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C# Creating a Func via reflection

I've got some code that's compiled at run time. Today it's using MethodInfo.Invoke. In an effort to speed things up I'm trying to create a delegate/func but I can't seem to find the correct overload/parameters to make it happen.
The current code is failing on the lambda compile with 'Incorrect number of parameters supplied for lambda declaration'
.Net v4.61
Any help would be appreciated.
// Contrived example code
public class MyItemClass
{
public bool IsDivisableBy3 { get; set; }
public bool IsEven { get; set; }
public MyItemClass(int value)
{
this.IsEven = value % 2 == 0;
this.IsDivisableBy3 = value % 3 == 0;
}
}
public class RuleTestResult
{
public int RuleNumber { get; set; }
public bool Result { get; set; }
}
private static var VbCode = #"Public NotInheritable Class RuleTest
Private Shared Function Rule1(item As MyItemClass) As Boolean
If item.IsEven Then
Return True
End If
End Function
Private Shared Function Rule2(item As MyItemClass) As Boolean
If item.IsEven = False Then
If item.IsDivisableBy3 Then
Return True
End If
End If
End Function
Public Shared Function FindRule(item As MyItemClass) As RuleTestResult
Select Case True
Case Rule1(item)
Return New RuleTestResult With {.RuleNumber = 1, .Result = True}
Case Rule2(item)
Return New RuleTestResult With {.RuleNumber = 2, .Result = True}
Case Else
Return New RuleTestResult With {.RuleNumber = -1, .Result = False}
End Select
End Function
End Class";
public static void TestMe()
{
// Make some test items
var Items = new List<MyItemClass>();
for (var i = 1; i <= 10; i++)
Items.Add(new MyItemClass(i));
// Compile the code
var CompilerResult = Compile(VbCode);
var Instance = CompilerResult.CompiledAssembly.CreateInstance("RuleTest");
var AssType = Instance.GetType();
var Method = Instance.GetType.GetMethod("FindRule");
var Param = Expressions.Expression.Parameter(Method.GetParameters.First.GetType);
// Create a func
Expressions.Expression CallExpression = Expressions.Expression.Call(Method, Param);
var MyFunc = Expressions.Expression.Lambda<Func<MyItemClass,RuleTestResult>>(CallExpression).Compile();
//'Incorrect number of parameters supplied for lambda declaration'
var Results = new List<RuleTestResult>();
foreach (var item in Items)
{
Results.Add(MyFunc(item))
}
}

I guess I just needed to post this to figure it out :)
var Param = Expressions.Expression.Parameter(typeof(RuleTest), "item");
var MyFunc = Expressions.Expression.Lambda<Func<MyItemClass,RuleTestResult>>(CallExpression**, Param**).Compile();

unit test case returning null while unit testing

I have a below method which simply unnest the list within list and and create merged record all sub lists
e.g.
testResultDTO similar to
{
dept_name :'',
dept_id:'',
personList :'<List>'
}
personList is list similat to
{
first_name :'',
Last_name:'',
workHistList:'<List>'
}
workHistList is similar to
{
task_name:'',
task_description:''}
`
And the method is below
public async Task<FileDTO> GetWorkList(InputParameter inputParameter)
{
TestResultDTO testResultDTO = await GetPersonWorkList(inputParameter);
var testDto = new List<TestDto>();
if (testResultDTO != null)
{
testDto = personWorkFile(testResultDTO);
}
return testDto;
}
The problem is in method personWorkFile
private List<testDTO> personWorkFile(testResultDTO testResultDTO)
{
List<testDTO> testDTO = new List<testDTO>();
if (testResultDTO.workList is null) return new();
foreach (var testItem in testResultDTO.workList)
{
if (testItem.personList != null && testItem.personList.Any())
{
for (var j = 0; j < testItem.personList.Count; j++)
{
List<testDTO> testDTOTemp = new List<testDTO>();
for (var i = 0; i < testItem.personList[j].workHistList.Count; i++)
{
testDTOTemp.Insert(i, mapper.Map(testItem.personList[j].workHistList[i], mapper.Map<testDTO>(testItem.personList[j])));
}
testDTO.AddRange(testDTOTemp);
}
}
}
return testDTO;
}
`
what it does is it create a finale list with record similar to
{dept_name,dept_id,first_name, last_name, task_name, task_description}
Now when i create a unit test for it, it always fail because, it always insert null in list testDTOTemp.insert
my content of test case code is below
mapperMock.Setup(m => m.Map<List<TestResultDTO>, List<TestDTO>>(testResultDTO)).Returns(testDTO);
//call actual service
var result = await workService.GetWorkList(inputParameter);
Can someone please help me understand why it is not able to insert any data testDTOTemp list

The mock replays the setup by matching the method arguments. In this particular case, it will try to match the method call with the specified instance of TestResultDTO.
Override the Equals() method in TestResultDTO to let the mock compare the argument in order to return as per the setup.
Ex:
public class TestResultDTO
{
public int Id {get; set;}
}
var dto01 = new TestResultDTO(){Id = 1};
var dto02 = new TestResultDTO(){Id = 1};
dto01.Equals(dto02); // This will result in false in spite of having same Ids
If the above class is modified to
public class TestResultDTO
{
public int Id {get; set;}
public override bool Equals(object other)
{
var right = other as TestResultDTO;
if(right == null) return false;
var left = this;
var result = left.Id == right.Id;
return result;
}
}
var dto01 = new TestResultDTO(){Id = 1};
var dto02 = new TestResultDTO(){Id = 1};
dto01.Equals(dto02); // This will result in true

Multiple tasks returns incorrect result

What I need to do
I need to start different instances of a class in a synchronous context using an async method.
Application structure
In my console application I've declared a List<Bot> class:
private List<Bot> _bots = new List<Bot>(new Bot[10]);
the class Bot contains some methods that takes data from internet, so these methods need to be waited. The method structure looks like this:
public class Bot
{
Competition Comp { get; set; }
public async Task StartAsync(int instance)
{
string url = "";
//based on the instance I take the data from different source.
switch(instance)
{
case 0:
url = "www.google.com";
break;
case 1:
url = "www.bing.com";
break;
}
//Comp property contains different groups.
Comp.Groups = await GetCompetitionAsync(Comp, url);
if(Comp.Groups.Count > 0)
{
foreach(var gp in group)
{
//add data inside database.
}
}
}
}
the Competition class have the following design:
public class Competition
{
public string Name { get; set; }
public List<string> Groups { get; set; }
}
I start all the instances of Bot class using the following code:
for(int i = 0; i < _bots.Count - 1; i++)
{
_bots[i].StartAsync(i);
}
this code will call different times StartAsync of Bot class, in this way, I can manage each instance of the bot, and I can eventually stop or start a specific instance in a separate method.
The problem
The method GetCompetitionAsync create a List<string>:
public async Task<List<string>> GetCompetitionAsync(Competition comp, string url)
{
if(comp == null)
comp = new Competition();
List<string> groups = new List<string();
using (var httpResonse = await httpClient.GetAsync(url))
{
string content = await httpResponse.Content.ReadAsStringAsync();
//fill list groups
}
return groups;
}
essentially this method will fill the List<string> available in Comp. Now, if I execute a single instance of StartAsync all works well, but when I run multiple instances (as the for above), the Comp object (which contains the Competition) have all the properties NULL.
So seems that when I have multiple Task running the synchronous context doesn't wait the async context, which in this case fill the List<string>.
When the code reach this line: if(Competition.Groups.Count > 0) I get a NULL exception, because Groups is null, and other Comp properties are NULL.
How can I manage this situation?
UPDATE
After other attempts, I though to create a List<Task> instead of a List<Bot>:
List<Task> tasks = new List<Task>(new Task[10]);
then instead of:
for(int i = 0; i < _bots.Count - 1; i++)
{
_bots[i].StartAsync(i);
}
I did:
for (int i = 0; i < tasks.Count - 1; i++)
{
Console.WriteLine("Starting " + i);
if (tasks[i] == null)
tasks[i] = new Task(async () => await new Bot().StartAsync(i));
apparently all is working well, I got no errors. The problem is: why? I though to something like a deadlock, that I can't even solve using ConfigureAwait(false);.
The last solution also doesn't allow me to access to Bot method because is now a Task.
UPDATE 2
Okay maybe I gotcha the issue. Essentially the await inside the asynchronous method StartAsync is trying to comeback on the main thread, meanwhile the main thread is busy waiting the task to complete, and this will create a deadlock.
That's why moving the StartAsync() inside a List<Task> has worked, 'cause now the async call is now running on a thread pool thread, it doesn't try to comeback to the main thread, and everything seems to works. But I can't use this solution for the reasons explained above.

I'm prefer use Threads instead of Tasks. IMHO, Threads more simple for understanding.
Note: seems that property Bot.Comp in your code is NOT initialized! I fix this issue.
My version of your code:
public class Bot
{
Competition Comp { get; set; }
System.Thread _thread;
private int _instance;
public Bot()
{
Comp = new Competition ();
}
public void Start(int instance)
{
_instance = instance;
_thread = new Thread(StartAsync);
_thread.Start();
}
private void StartAsync()
{
string url = "";
//based on the instance I take the data from different source.
switch(_instance)
{
case 0:
url = "www.google.com";
break;
case 1:
url = "www.bing.com";
break;
}
//Comp property contains different groups.
GetCompetitionAsync(Comp, url);
if(Comp.Groups.Count > 0)
{
foreach(var gp in group)
{
//add data inside database.
}
}
}
public List<string> GetCompetitionAsync(Competition comp, string url)
{
if(comp.groups == null) comp.groups = new List<string>();
using (var httpResonse = httpClient.GetAsync(url))
{
string content = await httpResponse.Content.ReadAsStringAsync();
//fill list groups
}
return groups;
}
}
Then we run threads:
for(int i = 0; i < _bots.Count - 1; i++)
{
_bots[i].Start(i);
}
Each instance of Bot starts method private void StartAsync() in it's own thread.
Note a implementation of method Bot.Start():
public void Start(int instance)
{
_instance = instance;
_thread = new Thread(StartAsync); //At this line: set method Bot.StartAsync as entry point for new thread.
_thread.Start();//At this line: call of _thread.Start() starts new thread and returns **immediately**.
}

This sort of thing is far simpler if you think in terms of lists and "pure" functions-- functions that accept input and return output. Don't pass in something for them to fill or mutate.
For example, this function accepts a string and returns the groups:
List<string> ExtractGroups(string content)
{
var list = new List<string>();
//Populate list
return list;
}
This function accepts a URL and returns its groups.
async Task<List<string>> GetCompetitionAsync(string url)
{
using (var httpResponse = await httpClient.GetAsync(url))
{
string content = await httpResponse.Content.ReadAsStringAsync();
return ExtractGroups(content);
}
}
And this function accepts a list of URLs and returns all of the groups as one list.
async Task<List<string>> GetAllGroups(string[] urls)
{
var tasks = urls.Select( u => GetCompetitionAsync(u) );
await Task.WhenAll(tasks);
return tasks.SelectMany( t => t.Result );
}
You can then stuff the data into the database as you had planned.
var groups = GetAllGroups( new string[] { "www.google.com", "www.bing.com" } );
foreach(var gp in groups)
{
//add data inside database.
}
See how much simpler it is when you break it down this way?

Await on item being present in a list

I'm currently looking for a way to monitor a list for an item to be added (although it may already be in the list) with a certain ID. The below example demonstrates what I want to do, however I was hoping there would be a neater approach to this.
var list = new List<string>();
var task = new Task<bool>(() =>
{
for (int i = 0; i < 10; i++)
{
if (list.Contains("Woft"))
return true;
Thread.Sleep(1000);
}
return false;
});
I would appreciate any suggestions, and can elaborate if required.
EDIT: I'm not sure how I would use a CollectionChanged handler for this, still not sure I'm describing the problem well enough, here is a more complete example.
class Program
{
private static List<string> receivedList = new List<string>();
static void Main(string[] args)
{
var thing = new item() { val = 1234, text = "Test" };
var message = new message() { id = "12", item = thing };
//This would be a message send
//in the receiver we would add the message id to the received list.
var task2 = new Task(() =>
{
Thread.Sleep(2000);
receivedList.Add(message.id);
});
task2.Start();
var result = EnsureReceived(thing, message.id);
if (result == null)
{
Console.WriteLine("Message not received!");
}
else
{
Console.WriteLine(result.text + " " + result.val);
}
Console.ReadLine();
}
//This checks if the message has been received
private static item EnsureReceived(item thing, string id)
{
var task = new Task<bool>(() =>
{
for (int i = 0; i < 10; i++)
{
if (receivedList.Contains(id))
return true;
Thread.Sleep(1000);
}
return false;
});
task.Start();
var result = task.Result;
return result ? thing : null;
}
}
class message
{
public string id { get; set; }
public item item { get; set; }
}
class item
{
public string text { get; set; }
public int val { get; set; }
}

It sounds like what you want to do is use an ObservableCollection and subscribe to the CollectionChanged event. That way, you'll have an event fire whenever the collection is modified. At that point, you can check if the collection has the element you're expecting.
Even better, the CollectionChanged event handler will receive NotifyCollectionChangedEventArgs, which contains a NewItems property.
See MSDN for more information.

You can implement own type, what intercept all operations to add items and exposes ReadOnlyList. Then create an event ItemAdded with added item value (you will have to rise up multiple events when adding a collection obviously). Subscribe to it, check, do whatever.

Variable not returning actual values

I want correctly return some variables (arrays)
kazkas.Ads[n]; (n = how many ads are)
kazkas.Ads[n].id;
kazkas.Ads[n].Days[m].Stats.Clicks; // every day have his own clicks
kazkas.Ads[n].Days[m].Stats.Impresons; // every day have his own impresions
from this method and use these variables in other class.
public static void GetAdsStats(string Ticket, DateTime start, DateTime end, int CamId)
{
var client = new CampaignStatsServiceClient();
var id = new CampaignIdFilter();
id.CampaignId = CamId;
var statsdata = new GetAdStatsData();
var kazkas = new Campaign();
kazkas = client.GetAdStats(Ticket, new GetAdStatsData
{
IdFilter = id,
StartDate = start,
EndDate = end
});
long AllClicks = 0;
long AllImpresions = 0;
int reklamos = kazkas.Ads.Length;
long[] statistikaClikai = new long[reklamos];
long[] statistikaImpresions = new long[reklamos];
for (int i = 0; i < reklamos; i++)
{
int dienos = kazkas.Ads[i].Days.Length;
for (int lop = 0; lop < dienos; lop++)
{
AllClicks = AllClicks + kazkas.Ads[i].Days[lop].Stats.Clicks;
AllImpresions = AllImpresions + kazkas.Ads[i].Days[lop].Stats.Impressions;
}
statistikaClikai[i] = AllClicks;
statistikaImpresions[i] = AllImpresions;
}
}
I know that void type can't return anything, but this how I know that my method works ( from debugging). Like you see I was trying do that with for loop. Here i have 9 Ads and every ad have one day.
Like I says I want return every Ads id[in array], and every days.stats.impresions and days.stats.click
how can I do that ? Ore how return more variables/arrays from method to other class, I am using webservises, so i cant use database ore something like that.

As can be seen by the downvotes of the question, you need to design the return value and then code against it.
Your query almost does it (now):
kazkas.Ads[n]; (n = how many ads are)
kazkas.Ads[n].id;
kazkas.Ads[n].Days[m].Stats.Clicks; // every day have his own clicks
kazkas.Ads[n].Days[m].Stats.Impressions; // every day have his own impressions
Your existing code show this should be expanded to include:
kazkas.Ads[n].Total.Clicks;
kazkas.Ads[n].Total.Impressions;
So now you're ready to design. First you want a Stat Class that just contains CLicks and Impressions:
public class Stat
{
public long Impressions { get; set; }
public long Clicks { get; set; }
}
An optimisation here may be to use a struct, but I won't go into that.
As you currently have defined it each Day has just a Stats property:
public class DayStat
{
public Stat Stats { get; set; }
}
Now finally we can define the top level AdStat:
public class AdStat
{
public int id { get; set; }
public DayStat Day[];
public Stat Total { get; set; }
}
Etc... There's further issues here, such as ensuring arrays are created and Stat instances are never null (which is why making some of these classes structs is an option). But I'm really a VB programmer so I'll stop here before I get caught typing crap into the SO IDE :-)

Create a class or struct with members you need
public class Stat
{
public int Id { get; set; }
public long Clicks { get; set; }
...
}
Change the signature of your method from void GetAdsStats to IEnumberable<Stat> GetAdsStats and either return a collection of stats or use yield keyword to return the stat object.
Also if you do not want your method to return anything (return type void) do not use a name starting with Get.
Example:
public static IEnumerable<Stat> GetAdsStats(...)
{
...
var statList = new List<Stat>();
for (int i = 0; i < reklamos; i++)
{
var stat = new Stat();
statList.Add(stat);
int dienos = kazkas.Ads[i].Days.Length;
for (int lop = 0; lop < dienos; lop++)
{
AllClicks = AllClicks + kazkas.Ads[i].Days[lop].Stats.Clicks;
AllImpresions = AllImpresions + kazkas.Ads[i].Days[lop].Stats.Impressions;
}
stat.Clicks = AllClicks;
stat.Impression = AllImpresions;
}
return statList;
}

Change your void to the type you want to return, say Campaign, and return the appropriate variable. The variables you define in your method, only live in your method and are not accessible from another method or class.