I've encountered the following issue while using protobuf-linq:
using (var stream = new MemoryStream())
{
SerializeMultiple(PrepareData(), stream);
}
private static void SerializeMultiple(IEnumerable<Person> persons, Stream stream)
{
foreach (var person in persons)
{
Serializer.Serialize(stream, person);
}
stream.Position = 0;
var q = RuntimeTypeModel.Default.AsQueryable<Person>(stream,null);
var results = from e in q
where e.Id % 2 == 0
select new { e.Id, e.Name };
Console.WriteLine("first : " + results.First().Id);
Console.ReadLine();
}
static IEnumerable<Person> PrepareData()
{
for (int i = 0; i < (int) 1e+04; i++)
{
yield return new Person {Id = i, Name= "John" + i, Address = "Address" + i*i};
}
}
[ProtoContract]
class Person
{
[ProtoMember(1)]
public int Id { get; set; }
[ProtoMember(2)]
public string Name { get; set; }
[ProtoMember(3)]
public string Address { get; set; }
}
The AsQueryable line throws the aforementioned exception:
Invalid field in source data: 0
Any thoughts on this matter?
It's not protobuf-linq error. When serializing items into a stream, you should use SerializeWithLengthPrefix to prefix every message with its length, to allow separate them. By default, protobuf-linq uses PrefixStyle.Base128. Below you can find a snippet making it right:
Serializer.SerializeWithLengthPrefix(stream, person, PrefixStyle.Base128);
Related
I have the following custom class
public class Album
{
public string PhotoName { get; set; }
public string Location { get; set; }
public DateTime DateTime { get; set; }
}
and I have the following string:
#"photo.jpg, Warsaw, 2013-09-05 14:08:15
john.png, London, 2015-06-20 15:13:22
myFriends.png, Warsaw, 2013-09-05 14:07:13
Eiffel.jpg, Paris, 2015-07-23 08:03:02
pisatower.jpg, Paris, 2015-07-22 23:59:59
BOB.jpg, London, 2015-08-05 00:02:03"
and I need to write a function that will append the order number beside the Location based on the timestamp thus the resulting StringBuilder must be
Warsaw01.jpg
London01.jpg
Warsaw02.jpg
Paris01.jpg
Paris02.jpg
London02.jpg
What I have done so far?
I have a List of that type that I sorted by Location then by DateTime
List<Album> SortedList = list
.OrderBy(o => o.Location)
.ThenBy(o => o.DateTime)
.ToList();
now I need to have a StringBuilder that will append the index number beside the location.
This is my complete method with the part and I am stuck on how should I search the ordered list. Question is: how can I write the LINQ for searching through the list?:
public static string Solution(string S)
{
string[] group = S.Split("\r\n");
List<Album> list = new List<Album>();
StringBuilder sb = new StringBuilder();
//added each line of the string to list
foreach (string g in group)
{
string[] album = g.Split(',');
Album a = new Album();
a.PhotoName = album[0];
a.Location = album[1];
a.DateTime = DateTime.Parse(album[2]);
list.Add(a);
}
//ordered the list
List<Album> SortedList = list.OrderBy(o => o.Location).ThenBy(o => o.DateTime).ToList();
//then foreach line, append index number by searching through the list
foreach (string g in group)
{
string[] album = g.Split(',');
Album a = new Album();
a.PhotoName = album[0];
string[] photodetails = a.PhotoName.Split('.');
a.Location = album[1];
a.DateTime = DateTime.Parse(album[2]);
//this is the part where I must figure out how to build the string. I am stuck here
// var query = SortedList.IndexOf(list.SingleOrDefault(i => i.DateTime == a.DateTime));
sb.AppendLine(a.Location + query + "." + photodetails[1]);
}
string res = sb.ToString();
return res;
}
Appreciate the responses.
Update Warsaw2 must appear before Warsaw1 since the timestamp of Warsaw2 is later than Warsaw1
Warsaw02.jpg
London01.jpg
Warsaw01.jpg
Paris01.jpg
Paris02.jpg
London02.jpg
I have just added a order in the Album class
public class Album
{
public string PhotoName { get; set; }
public string Location { get; set; }
public DateTime DateTime { get; set; }
public int Order { get; set; }
}
public static string Solution(string S)
{
string[] stringSeparators = new string[] { "\r\n" };
string[] group = S.Split(stringSeparators, StringSplitOptions.None);
List<Album> list = new List<Album>();
StringBuilder sb = new StringBuilder();
//added each line of the string to list
for (int i = 0; i < group.Length; i++)
{
string[] album = group[i].Split(',');
Album a = new Album();
a.PhotoName = album[0];
a.Location = album[1];
a.DateTime = DateTime.Parse(album[2]);
a.Order = i;
list.Add(a);
}
//ordered the list
var groupedByLocation = list.GroupBy(o => o.Location).ToList();
for (int i = 0; i < groupedByLocation.Count; i++)
{
int indexValue = 01;
foreach (var item in groupedByLocation[i])
{
item.PhotoName = string.Format("{0}{1}.jpg", groupedByLocation[i].Key, indexValue);
indexValue++;
}
}
//then foreach line, append index number by searching through the list
var locations = groupedByLocation
.SelectMany(g => g.Select(h => h))
.ToList()
.OrderBy(y => y.Order)
.Select(g => g.PhotoName);
return string.Join("\r\n", locations);
}
Just for the fun - an alternative approach:
For the task at hand, there's no need to have an Album class, a list and two loops.
We can go over the lines once, and use a dictionary to hold the counters for us.
class PhotoLocationsCounter
{
private readonly Dictionary<string, int> locationsCounter = new Dictionary<string, int>();
public string GetLocationsWithCounters(string source)
{
string[] lines = source.Split(new[] { '\n' }, StringSplitOptions.RemoveEmptyEntries);
var locations = lines.Select(this.LineToLocationWithCounter);
return string.Join("\n", locations);
}
private string LineToLocationWithCounter(string line)
{
string[] album = line.Split(',');
var location = album[1].Trim();
var ext = album[0].Split('.')[1];
var counter = this.GetAndIncreaseLocationCounter(location);
return $"{location}{counter.ToString("D2")}.{ext}";
}
private int GetAndIncreaseLocationCounter(string location)
{
if (!this.locationsCounter.TryGetValue(location, out int counter))
{
this.locationsCounter.Add(location, 0);
}
return ++this.locationsCounter[location];
}
}
And you call it:
string data = #"photo.jpg, Warsaw, 2013-09-05 14:08:15
john.png, London, 2015-06-20 15:13:22
myFriends.png, Warsaw, 2013-09-05 14:07:13
Eiffel.jpg, Paris, 2015-07-23 08:03:02
pisatower.jpg, Paris, 2015-07-22 23:59:59
BOB.jpg, London, 2015-08-05 00:02:03";
var locations = new PhotoLocationsCounter().GetLocationsWithCounters(data);
Lets say I have a list of asteroid objects like so:
9_Amphitrite
24_Themis
259_Aletheia
31_Euphrosyne
511_Davida
87_Sylvia
9_Metis
41_Daphne
Each asteroid has a title, a StartRoationPeriod, and a EndRoationPeriod.
I need to concatenate their names based on how close the current asteroid StartRoationPeriod and previous asteroid EndRoationPeriod are to an orbital constant and then spit out the concatenated title.
So with the above list, the final objects may look like this:
9_Amphitrite
24_Themis;259_Aletheia
31_Euphrosyne;511_Davida;87_Sylvia
9_Metis
41_Daphne
This requires me to keep track of both the current and previous asteroids.
I started to write the loop, but I'm unsure of where or even how to check the current asteroids start rotation period against the previous asteroids end rotation period...basically, it just gets messy fast...
string asteroid_title = string.Empty;
Asteroid prev_asteroid = null;
foreach (var asteroid in SolarSystem)
{
if (prev_asteroid != null)
{
if (asteroid.StartRoationPeriod + OrbitalConstant >= prev_asteroid.EndRoationPeriod)
{
asteroid_title = asteroid_title + asteroid.Title;
} else {
asteroid_title = asteroid.Title;
yield return CreateTitle();
}
}
prev_evt = evt;
}
I think this should work for you (If aggregate looks too complex try to convert it to a foreach,it's easy)
using System;
using System.Collections.Generic;
using System.Linq;
namespace Program
{
class Asteroid
{
public int EndRoationPeriod { get; internal set; }
public string Name { get; internal set; }
public int StartRoationPeriod { get; internal set; }
}
class AsteroidGroup
{
public int EndRoationPeriod { get; internal set; }
public string Names { get; internal set; }
}
internal class Program
{
private static void Main(string[] args)
{
int OrbitalConstant = 10;
List<Asteroid> SolarSystem = new List<Asteroid>()
{
new Asteroid() { Name= "9_Amphitrite" ,StartRoationPeriod=10 ,EndRoationPeriod=50},
new Asteroid() { Name= "24_Themis" ,StartRoationPeriod=45,EndRoationPeriod=100},
new Asteroid() { Name= "259_Aletheia",StartRoationPeriod=40 ,EndRoationPeriod=150},
new Asteroid() { Name= "31_Euphrosyne" ,StartRoationPeriod=60,EndRoationPeriod=200},
new Asteroid() { Name= "511_Davida" ,StartRoationPeriod=195,EndRoationPeriod=250},
new Asteroid() { Name= "87_Sylvia" ,StartRoationPeriod=90,EndRoationPeriod=300},
new Asteroid() { Name= "9_Metis" ,StartRoationPeriod=100,EndRoationPeriod=350},
new Asteroid() { Name= "41_Daphne" ,StartRoationPeriod=110,EndRoationPeriod=400},
};
var result = //I skip the first element because I initialize a new list with that element in the next step
SolarSystem.Skip(1)
//The first argument of Aggregate is a new List with your first element
.Aggregate(new List<AsteroidGroup>() { new AsteroidGroup { Names = SolarSystem[0].Name, EndRoationPeriod = SolarSystem[0].EndRoationPeriod } },
//foreach item in your list this method is called,l=your list and a=the current element
//the method must return a list
(l, a) =>
{
//Now this is your algorithm
//Should be easy to undrestand
var last = l.LastOrDefault();
if (a.StartRoationPeriod + OrbitalConstant >= last.EndRoationPeriod)
{
last.Names += " " + a.Name;
last.EndRoationPeriod = a.EndRoationPeriod;
}
else
l.Add(new AsteroidGroup { Names = a.Name, EndRoationPeriod = a.EndRoationPeriod });
//Return the updated list so it can be used in the next iteration
return l;
});
A more compact solution
var result = SolarSystem
.Skip(1)
.Aggregate( SolarSystem.Take(1).ToList(),
(l, a) => (a.StartRoationPeriod + OrbitalConstant >= l[l.Count - 1].EndRoationPeriod) ?
(l.Take(l.Count - 1)).Concat(new List<Asteroid> { new Asteroid() { Name = l[l.Count - 1].Name += " " + a.Name, EndRoationPeriod = a.EndRoationPeriod } }).ToList() :
l.Concat(new List<Asteroid> { a }).ToList()
);
I have the following code, I can figure why its invalid argument:
AuditDAL ad = new AuditDAL();
var agencies = ad.SearchAgencies("Ak001", "");
string col = param.sColumns.Split(',')[param.iSortCol_0];
string orderby = col + " " + param.sSortDir_0;
// The best overloaded method match for 'AMS.Helper.PaginatedList.PaginatedList(System.Linq.IQueryable, int, int)' has some invalid arguments C:\NexGen\AMS\DEV\Source\AMS\Controllers\AuditController.cs
var qry = new PaginatedList<AuditAgency>(agencies, param.iDisplayStart, param.iDisplayLength);
PaginatedList Code:
namespace AMS.Helper
{
public class PaginatedList<T> : List<T> {
public int PageIndex { get; private set; }
public int PageSize { get; private set; }
public int TotalCount { get; private set; }
public int TotalPages { get; private set; }
public PaginatedList(IQueryable<T> source, int pageIndex, int pageSize) {
PageIndex = pageIndex;
PageSize = pageSize;
TotalCount = source.Count();
TotalPages = (int) Math.Ceiling(TotalCount / (double)PageSize);
this.AddRange(source.Skip(PageIndex * PageSize).Take(PageSize));
}
public bool HasPreviousPage {
get {
return (PageIndex > 0);
}
}
public bool HasNextPage {
get {
return (PageIndex+1 < TotalPages);
}
}
}
}
Search Agencies Code:
public IEnumerable<AuditAgency> SearchAgencies(string ori, string name)
{
List<AuditAgency> agencies = new List<AuditAgency>();
using (var conn = new SqlConnection(_connectionString))
{
var com = new SqlCommand();
com.Connection = conn;
com.CommandType = CommandType.StoredProcedure;
string term = "Ori";
if (!String.IsNullOrEmpty(ori))
{
term = "Ori";
com.Parameters.Add(new SqlParameter
{
ParameterName = "#ORI",
Value = ori
});
}
if (!String.IsNullOrEmpty(name))
{
term = "legal_name";
com.Parameters.Add(new SqlParameter
{
ParameterName = "#Name",
Value = name
});
}
com.CommandText = "Audit_Get_Agency_List";
var adapt = new SqlDataAdapter();
adapt.SelectCommand = com;
var dataset = new DataSet();
adapt.Fill(dataset);
agencies = (from c in dataset.Tables[0].AsEnumerable()
select new AuditAgency()
{
Agency_ID = Convert.ToInt32(c["Agency_Id"]),
Agency_Name = c["Agency_Name"].ToString(),
Agency_Ori = c["ORI"].ToString(),
COPSAuditNumber = c["COPSAuditNumber"].ToString(),
OIGAuditNumber = c["OIGAuditNumber"].ToString()
}).ToList<AuditAgency>();
return agencies;
}
}
The error should tell you where to start.
If you fire up the debugger, I think you'll find agencies is an IEnumberable, but not an IQueryable
correct it by changing the return type of SearchAgencies from IQueryable to IEnumerable
or alternatively, you can change the type of the PaginatedList to accept IEnumberables instead of IQueryables. this may be safer as IQueryable inherits from IEnumerable
(see
http://msdn.microsoft.com/en-us/library/system.linq.iqueryable.aspx or
Differences between IQueryable, List, IEnumerator?
for the difference between the two)
we have a list of the class
public class DummyClass
{
public string Text { get; set; }
public int LevelNo { get; set; }
public List<DummyClass> Children { get; set; }
}
we want to add this list to another list with class.
public class FragmentLevel
{
public int currentLevelNo { get; set; }
public int ParentLevelNo { get; set; }
public string Text { get; set; }
}
we need the result like
var list = new List<FragmentLevel>
{
new FragmentLevel{ id = 1, text = "Root" },
new FragmentLevel{ id = 2, parent= 1, text = "Node-1.1" },
new FragmentLevel{ id = 3, parent= 2, text = "Node-1.1.1" }
};
For getting result we are doing like
for (int i = 0; i < DummyClassList.Count; i++)
{
list.Add(new FragmentLevel
{
currentLevelNo = DummyClassList[i].LevelNo,
Text = DummyClassList[i].Text,
});
do
{
for (int j = 0; j < DummyClassList[i].Children.Count; j++)
{
list1.Add(new FragmentLevel
{
LevelNo = DummyClassList[i].Children[j].LevelNo,
Text = DummyClassList[i].Children[j].Text,
});
}
} while (DummyClassList[i].Children[i].Children != null);
}
But this will give wrong result. How we can get the result?
Try this way of filling the fragments recursively,
private static void FillFragments(List<DummyClass> DummyClassList, List<FragmentLevel> list)
{
for (int i = 0; i < DummyClassList.Count; i++)
{
list.Add(new FragmentLevel
{
currentLevelNo = DummyClassList[i].LevelNo,
Text = DummyClassList[i].Text,
});
if (DummyClassList[i].Children != null && DummyClassList[i].Children.Count > 0)
{
FillFragments(DummyClassList[i].Children, list);
}
}
}
and the main method would look like this
static void Main(string[] args)
{
var DummyClassList = new List<DummyClass>
{
new DummyClass
{
Children = new List<DummyClass>
{
new DummyClass{
Children = null,
LevelNo=2,
Text = "two"
}
},
LevelNo = 1,
Text = "one"
}
};
var list = new List<FragmentLevel>();
FillFragments(DummyClassList, list);
}
I have a collection(people) that has a many-to-many reference to another collection(dogs). Suspend your disbelief on how there can be more than one people per dog. People just contains member which is an List<Dog>
I would like to select all the people where the people have a certain property(specified in an IList) and pets have a certain property(specified in an IList).
E.g. I have an IList (used for this query only) with the dog’s property value.
public enum EnumLikesToBite
{
No,
Yes,
Sometimes
}
IList <<EnumLikesToBite>> listDogsMayBite =
{ { EnumLikesToBite.Yes},
{ EnumLikesToBite.Sometimes}};
Then another list for the peoples property:
public enum EnumKeepsPetWith
{
Chain,
String,
Rubberband
}
IList <EnumKeepsPetWith> listPeopleWhoDontRestrainDog =
{ { EnumKeepsPetWith.String },
{ EnumKeepsPetWith.Rubberband}};
How can I query out all the people who have a dog that may bite and don’t restrain dog.
Like this pseudo code:
Var result = from p in People where p.KeepsPet in listPeopleWhoDontRestrainDog and dog.LikesToBite in listDogsMayBite.
Result has all the people. Of course if I could get all the dogs who may bite under those people that would be great.
List<int> mayBite = new List<int>()
{
(int) EnumLikesToBite.Yes,
(int) EnumLikesToBite.Maybe
}
List<int> poorRestraint = new List<int>()
{
(int) EnumKeepsPetWith.String,
(int) EnumKeepsPetWith.RubberBand
}
IQueryable<Person> query =
from p in db.People
where poorRestraint.Contains(p.KeepsPetWith)
where p.DogPeople.Any(dp => mayBite.Contains(dp.Dog.DoesBite))
select p;
var query =
from p in db.People
where poorRestraint.Contains(p.KeepsPetWith)
let bitingDogs =
from dp in p.DogPeople
let d = dp.Dog
where mayBite.Contains(d.DoesBite)
where bitingDogs.Any()
select new {Person = p, BitingDogs = bitingDogs.ToList()};
Maybe this code will help.. One of the possible solution are:
var result =
peoples.Where(y => dontRestrainDog.Contains(y.KeepsPetWith) && y.Dogs.Any(x => dogsMayBite.Contains(x.LikesToBite))).ToList();
result.ForEach(y => y.Dogs = y.Dogs.Where(x => dogsMayBite.Contains(x.LikesToBite)).ToList());
which you can see an example of here:
class Program
{
static void Main(string[] args)
{
IList<EnumLikesToBite> dogsMayBite = new List<EnumLikesToBite>
{
{ EnumLikesToBite.Yes }, { EnumLikesToBite.Sometimes }
};
IList<EnumKeepsPetWith> dontRestrainDog = new List<EnumKeepsPetWith>
{
{ EnumKeepsPetWith.String }, { EnumKeepsPetWith.Rubberband }
};
var peoples = new List<People>();
var dogs = new List<Dog>();
Random gen = new Random(2);
for(int i = 0; i < 10; i++)
{
People p = new People
{
PeopleId = i,
KeepsPetWith = (EnumKeepsPetWith) (gen.Next(10)%3),
Dogs = new List<Dog>()
};
Dog d = new Dog
{
DogId = i,
LikesToBite = (EnumLikesToBite) (gen.Next(10)%3),
Peoples = new List<People>()
};
peoples.Add(p);
dogs.Add(d);
}
for(int i = 0; i < 10; i++)
{
for(int j = 0; j < 10; j++)
{
if (gen.Next(10)>7)
{
peoples[i].Dogs.Add(dogs[j]);
}
if (gen.Next(10)>7)
{
dogs[i].Peoples.Add(peoples[j]);
}
}
}
PrintDogs(dogs);
PrintPeoples(peoples);
var result =
peoples.Where(y => dontRestrainDog.Contains(y.KeepsPetWith) && y.Dogs.Any(x => dogsMayBite.Contains(x.LikesToBite))).ToList();
result.ForEach(y => y.Dogs = y.Dogs.Where(x => dogsMayBite.Contains(x.LikesToBite)).ToList());
Console.WriteLine("===================");
PrintPeoples(result);
Console.ReadLine();
}
private static void PrintPeoples(List<People> peoples)
{
Console.WriteLine("=Peoples=");
foreach (var people in peoples)
{
Console.WriteLine("Id: {0}", people.PeopleId);
Console.WriteLine("KeepsPetWith: {0}", people.KeepsPetWith);
Console.WriteLine("Dogs: ");
foreach (var dog in people.Dogs)
{
Console.Write("{0}, ", dog.DogId);
}
Console.WriteLine();
}
}
private static void PrintDogs(List<Dog> dogs)
{
Console.WriteLine("=Dogs=");
foreach (var dog in dogs)
{
Console.WriteLine("Id: {0}", dog.DogId);
Console.WriteLine("LikesToBite: {0}", dog.LikesToBite);
Console.WriteLine("Peoples: ");
foreach (var people in dog.Peoples)
{
Console.Write("{0}, ", people.PeopleId);
}
Console.WriteLine();
}
}
}
public class People
{
public int PeopleId { get; set; }
public EnumKeepsPetWith KeepsPetWith { get; set; }
public IList<Dog> Dogs { get; set; }
}
public class Dog
{
public int DogId { get; set; }
public EnumLikesToBite LikesToBite { get; set; }
public IList<People> Peoples { get; set; }
}
public enum EnumLikesToBite
{
No,
Yes,
Sometimes
}
public enum EnumKeepsPetWith
{
Chain,
String,
Rubberband
}