WinForm Small program------encryption and decryption, CryptoStream () use

One:

Two: Code

Main interface Code

usingSystem;usingSystem.Collections.Generic;usingSystem.ComponentModel;usingSystem.Data;usingSystem.Drawing;usingSystem.Linq;usingSystem.Text;usingSystem.Windows.Forms;namespacestringencrypt{ Public Partial classFrm_main:form { PublicFrm_main () {InitializeComponent (); }        Private voidBtn_encrypt_click (Objectsender, EventArgs e) {            if(Txt_password. Text.length = =4)//determine if the encryption key length is correct            {                Try{Txt_encryptstr.text=//Call instance Toencrypt method to get the encrypted string                        NewEncrypt (). Toencrypt (Txt_password. Text, Txt_str.                    Text); //Encrypt p_encrypt = new Encrypt (); //p_encrypt.toencrypt (""                }                Catch(Exception ex)//Catching exceptions{MessageBox.Show (ex. Message);//Output Exception Information                }            }            Else{MessageBox.Show ("Key length does not match! ","Tips");//The user is prompted to enter the key length incorrectly            }        }        Private voidBtn_unencrypt_click (Objectsender, EventArgs e) {            if(Txt_password2. Text.length = =4)//determine if the encryption key length is correct            {                Try{txt_str2. Text=//call the Todecrypt method to get the decrypted string                        NewEncrypt (). Todecrypt (Txt_password2.                Text, Txt_encryptstr2.text); }                Catch(Exception ex)//Catching exceptions{MessageBox.Show (ex. Message);//Output Exception Information                }            }            Else{MessageBox.Show ("Key length does not match! ","Tips");//The user is prompted to enter the key length incorrectly            }        }    }}

Encrypt and decrypt class code

usingSystem;usingSystem.Collections.Generic;usingSystem.IO;usingSystem.Linq;usingSystem.Security.Cryptography;usingSystem.Text;namespacestringencrypt{ Public classEncrypt {/// <summary>        ///Encrypt/// </summary>        /// <param name= "Encryptkey" >secret key</param>        /// <param name= "str" >Information</param>        /// <returns></returns>        Internal stringToencrypt (stringEncryptkey,stringstr) {            Try            {                byte[] P_byte_key =//converting a key string to a sequence of bytesEncoding.Unicode.GetBytes (Encryptkey); byte[] P_byte_data =//Convert a string to a sequence of bytesEncoding.Unicode.GetBytes (str); MemoryStream P_stream_ms=//Create a memory stream object                    NewMemoryStream (); CryptoStream P_cryptstream_stream=//creating an encrypted stream object                    NewCryptoStream (P_stream_ms,NewDESCryptoServiceProvider ().                CreateEncryptor (P_byte_key, P_byte_key), cryptostreammode.write); P_cryptstream_stream.write (//writes a sequence of bytes to an encrypted streamP_byte_data,0, P_byte_data.                Length); P_cryptstream_stream.flushfinalblock ();//presses the data into the underlying stream, updates the underlying data source or repository with the current state of the buffer, and then clears the buffer.                 byte[] P_bt_temp =//get a sequence of bytes from a memory streamP_stream_ms.                ToArray (); P_cryptstream_stream.close ();//Close Encrypted StreamP_stream_ms. Close ();//close the memory stream                return //method returns the encrypted stringconvert.tobase64string (p_bt_temp); }            Catch(cryptographicexception CE) {Throw NewException (CE.            Message); }        }        Internal stringTodecrypt (stringEncryptkey,stringstr) {            Try            {                byte[] P_byte_key =//converting a key string to a sequence of bytesEncoding.Unicode.GetBytes (Encryptkey); byte[] P_byte_data =//converts the encrypted string to a sequence of bytesconvert.frombase64string (str); MemoryStream P_stream_ms=//Create a memory stream object and write data                    NewMemoryStream (P_byte_data); CryptoStream P_cryptstream_stream=//creating an encrypted stream object                    NewCryptoStream (P_stream_ms,NewDESCryptoServiceProvider ().                CreateDecryptor (P_byte_key, P_byte_key), cryptostreammode.read); byte[] P_bt_temp =New byte[ $];//creating a byte sequence objectMemoryStream p_memorystream_temp=//Create a memory stream object                    NewMemoryStream (); inti =0;//Creating the Registers                 while((i = P_cryptstream_stream.read (//use while loop to get decrypted dataP_bt_temp,0, P_bt_temp. Length)) >0)//(1\ reads 200 bytes from the current stream-and stores them in the p_bt_temp byte offset in 2\p_bt_temp-stores the total number of bytes read from the current stream 3\ read into the buffer, starting at that offset){p_memorystream_temp. Write (//put the decrypted data into the memory streamP_bt_temp,0, i); }                return //method returns the decrypted stringEncoding.Unicode.GetString (p_memorystream_temp.            ToArray ()); }            Catch(cryptographicexception CE) {Throw NewException (CE.            Message); }        }    }}