title: Connection string in app.config
body: <p>how to add this C# code connection string in app.config file for windows forms application program ?
  i see examples of adding access db but i need to add excel file data , so can't find previous question on excel file connection in app.config.</p>
  
  <pre><code>OleDbConnection conn = new OleDbConnection();
  conn.ConnectionString = @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=D:\MISD_report.xlsx" + @";Extended Properties=""Excel 12.0 Xml;HDR=YES;IMEX=1;ImportMixedTypes=Text;TypeGuessRows=0""";
  </code></pre>