryptoStream = new CryptoStream

(

memoryStream,

encryptor,

CryptoStreamMode.Write

);

cryptoStream.Write(plainTextBytes, 0, plainTextBytes.Length);

cryptoStream.FlushFinalBlock();

byte[] cipherTextBytes = memoryStream.ToArray();

memoryStream.Close();

cryptoStream.Close();

string cipherText = Convert.ToBase64String(cipherTextBytes);

cipherText = HttpUtility.UrlEncode(cipherText);

return cipherText;

}

Decryption :

• this below code used to Decrypt the text

public static string FunForDecrypt(string cipherText)

{

string plainText = "";

int keySize = 256;

int passwordIterations = 03;

string hashAlgorithm = "MD5";

try

{

cipherText = HttpUtility.UrlDecode(cipherText);

byte[] initVectorBytes = Encoding.ASCII.GetBytes(initVector);

byte[] saltValueBytes = Encoding.ASCII.GetBytes(saltValue);

byte[] cipherTextBytes = Convert.FromBase64String(cipherText);

PasswordDeriveBytes password = new PasswordDeriveBytes

(

passPhrase,

saltValueBytes,

hashAlgorithm,

passwordIterations

);

byte[] keyBytes = password.GetBytes(keySize / 8);

RijndaelManaged symmetricKey = new RijndaelManaged();

symmetricKey.Mode = CipherMode.CBC;

ICryptoTransform decryptor = symmetricKey.CreateDecryptor

(

keyBytes,

initVectorBytes

);

MemoryStream memoryStream = new MemoryStream(cipherTextBytes);

CryptoStream cryptoStream = new CryptoStream

(

memoryStream,

decryptor,

CryptoStreamMode.Read

);

byte[] plainTextBytes = new byte[cipherTextBytes.Length];

int decryptedByteCount = cryptoStream.Read

(

plainTextBytes,

0,

plainTextBytes.Length

);

memoryStream.Close();

cryptoStream.Close();

plainText = Encoding.UTF8.GetString(plainTextBytes, 0, decryptedByteCount);

}

catch (Exception ex)

{

plainText = "";

}

return plainText;

}

Answer 2

Use this code ,its working fine..

privatestringEncrypt(stringclearText)
{
stringEncryptionKey="MAKV2SPBNI99212";
byte[]clearBytes=Encoding.Unicode.GetBytes(clearText);
using(Aesencryptor=Aes.Create())
{
Rfc2898DeriveBytespdb=newRfc2898DeriveBytes(EncryptionKey,newbyte[]{0x49,0x76,0x61,0x6e,0x20,0x4d,0x65,0x64,0x76,0x65,0x64,0x65,0x76});
encryptor.Key=pdb.GetBytes(32);
encryptor.IV=pdb.GetBytes(16);
using(MemoryStreamms=newMemoryStream())
{
using(CryptoStreamcs=newCryptoStream(ms,encryptor.CreateEncryptor(),CryptoStreamMode.Write))
{
cs.Write(clearBytes,0,clearBytes.Length);
cs.Close();
}
clearText=Convert.ToBase64String(ms.ToArray());
}
}
returnclearText;
}
privatestringDecrypt(stringcipherText)
{
stringEncryptionKey="MAKV2SPBNI99212";
byte[]cipherBytes=Convert.FromBase64String(cipherText);
using(Aesencryptor=Aes.Create())
{
Rfc2898DeriveBytespdb=newRfc2898DeriveBytes(EncryptionKey,newbyte[]{0x49,0x76,0x61,0x6e,0x20,0x4d,0x65,0x64,0x76,0x65,0x64,0x65,0x76});
encryptor.Key=pdb.GetBytes(32);
encryptor.IV=pdb.GetBytes(16);
using(MemoryStreamms=newMemoryStream())
{
using(CryptoStreamcs=newCryptoStream(ms,encryptor.CreateDecryptor(),CryptoStreamMode.Write))
{
cs.Write(cipherBytes,0,cipherBytes.Length);
cs.Close();
}
cipherText=Encoding.Unicode.GetString(ms.ToArray());
}
}
returncipherText;
}

Answer 3

Yes . You can . 

 The best way is using your secret key you can do encryption and decryption.Copy and Paste below code into you application try to run it.

 

// This constant string is used as a "salt" value for the PasswordDeriveBytes function calls.
// This size of the IV (in bytes) must = (keysize / 8). Default keysize is 256, so the IV must be
// 32 bytes long. Using a 16 character string here gives us 32 bytes when converted to a byte array.
private static readonly byte[] initVectorBytes = Encoding.ASCII.GetBytes("tu89geji340t89u2");
// This constant is used to determine the keysize of the encryption algorithm.
private const int keysize = 256;
//Here passPhrase is your secret key. Which can be anything. but should be similar in both ecryption and decryption
public static string Encrypt(string plainText, string passPhrase)
{
try
{
byte[] plainTextBytes = Encoding.UTF8.GetBytes(plainText);
using (PasswordDeriveBytes password = new PasswordDeriveBytes(passPhrase, null))
{
byte[] keyBytes = password.GetBytes(keysize / 8);
using (RijndaelManaged symmetricKey = new RijndaelManaged())
{
symmetricKey.Mode = CipherMode.CBC;
using (ICryptoTransform encryptor = symmetricKey.CreateEncryptor(keyBytes, initVectorBytes))
{
using (MemoryStream memoryStream = new MemoryStream())
{
using (CryptoStream cryptoStream = new CryptoStream(memoryStream, encryptor, CryptoStreamMode.Write))
{
cryptoStream.Write(plainTextBytes, 0, plainTextBytes.Length);
cryptoStream.FlushFinalBlock();
byte[] cipherTextBytes = memoryStream.ToArray();
return Convert.ToBase64String(cipherTextBytes);
}
}
}
}
}
}
catch (Exception)
{
return string.Empty;
}
}
public static string Decrypt(string cipherText, string passPhrase)
{
try
{
byte[] cipherTextBytes = Convert.FromBase64String(cipherText);
using (PasswordDeriveBytes password = new PasswordDeriveBytes(passPhrase, null))
{
byte[] keyBytes = password.GetBytes(keysize / 8);
using (RijndaelManaged symmetricKey = new RijndaelManaged())
{
symmetricKey.Mode = CipherMode.CBC;
using (ICryptoTransform decryptor = symmetricKey.CreateDecryptor(keyBytes, initVectorBytes))
{
using (MemoryStream memoryStream = new MemoryStream(cipherTextBytes))
{
using (CryptoStream cryptoStream = new CryptoStream(memoryStream, decryptor, CryptoStreamMode.Read))
{
byte[] plainTextBytes = new byte[cipherTextBytes.Length];
int decryptedByteCount = cryptoStream.Read(plainTextBytes, 0, plainTextBytes.Length);
return Encoding.UTF8.GetString(plainTextBytes, 0, decryptedByteCount);
}
}
}
}
}
}
catch (Exception)
{
return string.Empty;
}
}
}