c# - Connectionstring 没有从 dbconnection 传递到 dbfactory？

Question

我目前正在使用 dbfactory？用于访问我的数据库，但由于某种原因，连接字符串在从 dbconnection` 初始化时为空？

怎么会？

代码:

        var connect = System.Configuration.ConfigurationManager.ConnectionStrings["Db"];
        DbConnection db = new SqlConnection(connect.ConnectionString);
        Console.WriteLine("DbConnection: " + db.ConnectionString);
        DbProviderFactory factory = DbProviderFactories.GetFactory(db);
        System.Data.Common.DbConnection cn = factory.CreateConnection();
        Console.WriteLine("DbConnection from factory: " + cn.ConnectionString);
        Repository = new Repository();
        return Repository.Load(() => cn);

输出:

DbConnection: Server=<connetionstring>
DbConnection from factory:

Answer 1

试试下面的代码:

//get the information out of the configuration file.
var connectionStringSettings = 
       ConfigurationManager.ConnectionStrings["Db"];

//get the proper factory and mandatory to have SQL Provide name in the connection string
DbProviderFactory factory = 
  DbProviderFactories.GetFactory(connectionStringSettings.ProviderName);

//create a command of the proper type.
DbConnection conn = factory.CreateConnection();
//set the connection string
conn.ConnectionString = connectionStringSettings.ConnectionString;

//open the connection
conn.Open();

Repository = new Repository();
return Repository.Load(() => conn);