Marten’s blog

Today I found, that storing connection strings were little bit changed between .NET 2.0 and .NET 3.5.

Here is an example of how to store a database connection string in the application’s Web.Config file for .NET 2.0. The code for accessing the connection string is located in the C# code below.

.NET 2.0

<appSettings>
<add key="ConnectionString" value="server=localhost;database=TestDB;uid=sa;password=secret;" />
</appSettings>

And here is the C# code how to get it.

using System.Configuration;

public class TestGetConnection
{
  public TestGetConnection()
  {
    try
    {
      // Get connection string from Web.Config
      string strConnection = ConfigurationSettings.AppSettings("ConnectionString");
    }
  }
}

.NET 3.5

ConfigurationSettings.AppSettings is now deprecated.

<connectionStrings>
  <add name="YourConnectionString" connectionString="server=localhost;database=TestDB;uid=sa;password=secret;" providerName="System.Data.SqlClient" />
  <add name="NewString" connectionString="server=localhost;database=TestDB;uid=sa;password=secret;" providerName="System.Data.SqlClient" />
</connectionStrings>

And here is the C# code how to get it.

using System.Configuration;

public class TestGetConnection
{
  public TestGetConnection()
  {
    try
    {
      // Get connection string from Web.Config
      string strConnection = ConfigurationManager.ConnectionStrings["YourConnectionString"].ConnectionString;
    }
  }
}

You can use <remove /> to delete connection setting from web.config.

<connectionStrings>
  <remove name="YourConnectionString"/>
  <add name="YourConnectionString" connectionString="server=localhost;database=TestDB;uid=sa;password=secret;" providerName="System.Data.SqlClient" />
</connectionStrings>

Connection String Syntax Notes

• Values may be delimited by single or double quotes, (for example, name=’value’ or name=”value”). Either single or double quotes may be used within a connection string by using the other delimiter, for example, name=”value’s” or name=’value”s’,but not name=’value’s’ or name=”"value”". The value type is irrelevant.
• All blank characters, except those placed within a value or within quotes, are ignored.
• Keyword value pairs must be separated by a semicolon ( ; ). If a semicolon is part of a value, it also must be delimited by quotes.
• Names are not case sensitive. If a given name occurs more than once in the connection string, the value associated with the last occurence is used.
• No escape sequences are supported.

If you need to connect to SQL Express, you shold use connection string with specifying the file you want to attach.

connectionString="Server=.\SQLExpress;AttachDbFilename=c:\Program Files\Microsoft SQL Server\MSSQL.1\MSSQL\DATA\SpamTestimonial.mdf;Database=SpamTestimonial;Trusted_Connection=Yes;"

If you need to find all possible connection string, go to web page dedicated to them for more databases than you can image. http://www.connectionstrings.com/

.NET .NET, C#, Connection String, Database, SQL

When I started developing web controls which are created by CreateChildControls method i run into problem that this control is surrounded by span tag.

[ToolboxData("<{0}:ExtendedLabel runat=\"server\" Text=\"Label\" />")]
public class ExtendedLabel : WebControl, INamingContainer
{
  protected override void CreateChildControls()
  {
    Label label = new Label();
    label.Text = this.Text;
    this.Controls.Add (label);
  }
}

This example will product not so nice HTML code:

<span id=”ExtendedLabel”>
  <span name=”ExtendedLabel:Label”>Test string</span>
</span>

The first label come from RenderBeginTag method which contains by default span tag. What you can do is to override both RenderBeginTag and RenderEndTag.

protected override void RenderBeginTag(HtmlTextWriter writer)
{
  writer.Text = writer.Text + "<div id=\"myTag\">";
}
protected override void RenderBeginTag(HtmlTextWriter writer)
{
  writer.Text = writer.Text + "</div>";
}

Or remove this tag completely by overriding Render method.

Original:

protected override void Render(HtmlTextWriter writer)
{
  this.RenderBeginTag(writer);
  this.RenderContents(writer);
  this.RenderEndTag(writer);
}

New:

protected override void Render(HtmlTextWriter writer)
{
  this.RenderContents(writer);
}

In these examples you have full control over behavior of the control. These is another possibility how to change or remove the outlining tag. You can extend your web control from another class.

protected ExtendedLabel () : base()
{ }

.NET, C# .NET, C#, Web development, WebControl