问如何使用实体框架设置连接字符串

EN

public string CreateConnectionString(string BasicConnectionString)
{
    //EntityConnectionFactory 
    var entityConnectionStringBuilder= new EntityConnectionStringBuilder();
    entityConnectionStringBuilder.Provider = "Your Provicer here"      //For me it is "System.Data.SqlClient";
    entityConnectionStringBuilder.ProviderConnectionString = BasicConnectionString;
    entityConnectionStringBuilder.Metadata = "res://*";
    return entityConnectionStringBuilder.ToString();
}

MyContext ctx = new MyContext(CreateConnectionString())

public partial class DataContext : ObjectContext
    {
        #region Constructors

        /// <summary>
        /// Initializes a new DataContext object using the connection string found in the 'DataContext' section of the application configuration file.
        /// </summary>
        public DataContext() : base("name=DataContext", "DataContext")
        {
            this.ContextOptions.LazyLoadingEnabled = true;
            OnContextCreated();
        }

        /// <summary>
        /// Initialize a new DataContext object.
        /// </summary>
        public DataContext(string connectionString) : base(connectionString, "DataContext")
        {
            this.ContextOptions.LazyLoadingEnabled = true;
            OnContextCreated();
        }

        /// <summary>
        /// Initialize a new DataContext object.
        /// </summary>
        public DataContext(EntityConnection connection) : base(connection, "DataContext")
        {
            this.ContextOptions.LazyLoadingEnabled = true;
            OnContextCreated();
        }

        #endregion

        #region Partial Methods

        partial void OnContextCreated();

        #endregion
    ...
    }

public partial class WMSChennaiDEVEntities : DbContext
{
    public WMSChennaiDEVEntities(string connectionstring)
            : base(connectionstring)
    {
    }
}

    <connectionStrings>

<add name="Connection1" connectionString="Server=localhost\ServerInstance;Database=MyDB;Trusted_Connection=True;" providerName="System.Data.SqlClient" />

    public class MyContext : DbContext
{
    public MyContext():base("Connection1")
    {...}