var UserName = row["UserName"].ToString();
到
var UserName = reader["UserName"] != DBNull.Value ? row["UserName"].ToString():"";
更新
var UserName = "";
if(reader["UserName"] != DBNull.Value)
{
UserName = row["UserName"].ToString();
}
如何在C#中的datarow行中检查null
var UserName = row["UserName"].ToString();
到
var UserName = reader["UserName"] != DBNull.Value ? row["UserName"].ToString():"";
更新
var UserName = "";
if(reader["UserName"] != DBNull.Value)
{
UserName = row["UserName"].ToString();
}