parameterized top clause query in asp.net C#

Question

I want to use the top clause query in C#

objConnection = new SqlConnection(ConfigurationManager.AppSettings["connectionstring"].ToString());
            objConnection.Open();
            objCommand = new SqlCommand("SELECT TOP (@perpage) * FROM user_master", objConnection);
            objCommand.Parameters.AddWithValue("@perpage",objusmspass.strperpage);
            objReader = objCommand.ExecuteReader();

I am getting object reference not set to the instance of the object at line

objReader = objCommand.ExecuteReader();

Thanks,

Answer 1

检查您的自定义对象objusmspass及其属性是否为null，使用try catch块查看它是哪种异常（sqlException或其他异常）。