Question

这里我在抽象类

中使用连接状态

  public abstract class Connection
    {
        private static string _Connection = ConfigurationManager.ConnectionStrings["CTXDB"].ConnectionString;
 public static string GetConnection{ get { return _Connection; }}
}
    public abstract void ProcessConnection();

这个类我在另一个类（BusinessConnection.cs）中实现

 public class BusinessClass :Connection
    {
     public override void ProcessConnection()
            {
                using (var conn = new SqlConnection(Connection.GetConnection))
                {
                    conn.Open();
                }
            }

现在我在我的控制器中调用了这个类（BusinessConnection.cs）

     BusinessClass objcon = new BusinessClass();   
  public IHttpActionResult Index()
                    objcon.ProcessConnection();
                    SqlCommand cmd = new SqlCommand("select * from Employee");
//Here how can i inject my Connection in cmd
                    SqlDataReader rdr = cmd.ExecuteReader();
                    if (rdr.HasRows == true)

Answer 1

似乎有一点点设计缺陷。您显然希望使用BusinessClass / Connection类之外的连接。

所以也许你可以这样做：

public abstract class Connection
{
    public abstract SqlConnection OpenConnection();

    // your code
}

和您的BusinessClass：

public override SqlConnection OpenConnection()
{
     var conn = new SqlConnection(Connection.GetConnection))
     conn.Open();
     return conn;
}

然后在你的查询代码中：

using(SqlConnection conn = objcon.OpenConnection())
{
    // create SqlCommand and pass conn!
    using(SqlCommand cmd = new SqlCommand("select * from Employee", conn))
    {
        using (SqlDataReader rdr = cmd.ExecuteReader())
        {
        // and the rest of your rdr reading code
        }
    }
}

using语句负责关闭/处理相应的对象。

ExecuteReader：尚未初始化Connection属性。而我正在使用抽象类连接

1 个答案: