Get connection string from app.config file

Get connection string from app.config file

• Marc van de Wert

  I have sorted out at least some of the problem. If you let VS create your connection string in app.config, it's a multi-node name. Be sure to use the entire name in your reference thus:
  

  private static string conStr = ConfigurationManager.ConnectionStrings["DALforDaily.Properties.Settings.DSNT"].ConnectionString;
  
  Also note that the string must be static, or when you use it to instantiate the Db connection, the compiler complains. At this point, I am getting the desired value into the string - but so far, trying to use it is not working. I get a message that I have an "invalid argument", not terribly informative...

   

  
  

• Atheist

  I am using the connection string and it works excelent for me.
  
  Its very simple :)
  
  you can Import the Connection string which resides in Project Settings.
  
  

  string str= Properties.Settings.Default.myConnectionString;

  
  
  let me past all of my code for LoaddataBase() function so it can  explain how can one use the DataTable also. This is enhanced version of the older DataTable object.
  
  I am populating  Listbox from my the Table object below.
  

  private void LoadDataBase(){        this._TreeView.Nodes.Add("Tasks"); try{        DataTable myTable = new DataTable("myTable"); using (OleDbConnection conn = new OleDbConnection(Properties.Settings.Default.myConnectionString)){       conn.Open();      OleDbCommand cmd = new OleDbCommand                                    (@"SELECT Tasks.FullTaskName   FROM Tasks", conn);     OleDbDataReader rd = cmd.ExecuteReader();     myTable.Load(rd);      //this was only possible with DataSet object earlier ----Cool eh ;) foreach (DataRow row in myTable.Rows){ TreeNode node = new TreeNode(row[0].ToString()); this._TreeView.Nodes[0].Nodes.Add(node); this._TreeView.Sorted = true; } conn.Close(); } } catch (OleDbException e){ MessageBox.Show("Error: {0}" + e.Errors[0].Message); } }

  
  
  
  Did it help mark it!

  
  
  

• Jeffrey E. Moeller

  Hmm,
  
  thats strange how can a propety be obsolete, if its new in .net 2.0.
  
  

  Note: This property is new in the .NET Framework version 2.0. from MSDN

  
  
  Has anyone from MS an idea
  
  But it works, I woud ignore the message and use it until you know further details.
  
  

• araus

  This code did not work for me, it does not return a string. Here's what worked for me with vs 2005/.net 2.0:
  
  string str = ConfigurationManager.ConnectionStrings["theConnStrName"].ConnectionString;
  
  where "theConnStrName" is from app.config file:
  
  <connectionStrings>
  <add name="theConnStrName" etc...

  
  

• Dan Scott

  AppSettings is obsolete. ClientSettingsSection is the new way (for Windows Forms client applications).

  I have a problem with my code. I am trying to save a value to the client settings area.

  ClientSettingsSection css = new ClientSettingsSection();

  css.Settings.Get(edURL.Name).Value = edURL.Text;

  Error 1 Cannot implicitly convert type 'string' to 'System.Configuration.SettingValueElement'

  I need an example of how to do it right

  
  

• Rufus Littlefield - MSFT

  It's still not working for me... CondigurationManager is not even recognized as a class although i have added

  using System.Configuration; line
  
  I get "ConfigurationManager does not exist in the current context message"
  
  why is that
  
  this is the code i want to work:
  
  

  using System;< xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />

  using System.Collections.Generic;

  using System.Text;

  using System.Configuration;

  using System.Data.SqlClient;

  using System.IO;

   

  namespace myMoney

  {

   

      class DB

      {

          const string connectionSting = ConfigurationManager.ConnectionStrings["myMoney.Properties.Settings.myMoneyConnectionString"].ConnectionString;

         

          public static string GetSingleValue(string queryString)

          {

              object queryResult;

   

              using (SqlConnection connection = new SqlConnection(

                         connectionSting))

              {

                  SqlCommand command = new SqlCommand(queryString);

                  command.Connection = connection;

                  connection.Open();

   

                  queryResult = command.ExecuteScalar();

                  connection.Close();

                  return queryResult.ToString();

              }

          }

   

          public static void WriteSingleValue(string updateString)

          {

              using (SqlConnection connection = new SqlConnection(connectionSting))

              {

                  SqlCommand command = new SqlCommand(updateString);

                  command.Connection = connection;

                  connection.Open();

                  command.ExecuteNonQuery();

                  connection.Close();

              }

          }

      }

  }

   

   

  
  

  
  
  

• Hancz

  Hi,
  
  Can you be more specific when you say, the ConfigurationManager wont work
  
  The code snippet below shows the usage of the ConfigurationManager class:
  
  

  string strConnectionString=ConfigurationManager.AppSettings["ConnectionString"];

  
  
  Note that you will need to add a Reference explicitly to the System.Configuration.DLL assembly for the ConfigurationManager and add a using directive for System.Configuration for the class to be available to you.
  
  Regards,
  Vikram
  
  

• damonbaker

  I am having the exact same problem with getting any appSetting from the config file.  The code completion only supports the dotnet 1.x objects but the compiler fails on the with errors requiring dotnet 2.0 objects.  This is a fresh install of 2.0.  Wonder if there is a dependency on 1.x runtime for this code to compile, or VS is just flaky.  I can post a bunch of sample code, but it is all using unsupported interfaces on a clean VS 2005 install since the 2.0 interfaces do not compile.  Help MS!
  
  
  

• mikejliddell

  Sorry my bad english. English is not my native language.
  On VS 2005 you access app.config this way:
  

           dim the_name_of_the_thing as string = "este_parametro"
           dim the_value_of_the_thing as string = ""
           the_value_of_the_thing = My.Settings.Item(the_name_of_the_thing)

  On app.config you can see a section like this:
  

           <setting name="este_parametro" serializeAs="String">
           <value>15</value>
           </setting>

  That's all you have to do.
  
  
  

• Jason Brower

  I need this thing on C#/.NET 2.0 not vb
  
  

• Jorge MVP

  Article suggests to use
  
  ConfigurationSettings.AppSettings["ConnectionString"];
  
  in order to get connection string, but compiler says "This method is obsolete, it has been replaced by ConfigurationManager.AppSettings"
  
  I tried this manager but ir won't work either... :(
  
  anyone can suggest anything else

  
  
  

• Paulustrious

  What I had to do to get mine to work in VS2005.
  
  Just declaring the System.Configuration is not enough. I had to Add Reference>System.Configuration.DLL after that the error "ConfigurationMananger is not declared" went away.
  
  

  Imports System

  Imports System.IO

  Imports System.Configuration

  Module FileCleanup

  Dim FileName As String

  Dim FilePath As String = ConfigurationManager.AppSettings("FilePath")

  
  

• Sugoiram

  Hi,
  
  look at this code on how to get information from a aapplication.config file.
  
  They show it with a title and a connection string.
  
  http://www.codeguru.com/columns/DotNet/article.php/c7987/
  
  

• Ben Herron

  1.

  ConfigurationManager.ConnectionStrings["AppName.Properties.Settings.ConnStr"].ConnectionString

  2.

  object value = Properties.Settings.Default.<xxx>

  Thank you !!!

  Search Keys: configSections, sectionGroup, applicationSettings, setting, name, serializeAs, connectionStrings, providerName, System.Data.SqlClient

  
  
• Get connection string from app.config file