Question

connection属性尚未初始化

private static SqlConnection conn;
public static SqlConnection Conn
{
get
{
string connString = ConfigurationManager.ConnectionStrings["connStr"].ConnectionString;
//string connString = "server=.;database=SportShop;uid=hao;pwd=123456";
if (conn == null)
{
conn = new SqlConnection(connString);
conn.Open();
}
else if (conn.State == System.Data.ConnectionState.Closed)
{
conn.Open();
}
else if (conn.State == System.Data.ConnectionState.Broken)
{
conn.Close();
conn.Open();
}
return conn;
}
}

//执行一条带参数的Sql查询语句，查询结果以SqlDataReader的形式返回
public static SqlDataReader GetReader(string sql, params SqlParameter[] values)
{
SqlCommand cmd = new SqlCommand(sql,conn);
//cmd.Connection = conn;
cmd.Parameters.AddRange(values);
SqlDataReader reader = cmd.ExecuteReader( );
return reader;
}
}
connection属性尚未初始化

Answer 1

SqlCommand cmd = new SqlCommand(sql,conn);
改为：
SqlCommand cmd = new SqlCommand(sql,Conn);
//注意：你的Conn才是属性，小写的conn是字段，只是一个对象，没有实例化~~所以报错~~