不支持DataBinding关键字：'metadata'

Question

有人可以帮我解决这个问题。我一直在努力解决这个错误几个小时，似乎无法解决这个问题。任何帮助将非常感激！

以下是我的WebConfig和后端代码。

<connectionStrings>
<add name="DB01Entities" connectionString="metadata=res://*/Model1.csdl|res://*/Model1.ssdl|res://*/Model1.msl;provider=System.Data.EntityClient;provider connection string=&quot;data source=(LocalDB)\MSSQLLocalDB;attachdbfilename=|DataDirectory|\DB01.mdf;integrated security=True;MultipleActiveResultSets=True;App=EntityFramework&quot;" providerName="System.Data.EntityClient" />
<connectionStrings/>

代码：

    protected void Page_Load(object sender, EventArgs e)
    {
        string CS = ConfigurationManager.ConnectionStrings["DB01Entities"].ConnectionString;
        using (SqlConnection con = new SqlConnection(CS))
        {
            SqlCommand cmd = new SqlCommand("Select Course_ID, Course_Institution, Course_Name, Course_Description, Course_CutOffPoints, Course_English, Course_Mathematics, Course_Science from tblCourse", con);
            con.Open();
            DropDownList1.DataSource = cmd.ExecuteReader();
            DropDownList1.DataTextField = "Course_Name";
            DropDownList1.DataValueField = "Course_ID";
            DropDownList1.DataBind();

        }
    }
}
}

错误消息的图片。 Error Message

再一次，非常感谢您的帮助！