必须声明标量变量 "@User_Name"。
public static DataTable Selectlist(string user_Name,string user_ID)
{
List<U_Userinfo> list = new List<U_Userinfo>();
string sql = "select * from U_USERINFO where User_Name = @User_Name or User_ID = @User_ID ";
SqlParameter[] par = new SqlParameter[] {
new SqlParameter("@User_Name",user_Name),
new SqlParameter("@User_ID",user_ID)
};
DataTable dt = DBHelper.ExcuteDataTable(sql, CommandType.Text, par);
return dt;
}