title: Removing the hard coded value to app.config file
body: <p>I have developed a form that takes from user the user id and password and display the list of databases available in the local server.Now I have done it in hard coded format...like this</p>
  
  <pre><code>public void BindDBDropDown()
  {
      //Create the connection object
      SqlConnection sConnection = new SqlConnection(
          ConfigurationSettings.AppSettings["ConnectionString"]);
  
      //To Open the connection.
      sConnection.Open();
  
      //Query to select the list of databases.
      string selectDatabaseNames =
          @"SELECT NAME FROM MASTER..SYSDATABASES";
  
      //Create the command object
      SqlCommand sCommand = 
          new SqlCommand(selectDatabaseNames, sConnection);
  
      try
      {
          //Create the data set 
          DataSet sDataset = new DataSet("master..sysdatabases");
  
          //Create the dataadapter object
          SqlDataAdapter sDataAdapter = 
              new SqlDataAdapter(selectDatabaseNames, sConnection);
          sDataAdapter.TableMappings.Add("Table", 
              "master..sysdatabases");
  
          //Fill the dataset
          sDataAdapter.Fill(sDataset);
  
          //Bind the database names in combobox
          DataViewManager dsv = sDataset.DefaultViewManager;
  
          //Provides the master mapping between the sourcr table 
          //and system.data.datatable
          cmbDatabases.DataSource = 
              sDataset.Tables["master..sysdatabases"];
          cmbDatabases.DisplayMember = "NAME";
          cmbDatabases.ValueMember = ("NAME");
      }
      catch(Exception ex)
      {
          //All the exceptions are handled and written in the EventLog.
          EventLog logException = new EventLog("Application");
          logException.Source = "MFDBAnalyser";
          logException.WriteEntry(ex.Message);
      }
      finally
      {
          //If connection is not closed then close the connection
          if(sConnection.State != ConnectionState.Closed)
          {
              sConnection.Close();
          }
      }
  }
  
  /// &lt;summary&gt;
  ///This function binds the names of all the tables with primary 
  ///keys in a dropdown cmbResults.
  /// &lt;/summary&gt;
  public void GetPrimaryKeyTable()
  {
      //An instance of the connection string is created to manage
      //the contents of the connection string.
      var sqlConnection = new SqlConnectionStringBuilder();
      sqlConnection.DataSource = "192.168.10.3";
      sqlConnection.UserID = "gp";
      sqlConnection.Password = "gp";
      sqlConnection.InitialCatalog = 
          Convert.ToString(cmbDatabases.SelectedValue);
      string connectionString = sqlConnection.ConnectionString;
  
      SqlConnection sConnection = new SqlConnection(connectionString);
  
      //To Open the connection.
      sConnection.Open();
  
      //Query to select the table_names that have PRIMARY_KEYS.
      string selectPrimaryKeys = @"
          SELECT  TABLE_NAME 
          FROM    INFORMATION_SCHEMA.TABLE_CONSTRAINTS 
          WHERE   CONSTRAINT_TYPE = 'PRIMARY KEY'
          AND     TABLE_NAME &lt;&gt; 'dtProperties'
          ORDER BY TABLE_NAME";
  
      //Create the command object
      SqlCommand sCommand = 
          new SqlCommand(selectPrimaryKeys, sConnection);
  
      try
      {
          //Create the dataset
          DataSet dsListOfPrimaryKeys = 
              new DataSet("INFORMATION_SCHEMA.TABLE_CONSTRAINTS");
  
          //Create the dataadapter object
          SqlDataAdapter sDataAdapter = 
              new SqlDataAdapter(selectPrimaryKeys, sConnection);
  
          //Provides the master mapping between the sourcr table 
          //and system.data.datatable
          sDataAdapter.TableMappings.Add("Table", 
              "INFORMATION_SCHEMA.TABLE_CONSTRAINTS");
  
          //Fill the dataset
          sDataAdapter.Fill(dsListOfPrimaryKeys);
  
          //Bind the result combobox with primary key tables
          DataViewManager dvmListOfPrimaryKeys = 
              dsListOfPrimaryKeys.DefaultViewManager;
          dgResultView.DataSource = dsListOfPrimaryKeys
              .Tables["INFORMATION_SCHEMA.TABLE_CONSTRAINTS"];
      }
      catch(Exception ex)
      {
          //All the exceptions are handled and written in the EventLog.
          EventLog log = new EventLog("Application");
          log.Source = "MFDBAnalyser";
          log.WriteEntry(ex.Message);
      }
      finally
      {
          //If connection is not closed then close the connection
          if(sConnection.State != ConnectionState.Closed)
          {
              sConnection.Dispose();
          }
      }
  }
  </code></pre>
  
  <p>Can anyone help me in removing these hardcoded things and taking the local server address, userid and password from the app.config file directly???</p>