There is already an open DataReader associated with this Connection which must be closed first.' code example

Example 1: There is already an open DataReader associated with this Command which must be closed first c#

<connectionStrings>
    <add name="IdentityConnection" connectionString="Data Source=(LocalDb)\v11.0;AttachDbFilename=|DataDirectory|\IdentityDb.mdf;Integrated Security=True;MultipleActiveResultSets=true;" providerName="System.Data.SqlClient" />
  </connectionStrings>

Example 2: c# datareader already open visual studio mysql

// Always, always, always put disposable objects inside of using statements:
using (Connection c = ...)
{
    using (DataReader dr = ...)
    {
        //Work with dr in here.
    }
}
//Now the connection and reader have been closed and disposed.

Example 3: There is already an open DataReader associated with this Connection which must be closed first.

there is already an open datareader associated with this command which must be closed.