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Thread: connection string config help

  1. #1
    Join Date
    May 2016

    Post connection string config help

    ive recently learnt that you can store connection strings in a .config file so i created one (connectionstring) for to test this out however whenever i run this i get a object reference not set to an instance of an object ive referenced system.configuration.dll and im using system.configuration; but i cant figure out why this is throwing this error

    using System;
    using System.Configuration;
    using System.Data;
    using System.Data.SqlClient;
    using System.Windows;
    using System.Windows.Input;
    using System.Windows.Threading;
    namespace ExperimentingApplication
        /// <summary>
        /// Interaction logic for AuthenticationScreen.xaml
        /// </summary>
        public partial class AuthenticationScreen : Window
           public AuthenticationScreen()
            private void UserInputKeyDown(object sender, KeyEventArgs e)
                if (e.Key == Key.Enter) //only accepts enter key
                    string dbconnection = ConfigurationManager.ConnectionStrings["Database"].ConnectionString;  //if there is anyway of condensing it please let me know
                    SqlConnection connection = new SqlConnection(dbconnection);
                    if (connection.State == ConnectionState.Open) // if connection.Open was successful
                        MessageBox.Show("You have been successfully connected to the database!");
                        MessageBox.Show("Connection failed.");
    this is the connectionstring.config file

    <?xml version="1.0" encoding="utf-8" ?>
        <add name="Database" connectionString="Server=******-*******;Database=TestDatabse;Trusted_Connection=True;" providerName="System.Data.SqlClient" />

  2. #2
    Join Date
    May 2016

    Re: connection string config help

    im also using .net 4.6.1

  3. #3
    Arjay's Avatar
    Arjay is offline Moderator / EX MS MVP Power Poster
    Join Date
    Aug 2004

    Re: connection string config help

    You need to add a config file to your project and put the connectionstrings section in there. To do this, click add new item and choose config file.

    This will add an app.config file to your project and when you compile the project, it will automatically generate an myprojectname.exe.config file in the output folder.

    It isn't working for you because you have a connectionstring.config file which the program knows nothing about.

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