Enum List problem

scott_ill · 07-09-2009, 03:20 AM

Hi,

I'm trying to use .exists on list of enums but am getting the following error when trying to pass the value of the enumaerated constant:
"The best overloaded method match for 'System.Collections.Generic.List<TenderLib_v0._1.T enderOutcome>.Exists(System.Predicate<TenderLib_v0 ._1.TenderOutcome>)' has some invalid arguments"

Can someone pleas give me a pointer?

Code:

 
public enum TenderOutcome
    {
        Undetermined = 0,
        Won = 1,
        Lost = 2        
    }

internal void setOutcome(int o)
        {
List<TenderOutcome> valuesList= new List<TenderOutcome>();
            valuesList = this.OutcomeList; //OutcomeList just returns the values of type TenderOutcome from a dictionary
            foreach (TenderOutcome tender in valuesList)

            if (!(valuesList.Exists(TenderOutcome.Won)) || (valuesList.Exists(TenderOutcome.Lost)))
...........................
         }

Magos · 07-09-2009, 04:37 AM

Exists() expects a predicate (takes an enum, returns a bool). You pass the enum directly.
Use this instead:

Code:

.Exists(Value => (Value == TenderOutcome.Won))

However it's probably better to use the Contains method:

Code:

.Contains(TenderOutcome.Won)

scott_ill · 07-09-2009, 06:26 AM

Great stuff!

In the last hour I wrote an extra class to get .Exist to work like .Contains :/

Code:

public bool Check(List<TenderOutcome> outcomeList, int outcome)
        {
            if (OutcomeList.Exists(delegate(TenderOutcome x) { return x.Equals(outcome); }))
            { return true; }
            else return false;

        }

07-09-2009, 03:20 AM	#1
scott_ill Registered User Join Date: Jun 2009 Posts: 21	Enum List problem Hi, I'm trying to use .exists on list of enums but am getting the following error when trying to pass the value of the enumaerated constant: "The best overloaded method match for 'System.Collections.Generic.List<TenderLib_v0._1.T enderOutcome>.Exists(System.Predicate<TenderLib_v0 ._1.TenderOutcome>)' has some invalid arguments" Can someone pleas give me a pointer? Code: public enum TenderOutcome { Undetermined = 0, Won = 1, Lost = 2 } internal void setOutcome(int o) { List<TenderOutcome> valuesList= new List<TenderOutcome>(); valuesList = this.OutcomeList; //OutcomeList just returns the values of type TenderOutcome from a dictionary foreach (TenderOutcome tender in valuesList) if (!(valuesList.Exists(TenderOutcome.Won)) \|\| (valuesList.Exists(TenderOutcome.Lost))) ........................... }
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07-09-2009, 04:37 AM	#2
Magos Confused Join Date: Sep 2001 Location: Sweden Posts: 3,122	Exists() expects a predicate (takes an enum, returns a bool). You pass the enum directly. Use this instead: Code: .Exists(Value => (Value == TenderOutcome.Won)) However it's probably better to use the Contains method: Code: .Contains(TenderOutcome.Won) __________________ MagosX.com Give a man a fish and you feed him for a day. Teach a man to fish and you feed him for a lifetime.
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07-09-2009, 06:26 AM	#3
scott_ill Registered User Join Date: Jun 2009 Posts: 21	Great stuff! In the last hour I wrote an extra class to get .Exist to work like .Contains :/ Code: public bool Check(List<TenderOutcome> outcomeList, int outcome) { if (OutcomeList.Exists(delegate(TenderOutcome x) { return x.Equals(outcome); })) { return true; } else return false; }
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