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C# setting web.config according to machine name

Is it possible to change web.config (ASP.NET c#) file depending on Environment.MachineName? For example if I am running WebApp1 on dev.internal.net machine I need a connectionstring1 and webapp2 on Prod.external.net it is connectionstring2?
Thanks
R

You can make several different connection strings like this:
<add name="dev.internal.net" connectionString="Data Source=Location DB1;Initial Catalog=DB Name;Integrated Security=True"/>
<add name="Prod.external.net" connectionString="Data Source=Location DB1;Initial Catalog=DB Name;Integrated Security=True"/>
You can make the name of the connection string as the Environment.MachineName to make it work.
Some more information is on the following link:
http://ayende.com/blog/135169/frictionless-development-web-config-and-connection-strings

Get connectionstring from web.config

I use System.Configuration.ConfigurationManager.AppSettings["key1"] in settings.designer.cs file. It's working fine in the development but after I moved all the .dll files into production it is not working.
In web.config file I added app settings in development and production both. What is the problem?
Code from settings.designer.cs file
get
{
return WebConfigurationManager.AppSettings["ConnectionString"];
//return (AppSettings["ConnectionString"]);
//return ((string)(this["ConnectionString"]));
}
I tried all three return statements. 3rd return is working fine in both dev & prod but it is not rendering from web.config.
Code in web.config
<add key="ConnectionString" value="connection string values are given here">

Don't use WebConfigurationManager.
Use System.Configuration.ConfigurationManager.AppSettings["key"] instead to read key-value pair kept in Web.config, e.g.:
<configuration>
<appSetttings>
<add key="key1" value="value1" />
</appSetttings>
</configuration>
and System.Configuration.ConfigurationManager.ConnectionStrings["name"].ConnectionString to read connection string, e.g.:
<configuration>
<connectionStrings>
<add name="name" connectionString="value1" />
</connectionStrings>
</configuration>

You have to add configuration setting (connectionstring) to last execution program config file.

How to change the value of attribute in appSettings section with Web.config transformation

Is it possible to transform the following Web.config appSettings file:
<appSettings>
<add key="developmentModeUserId" value="00297022" />
<add key="developmentMode" value="true" />
/* other settings here that should stay */
</appSettings>
into something like this:
<appSettings>
<add key="developmentMode" value="false" />
/* other settings here that should stay */
</appSettings>
So, I need to remove the key developmentModeUserId, and I need to replace the value for the key developmentMode.

You want something like:
<appSettings>
<add key="developmentModeUserId" xdt:Transform="Remove" xdt:Locator="Match(key)"/>
<add key="developmentMode" value="false" xdt:Transform="SetAttributes"
xdt:Locator="Match(key)"/>
</appSettings>
See Also: Web.config Transformation Syntax for Web Application Project Deployment

Replacing all AppSettings
This is the overkill case where you just want to replace an entire section of the web.config. In this case I will replace all AppSettings in the web.config will new settings in web.release.config. This is my baseline web.config appSettings:
<appSettings>
<add key="KeyA" value="ValA"/>
<add key="KeyB" value="ValB"/>
</appSettings>
Now in my web.release.config file, I am going to create a appSettings section except I will include the attribute xdt:Transform=”Replace” since I want to just replace the entire element. I did not have to use xdt:Locator because there is nothing to locate – I just want to wipe the slate clean and replace everything.
<appSettings xdt:Transform="Replace">
<add key="ProdKeyA" value="ProdValA"/>
<add key="ProdKeyB" value="ProdValB"/>
<add key="ProdKeyC" value="ProdValC"/>
</appSettings>
Note that in the web.release.config file my appSettings section has three keys instead of two, and the keys aren’t even the same. Now let’s look at the generated web.config file what happens when we publish:
<appSettings>
<add key="ProdKeyA" value="ProdValA"/>
<add key="ProdKeyB" value="ProdValB"/>
<add key="ProdKeyC" value="ProdValC"/>
</appSettings>
Just as we expected – the web.config appSettings were completely replaced by the values in web.release config. That was easy!

If you want to make transformation your app setting from web config file to web.Release.config,you have to do the following steps.
Let your web.config app setting file is this-
<appSettings>
<add key ="K1" value="Debendra Dash"/>
</appSettings>
Now here is the web.Release.config for the transformation.
<appSettings>
<add key="K1" value="value dynamicly from Realease"
xdt:Transform="SetAttributes"
xdt:Locator="Match(key)"
/>
</appSettings>
This will transform the value of K1 to the new value in realese Mode.

I do not like transformations to have any more info than needed. So instead of restating the keys, I simply state the condition and intention. It is much easier to see the intention when done like this, at least IMO. Also, I try and put all the xdt attributes first to indicate to the reader, these are transformations and not new things being defined.
<appSettings>
<add xdt:Locator="Condition(#key='developmentModeUserId')" xdt:Transform="Remove" />
<add xdt:Locator="Condition(#key='developmentMode')" xdt:Transform="SetAttributes"
value="false"/>
</appSettings>
In the above it is much easier to see that the first one is removing the element. The 2nd one is setting attributes. It will set/replace any attributes you define here. In this case it will simply set value to false.

How to declare a variable in the app.config file?

I am working on a Windows application.
I have a form with labels like
HOST:
UserName:
Password:
How I can declare the connection string in the app.config file so that it takes the initial catalog, userID and password as variables that I can use in further to check the user whether which database the user wants to get connected with the entered userID and password.
I am using SQL Server 2008 and Visual C# 2008 Express Edition.

As I'm reading your question, you want to have a generic connection string that you want to inject username/password variables into. To do that you would need to have a key with this format:
<add name="myDBKey" connectionString="Data Source=myDB;Initial Catalog={0};Persist Security Info=True;User ID={1};Password={2}" providerName="System.Data.SqlClient"/>
Then in your code, you would need to have these variables declared and assigned, and then use String.Format to complete it.
string dbCatalog = "myCatalog";
string dbUser = "myUser";
string dbPW = "myPW";
string myDBConnectionString = String.Format(
ConfigurationManager.ConnectionStrings["myDBKey"].ConnectionString,
dbCatalog, dbUser, dbPW);
This will inject your variables into the string.

There is a <connectionString> section to the app.config file.
<connectionStrings>
<add name="MyDatabase" connectionString="Data Source=sqlserver,1433;Network Library=DBMSSOCN;Initial Catalog=MyDatabase;User ID=xxx;Password=xxxx;" />
</connectionStrings>
For your Host, User ID and Password, you can define these in the <appSettings> section.

Try this
<connectionStrings>
<add name="ConString" connectionString="Server=Servernae;Database=DBName;User Id=username;password=yourpassword"/>
</connectionStrings>
For more information try Connection Strings

Start by declaring the variables by going to your project's property tab, then going to the Settings tab (on the left), declaring your variables by mentioning the name, default value, and scope (which will be Application).
In your code, to fetch the values:
using System.Configuration;
//....
ConfigurationSettings.AppSettings["ConnectionString"].ToString();
// or
ConfigurationSettings.AppSettings.ConnectionString;
Please note that you can't change the value in code for an Application setting.
EDIT:
Alternately, there is also the connectionStrings node which can be set (but it must be done in the app.config file itself. See MSDN for documentation.
Example of XML:
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<connectionStrings>
<add name="ConnStr1" connectionString="LocalSqlServer: data source=127.0.0.1 Integrated Security=SSPI;Initial Catalog=aspnetdb"
providerName="System.Data.SqlClient" />
</connectionStrings>
</configuration>
In C#, you will get a System.Coonfiguration.ConnectionStrings, which is a collection of ConnectionStringSettings.
Example of usage in C# code: http://msdn.microsoft.com/en-us/library/system.configuration.configurationmanager.connectionstrings.aspx

You can do some thing like this,
<appSettings>
<add key="SettingName" value="SettingValue" />
</appSettings>
or go to "Variables within app.config/web.config".

My library Expansive is designed with this as a primary use-case.
Moderate Example (using AppSettings as default source for token expansion)
In app.config:
<configuration>
<appSettings>
<add key="Domain" value="mycompany.com"/>
<add key="ServerName" value="db01.{Domain}"/>
</appSettings>
<connectionStrings>
<add name="Default" connectionString="server={ServerName};uid=uid;pwd=pwd;Initial Catalog=master;" provider="System.Data.SqlClient" />
</connectionStrings>
</configuration>
Use the .Expand() extension method on the string to be expanded:
var connectionString = ConfigurationManager.ConnectionStrings["Default"].ConnectionString;
connectionString.Expand() // returns "server=db01.mycompany.com;uid=uid;pwd=pwd;Initial Catalog=master;"
or
Use the Dynamic ConfigurationManager wrapper "Config" as follows (Explicit call to Expand() not necessary):
var serverName = Config.AppSettings.ServerName;
// returns "db01.mycompany.com"
var connectionString = Config.ConnectionStrings.Default;
// returns "server=db01.mycompany.com;uid=uid;pwd=pwd;Initial Catalog=master;"
Advanced Example 1 (using AppSettings as default source for token expansion)
In app.config:
<configuration>
<appSettings>
<add key="Environment" value="dev"/>
<add key="Domain" value="mycompany.com"/>
<add key="UserId" value="uid"/>
<add key="Password" value="pwd"/>
<add key="ServerName" value="db01-{Environment}.{Domain}"/>
<add key="ReportPath" value="\\{ServerName}\SomeFileShare"/>
</appSettings>
<connectionStrings>
<add name="Default" connectionString="server={ServerName};uid={UserId};pwd={Password};Initial Catalog=master;" provider="System.Data.SqlClient" />
</connectionStrings>
</configuration>
Use the .Expand() extension method on the string to be expanded:
var connectionString = ConfigurationManager.ConnectionStrings["Default"].ConnectionString;
connectionString.Expand() // returns "server=db01-dev.mycompany.com;uid=uid;pwd=pwd;Initial Catalog=master;"

Multiple SQL Server connection strings in app.config file

I'm interested in displaying in a Windows Forms app a list of N radio buttons for the user to choose a target database server. I would like to add the SQL Server connection strings in the app.config file, so they are read by the app at runtime and rendered in the windows form as radio buttons.
At first I thought of using a delimiter to separate the connections
<appSettings>
<add key="ConnectionString" value="connection1|user id=user;password=123;server=10.0.0.1;database=myDatabase;connection timeout=30|connection2|user id=user;password=123;server=10.0.0.2;database=myDatabase;connection timeout=30"/>
</appSettings>
And then split the key value pairs.
Is it possible to do this in a different way?

To find all defined connection strings from your app.config, use the ConfigurationManager (from System.Configuration).
It has an enumeration: ConfigurationManager.ConnectionStrings which contains all entries in your <connectionStrings>.
You can loop over it with this code:
foreach(ConnectionStringSettings css in ConfigurationManager.ConnectionStrings)
{
string name = css.Name;
string connString = css.ConnectionString;
string provider = css.ProviderName;
}
The Name is just the symbolic name you give your connection string - it can be anything, really.
The ConnectionString is the connection string itself.
The ProviderName is the name of the provider for the connection, e.g. System.Data.SqlClient for SQL Server (and others for other database system). If you omit the providerName= attribute from your connection string in config, it defaults to SQL Server (System.Data.SqlClient).
Marc

Use the connectionStrings section to define your connection strings.
<connectionStrings>
<add name="connection1" connectionString="user id=user;password=123;server=10.0.0.1;database=myDatabase;connection timeout=30"/>
<add name="connection2" connectionString="user id=user;password=123;server=10.0.0.2;database=myDatabase;connection timeout=30"/>
</connectionStrings>

Yes, it is possible to do this in another way. Check the connectionStrings section that you can make in the app.config file.
<configuration>
<connectionStrings>
<add name="" connectionString=""/>
<add name="" connectionString=""/>
</connectionStrings>
</configuration>

We can declare multiple connection string under Web.Config or App.Config
<connectionStrings>
<add name="SourceDB" connectionString="..." />
<add name="DestinationDB" connectionString="..." />
</connectionStrings>
In DAL or .cs file you can access connection strings like this string SounceConnection = ConfigurationManager.ConnectionStrings["SourceDB"].ConnectionString;
string DestinationConnection = ConfigurationManager.ConnectionStrings["DestinationDB"].ConnectionString;

You can use the AppSettings class, get a list of all keys that start with ConnectionString and display them.
Your config file will look like this:
<appSettings>
<add key="ConnectionString_Name1" value="..."/>
<add key="ConnectionString_Name2" value="..."/>
<add key="ConnectionString_Name3" value="..."/>
</appSettings>
You can get the name, by splitting the key name (using "_" in this example).
BTW: You should also use the ConnectionStrings section, you are only interrested in connection strings.

This is how to use LINQ to get list of connection strings:
List<string> connectionStrings = ConfigurationManager.ConnectionStrings
.Cast<ConnectionStringSettings>()
.Select(v => v.ConnectionString)
.ToList();
Or you can build a dictionary of it:
Dictionary<string/*name*/, string/*connectionString*/> keyValue = ConfigurationManager.ConnectionStrings
.Cast<ConnectionStringSettings>()
.ToDictionary(v => v.Name, v => v.ConnectionString);