C# Using a Class In My Winforms Application

Question

Hello everyone I am developing a chat application for school. Its in C#, a language I have never worked with before. Now I have a winform that needs to encrypt some data, I have the encryption code in is own class but for some reason I can't use any of the functions in the cipher class.

Here is a very simplified version of the code.

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq; 
using System.Text;
using System.Windows.Forms;

using System.IO;
using System.Data;
using System.Security.Cryptography;

namespace WindowsFormsApplication2
{


public class SimpleAES
{
    // Change these keys
    private byte[] Key = { 123, 217, 19, 11, 24, 26, 85, 45, 114, 184, 27, 162, 37, 112, 222, 209, 241, 24, 175, 144, 173, 53, 196, 29, 24, 26, 17, 218, 131, 236, 53, 209 };
    private byte[] Vector = { 146, 64, 191, 111, 23, 3, 113, 119, 231, 121, 252, 112, 79, 32, 114, 156 };


    private ICryptoTransform EncryptorTransform, DecryptorTransform;
    private System.Text.UTF8Encoding UTFEncoder;

    public SimpleAES()
    {
        //This is our encryption method
        RijndaelManaged rm = new RijndaelManaged();

        //Create an encryptor and a decryptor using our encryption method, key, and vector.
        EncryptorTransform = rm.CreateEncryptor(this.Key, this.Vector);
        DecryptorTransform = rm.CreateDecryptor(this.Key, this.Vector);

        //Used to translate bytes to text and vice versa
        UTFEncoder = new System.Text.UTF8Encoding();
    }

    /// -------------- Two Utility Methods (not used but may be useful) -----------
    /// Generates an encryption key.

    public byte[] Encrypt(string TextValue)
    {
        //Translates our text value into a byte array.
        Byte[] bytes = UTFEncoder.GetBytes(TextValue);

        //Used to stream the data in and out of the CryptoStream.
        MemoryStream memoryStream = new MemoryStream();

        /*
         * We will have to write the unencrypted bytes to the stream,
         * then read the encrypted result back from the stream.
         */
        #region Write the decrypted value to the encryption stream
        CryptoStream cs = new CryptoStream(memoryStream, EncryptorTransform, CryptoStreamMode.Write);
        cs.Write(bytes, 0, bytes.Length);
        cs.FlushFinalBlock();
        #endregion

        #region Read encrypted value back out of the stream
        memoryStream.Position = 0;
        byte[] encrypted = new byte[memoryStream.Length];
        memoryStream.Read(encrypted, 0, encrypted.Length);
        #endregion

        //Clean up.
        cs.Close();
        memoryStream.Close();

        return encrypted;
    }



}

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }

    private void button1_Click(object sender, EventArgs e)
    {
        byte[] result = Encrypt(textBox1.Text);


    }
}

}

When I throw this into visual studio the function call to Encrypt() is highlighted in red and the description it gives is the Encrypt does not exist in the current context.

I am much more experienced with C++ and I figured something like what I have would work, but I guess thats incorrect.

Any help would be most appreciated.

Answer 1

Make instance of SimpleAES like answer in @PoweredByOrange or change to static like @Bob or make extenstion method on a string like mine answer:

private void button1_Click(object sender, EventArgs e)
{
    byte[] result = textBox1.Text.Encrypt();
}

public class Extensionmethods
{
    public static byte[] Encrypt(this string TextValue)
    {
        //Your code here
    }
}

Answer 2

SimpleAES is not a static class, so you'll need to create an instance of it before you can call methods on it:

private void button1_Click(object sender, EventArgs e)
{
    SimpleAES simpleAes = new SimpleAES();
    byte[] result = simpleAes.Encrypt(textBox1.Text);
}