the jackol's den » C#/.NET

URL Routing problem with ASP.NET 4 on GoDaddy IIS 7

Mikhail Esteves — Wed, 23 Mar 2011 20:37:37 +0000

If you get 404 errors when trying to add URL Routing with ASP.NET 4 (Web Forms) on GoDaddy, simply reference the relevant modules in your web.config file:

    <modules runAllManagedModulesForAllRequests="true"> 
      <remove name="UrlRoutingModule" /> 
      <add name="UrlRoutingModule" type="System.Web.Routing.UrlRoutingModule, System.Web, 
        Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" /> 
    </modules> 
    <handlers> 
      <add name="UrlRoutingHandler" 
        preCondition="integratedMode" 
        verb="*" path="UrlRouting.axd" 
        type="System.Web.HttpForbiddenHandler, System.Web,  
        Version=2.0.0.0, Culture=neutral,  
        PublicKeyToken=b03f5f7f11d50a3a"/> 
    </handlers>

Add this to the system.webServer node.

LINQ to SQL log to debug window, file, memory or multiple writers

Mikhail Esteves — Thu, 05 Aug 2010 13:46:06 +0000

From here

class DebugTextWriter : System.IO.TextWriter {
   public override void Write(char[] buffer, int index, int count) {
       System.Diagnostics.Debug.Write(new String(buffer, index, count));
   }

   public override void Write(string value) {
       System.Diagnostics.Debug.Write(value);
   }

   public override Encoding Encoding {
       get { return System.Text.Encoding.Default; }
   }
}

Prevent One Click Attacks by setting ViewStateUserKey in ASP.NET applications

Mikhail Esteves — Sun, 13 Sep 2009 20:11:08 +0000

Here’s an easy way to avoid One Click Attacks in ASP.NET applications. If you have a Base class that all your ASP.NET pages derive from, override the OnInit function. For example:

protected override void OnInit(EventArgs e)
{
    base.OnInit(e);

    if (User.Identity.IsAuthenticated)
        ViewStateUserKey = User.Identity.Name;
}

If you don’t have a base class defined, you would have to put the above code in every ASP.NET page.

Encrypt your config please…

Raghu — Thu, 23 Jul 2009 07:34:26 +0000

ASP.NET 2.0 makes encrypting configSections in the web.config file a snap and there is no reason to not encrypt sensitive configSections. Just google for “encrypt config” and there are tons of code snippets waiting for you to copy and paste. Below is a code snippet that is found most commonly in google search results for protecting and unprotecting web.config file:

private void ProtectSection(string sectionName, string provider)

{
    Configuration config = WebConfigurationManager.OpenWebConfiguration(Request.ApplicationPath);

    ConfigurationSection section = config.GetSection(sectionName);

    if (section != null && !section.SectionInformation.IsProtected)
    {
        section.SectionInformation.ProtectSection(provider);
        config.Save();
    }
}
private void UnProtectSection(string sectionName)
{
    Configuration config = WebConfigurationManager.OpenWebConfiguration(Request.ApplicationPath);

    ConfigurationSection section = config.GetSection(sectionName);

    if (section != null && section.SectionInformation.IsProtected)
    {
        section.SectionInformation.UnprotectSection();
        config.Save();
    }
}

You would usually call ProtectSection method in the Application_Start event in global.asax. As you can see, it accepts two parameters, sectionName (like “connectionStrings”) and provider which is basically an encryption services provider. ASP.NET ships with 2 default providers:

The Windows Data Protection API (DPAPI) Provider (DataProtectionConfigurationProvider) If you use this provider then the encryption keys are provided by the Windows OS. You don’t need to maintain the keys. However, this also means that you will need to deploy you application initially with a plain-text config file and then wait for your application logic to actually encrypt it.

RSA Protected Configuration Provider (RSAProtectedConfigurationProvider) If you use this options then you are also required to create key containers to hold the public and private keys used for encrypting and decrypting the config information.

Once the data is encrypted, you don’t need to change anything in your code while accessing the settings. The ASP.NET configuration classes are smart enough to decrypt and provide you plain-text when they come across encrypted configSections. Pretty cool eh!

Please note that you may never need to invoke the UnprotectSection method. It is only provided, just in case you want to revert back to a plain-text config file.

For a complete detailed tutorial on encrypting configSections see http://aspnet.4guysfromrolla.com/articles/021506-1.aspx

ASP.NET AJAX CalendarExtender losing styles

Mikhail Esteves — Mon, 22 Jun 2009 20:01:35 +0000

If the AJAX CalendarExtender control shows up without any style information or in the wrong places, the simplest solution is to copy the original CSS for the Calendar’s default style (located at AjaxControlToolkit\Calendar\Calendar.css into your application’s CSS file. Also make sure the CssClass property is not defined in your CalendarExtender. The actual content of the default Calendar style is below:

.ajax__calendar_container {padding:4px;position:absolute;cursor:default;width:170px;
    font-size:11px;text-align:center;font-family:tahoma,verdana,helvetica;}
.ajax__calendar_body {height:139px;width:170px;position:relative;overflow:hidden;
    margin:auto;}
.ajax__calendar_days, .ajax__calendar_months, .ajax__calendar_years {top:0px;left:0px;
    height:139px;width:170px;position:absolute;text-align:center;margin:auto;}
.ajax__calendar_container TABLE {font-size:11px;}
.ajax__calendar_header {height:20px;width:100%;}
.ajax__calendar_prev {cursor:pointer;width:15px;height:15px;float:left;
    background-repeat:no-repeat;background-position:50% 50%;
    background-image:url(< %=WebResource("AjaxControlToolkit.Calendar.arrow-left.gif")%>);}
.ajax__calendar_next {cursor:pointer;width:15px;height:15px;float:right;
    background-repeat:no-repeat;background-position:50% 50%;
    background-image:url(< %=WebResource("AjaxControlToolkit.Calendar.arrow-right.gif")%>);}
.ajax__calendar_title {cursor:pointer;font-weight:bold;}
.ajax__calendar_footer {height:15px;}
.ajax__calendar_today {cursor:pointer;padding-top:3px;}
.ajax__calendar_dayname {height:17px;width:17px;text-align:right;padding:0 2px;}
.ajax__calendar_day {height:17px;width:18px;text-align:right;padding:0 2px;cursor:pointer;}
.ajax__calendar_month {height:44px;width:40px;text-align:center;cursor:pointer;overflow:hidden;}
.ajax__calendar_year {height:44px;width:40px;text-align:center;cursor:pointer;overflow:hidden;}

.ajax__calendar .ajax__calendar_container {border:1px solid #646464;background-color:#ffffff;
    color:#000000;}
.ajax__calendar .ajax__calendar_footer {border-top:1px solid #f5f5f5;}
.ajax__calendar .ajax__calendar_dayname {border-bottom:1px solid #f5f5f5;}
.ajax__calendar .ajax__calendar_day {border:1px solid #ffffff;}
.ajax__calendar .ajax__calendar_month {border:1px solid #ffffff;}
.ajax__calendar .ajax__calendar_year {border:1px solid #ffffff;}

.ajax__calendar .ajax__calendar_active .ajax__calendar_day {background-color:#edf9ff;
    border-color:#0066cc;color:#0066cc;}
.ajax__calendar .ajax__calendar_active .ajax__calendar_month {background-color:#edf9ff;
    border-color:#0066cc;color:#0066cc;}
.ajax__calendar .ajax__calendar_active .ajax__calendar_year {background-color:#edf9ff;
    border-color:#0066cc;color:#0066cc;}

.ajax__calendar .ajax__calendar_other .ajax__calendar_day {background-color:#ffffff;
    border-color:#ffffff;color:#646464;}
.ajax__calendar .ajax__calendar_other .ajax__calendar_year {background-color:#ffffff;
    border-color:#ffffff;color:#646464;}

.ajax__calendar .ajax__calendar_hover .ajax__calendar_day {background-color:#edf9ff;
    border-color:#daf2fc;color:#0066cc;}
.ajax__calendar .ajax__calendar_hover .ajax__calendar_month {background-color:#edf9ff;
    border-color:#daf2fc;color:#0066cc;}
.ajax__calendar .ajax__calendar_hover .ajax__calendar_year {background-color:#edf9ff;
    border-color:#daf2fc;color:#0066cc;}

.ajax__calendar .ajax__calendar_hover .ajax__calendar_title {color:#0066cc;}
.ajax__calendar .ajax__calendar_hover .ajax__calendar_today {color:#0066cc;}

Get LINQ to SQL results into a DataTable

Mikhail Esteves — Tue, 02 Jun 2009 08:33:09 +0000

There are two ways to get LINQ to SQL results into a DataTable, as explained here.

I use Sample II:

public DataTable ToDataTable(System.Data.Linq.DataContext ctx, object query)
{
     if (query == null)
     {
          throw new ArgumentNullException("query");
     }

     IDbCommand cmd = ctx.GetCommand(query as IQueryable);
     SqlDataAdapter adapter = new SqlDataAdapter();
     adapter.SelectCommand = (SqlCommand)cmd;
     DataTable dt = new DataTable("sd");

     try
     {
          cmd.Connection.Open();
          adapter.FillSchema(dt, SchemaType.Source); 
          adapter.Fill(dt);
     }
     finally
     {
          cmd.Connection.Close();
     }
     return dt;
}

Autostarting your WinForms application

Mikhail Esteves — Sun, 25 May 2008 16:45:15 +0000

Here’s a helper function to add your Winforms application to the Windows startup list:

public static void AddAutoStartProgram(string name, string appPath)
{
  string runKeyBase = @"Software\Microsoft\Windows\CurrentVersion\Run\";
  RegistryKey rk = Registry.CurrentUser
    .OpenSubKey(runKeyBase + name);

  if (rk == null)
  {
    RegistryKey runKey = Registry.CurrentUser
        .CreateSubKey(runKeyBase);
    runKey.SetValue(name, appPath);
    runKey.Close();
  }
  else
  {
    rk.SetValue(name, appPath);
    rk.Close();
  }
}

Usage is simple: AddAutoStartProgram("myapp", Application.ExecutablePath);

To remove a program from automatically starting up, just delete the key:

public static void RemoveAutoStartProgram(string name)
  {
  string runKeyBase = @"Software\Microsoft\Windows\CurrentVersion\Run";

  RegistryKey rk = Registry.CurrentUser.OpenSubKey(runKeyBase, true);
  rk.DeleteValue(name, false);
  rk.Close();
  }

Remove your app with a call like RemoveAutoStartProgram("myapp");

WinForms ComboBox with values like the WebForms DropDownList

Mikhail Esteves — Thu, 17 Jan 2008 02:47:40 +0000

Want to have values for each ComboBox item in WinForms? Here is a simple way of doing so. Add a class in your project named ComboBoxItem:

public class ComboBoxItem
{
  private string _value;
  private string _text;

  public string Value { get { return _value; } }
  public string Text  { get { return _text ; } }

  public ComboBoxItem (string cValue, cText)
  {
    this._value = cValue;
    this._text  = cText;
  }
}

Now when adding items to the ComboBox, you would do this:

ComboBox myBox = new ComboBox ();
myBox.Items.Add (new ComboBoxItem ("1", "January"));
myBox.Items.Add (new ComboBoxItem ("2", "February"));

myBox.DisplayMember = "Text"; // Specifies what to display
this.Controls.Add (myBox);

To retrieve the current selected value and text, you could do:

string SelectedItemValue = (myBox.SelectedItem as ComboBoxItem).Value;
string SelectedItemText  = (myBox.SelectedItem as ComboBoxItem).Text;