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Encryption and Decryption of strings with C#

Well I am checking out the Beale Street Historic District for the first time in Memphis, TN tonight. I have heard a lot about it since my arrival here so am excited to get to go. I think it will be fun.

Of course this would come up. I had written this previously in vb.net and I had the opportunity to use it again today. Of course in doing so, I discovered a bad coding practice violation I had committed. I had failed to return a value in my function’s Catch block of my code. C# doesn’t let you off the hook so easily and will bug you till you fix it. As noted previously, topic is encryption and decryption of strings. It is straightforward but you might find it useful. Simply pass in the string you want to encrypt/decrypt and the key you want to use.

using System;
using System.IO;
using System.Text;
using System.Security.Cryptography;
public class Crypto
{
    private static TripleDESCryptoServiceProvider DES = new TripleDESCryptoServiceProvider();
    private static MD5CryptoServiceProvider MD5 = new MD5CryptoServiceProvider();
    public static byte[] MD5Hash(string value)
    {
        return MD5.ComputeHash(ASCIIEncoding.ASCII.GetBytes(value));
    }
    public static string Encrypt(string stringToEncrypt, string key)
    {
        DES.Key = Crypto.MD5Hash(key);
        DES.Mode = CipherMode.ECB;
        byte[] Buffer = ASCIIEncoding.ASCII.GetBytes(stringToEncrypt);
        return Convert.ToBase64String(DES.CreateEncryptor().TransformFinalBlock(Buffer, 0, Buffer.Length));
    }
    public static string Decrypt(string encryptedString, string key)
    {
        try
        {
            DES.Key = Crypto.MD5Hash(key);
            DES.Mode = CipherMode.ECB;
            byte[] Buffer = Convert.FromBase64String(encryptedString);
            return ASCIIEncoding.ASCII.GetString(DES.CreateDecryptor().TransformFinalBlock(Buffer, 0, Buffer.Length));
        }
        catch (Exception ex)
        {
            MessageBox.Show(“Invalid Key”, “Decryption Failed”, MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
        }
// Inserted the following ‘return’ since all code paths must return a value in C#:
        return null;
    }
}

And now it’s usage…..

public class Form1
{
    private void Button1_Click(object sender, System.EventArgs e)
    {
        string key = Microsoft.VisualBasic.Interaction.InputBox(“Enter a Key:”, “”, “”, -1, -1);
        Label1.Text = Crypto.Encrypt(TextBox1.Text, key);
        TextBox1.Clear();
    }
    private void Button2_Click(object sender, System.EventArgs e)
    {
        string key = Microsoft.VisualBasic.Interaction.InputBox(“Enter a Key:”, “”, “”, -1, -1);
        TextBox1.Text = Crypto.Decrypt(Label1.Text, key);
    }

    }


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How to make Linq and IList sort Dynamically using C#

I apologize that it has been a while. I have been extremely busy and in the time that I have been away I went through treatment for a medical issue. Needless to say I had other issues to deal with other than this blog. But I will try to publish more frequently. Today’s topic was a question from another developer which was to have have a Linq and IList sort dynamically. So long as you don’t force execution by using ToList, you can keep tacking on to your query until you are ready to actually run it. This is because much of LINQ uses “deferred execution”. For example, you could do something similar to:

var query = apps.AsQueryable()
.Select
(Application => new
{
ID = Application.ApplicationId,
Force = Application.Force.Description,
Function = Application.BusinessFunction.Description,
Category = Application.Category.Description,
SubCategory = Application.SubCategory.Description,
Name = Application.ApplicationName,
Description = Application.ApplicationDescription
}
).Take(10);

switch (sortType)
{
case “ID”:
query = query.Orderby(Application => Application.ApplicationId);
break;
case “Force”:
query = query.Orderby(Application => Application.Force);
break;
}

IList tempList = query.ToList();

As always it has been great getting your all feedback while I was gone. Thank You! Smile

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Databind ComboBox with WPF and C#

Its been a while my apologies. I have been extremely busy.

This topic came up because in existing applications data binding at design time was heavily used. I personally avoid such data binding as much as possible because well in all honesty it causes me a lot of problems later on. I realize many of you live and die with it. So don’t take it personally.

So I am converting one of these apps to XAML and WPF. They insisted I maintain a ComboBox databind. As many of you know data binding has changed a bit in WPF from your standard application. I created a property to bind the ComboBox to. I set the DataContext of the page to itself, which I like to do. It lets me expose various properties and quickly bind to them. Have a great weekend!

XAML
—-
        <ComboBox
            Height=”23″
            HorizontalAlignment=”Left”
            Margin=”10,10,0,0″
            Name=”comboBox1″
            VerticalAlignment=”Top”
            Width=”120″
            ItemsSource=”{Binding MyDataColumns}”
            DisplayMemberPath=”ColumnName”
            />
 
CODE BEHIND
—-
 
public partial class Window1 : Window
{
    public Window1()
    {
        InitializeComponent();
        LoadData();
        DataContext = this;
    }
 
    private DataTable _dataTable = null;
 
    private void LoadData()
    {
        SqlConnection cn = null;
        SqlCommand cmd = null;
        SqlDataAdapter adapter = null;
        DataSet dataSet = null;
 
        try
        {
            cn = new SqlConnection(“Data Source=MyMachine;Initial Catalog=MyDb;Integrated Security=True”);
            cmd = new SqlCommand(“select top 1 * from MyTable”, cn);
            adapter = new SqlDataAdapter(cmd);
            dataSet = new DataSet();
 
            adapter.Fill(dataSet);
 
            _dataTable = dataSet.Tables[0];
        }
        finally
        {
            if (cmd != null)
                cmd.Dispose();
 
            if (adapter != null)
                adapter.Dispose();
 
            if (dataSet != null)
                dataSet.Dispose();
 
            if (cn != null)
                cn.Dispose();
        }           
    }
 
    public IEnumerable MyDataColumns
    {
        get
        {
            return (IEnumerable)_dataTable.Columns;
        }
    }
}

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Tag Generator for Live Writer: Problems and Workarounds

One topic of emails and questions I receive are in relation to the Tag Generator, a plugin available for download, for Live Writer, a blog writing tool.

First some history. The Tag Generator was originally written over two years ago to provide myself a way to automatically generate tags for my blog posts. I got tired of doing it manually. It worked well for me so I decided to create a plugin that others could use. It uses the Microsoft Word thesaurus to verify words in the blog and their meanings. It isn’t perfect but its better than nothing. Obviously some of you agreed as over 14,000 downloads took place. However over the last couple of years, for various reasons, no work was done on this plugin and a new version of Live Writer was released. While the Tag Generator plugin still works, it does not support the options feature for plugins that came out with this version of Live Writer. In addition, as you all know, Windows Live Spaces no longer supports blogging, instead choosing to support the Word Press blogging resources. Generating these tags are obviously pointless.

You might wonder to yourself why I just don’t sit down and rewrite the plugin and be done with it. Basically it is because I am too busy at the moment to do so. I will at some point I promise. I apologize to those of you who have been frustrated. But this blog post today is to tell you how I still make use of this plugin and how  you can too.

First after you are done writing your post, right click on your document and click select all.

image

Then click “Insert” in the Live Writer toolbar and click “Generate Tags”.

image

Click the option or options you wish to generate the tags for and click the button “Generate”

image

Add, modify or delete the tags you wish…..but do not click the Insert button at the bottom! Instead select all of the words in the “Tags” text box and copy them. Then in the Set tags text box at the top of Live Writer, paste these words in their textbox.

image

Now your post will be tag ready for publication whenever you choose!

I am sorry for the hassle. I still find this plugin extremely useful for me and I promise I will get around to redoing it for you at some point. But this works fine for me for now and hopefully will for you as well.

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