Returns the last element of a sequence, or a default value if the sequence contains no elements. Enumerates and transforms a sequence, and produces an immutable sorted dictionary of its contents. All rights reserved. (this book is amazing, you must get it if you have to buy but one C# rev2023.6.29.43520. Returns a collection of the child nodes of every document and element in the source collection. The index of each source element is used in the intermediate projected form of that element. When an object is cast to a base class, how does it remember what it really is? I want to limit the amount of data shown in a page coming from a database. You have to create a List first and add your object to that list, as, And then you can assign your list to the enumerable, as. Returns a collection of the child elements of every element and document in the source collection. :-). Constructs an immutable dictionary from an existing collection of elements, applying a transformation function to the source keys. Returns a collection of the descendant nodes of every document and element in the source collection. atRiskGroup.PlacesToPlay.Add(newFunplace("Disneyland")); atRiskGroup.PlacesToPlay.Add(newFunplace("SixFlags")); atRiskGroup.PlacesToPlay.Add(newFunplace("SearsRacepoint")); //Thisassummesthatifyouknowyouarelookingforthepropertyname"Workplaces". as operator only perform a cast and return null if the cast fails. //SinceyouwantyourSingleEntitiestohavedataaccess,showthattheydo. #. Applies an accumulator function over a sequence. @Aniket - There is quite definitely a point. c# - Dynamically casting to IEnumerable<T> or T - Stack Overflow Determines whether a sequence contains any elements. Invokes a transform function on each element of a sequence and returns the minimum nullable Int64 value. The Conversion operators in LINQ are useful in converting the type of the elements in a sequence (collection). Returns a DataTable that contains copies of the DataRow objects, given an input IEnumerable object where the generic parameter T is DataRow. Methods GetEnumerator() . For the non-generic version of this interface, see System.Collections.IEnumerable. Creates a HashSet from an IEnumerable using the comparer to compare keys. Computes the sum of the sequence of Int32 values that are obtained by invoking a transform function on each element of the input sequence. publicabstractNewPluralEntityGetListOfPlaces(); publicabstractICollectionGetListOfDBItems(); publicWorkplace(stringname){this.s=name;}, publicstringCompany{get{returnthis.s;}}, publicvoidWriteToDB(){Console.WriteLine("WroteWorkplace{0}toDB. By voting up you can indicate which examples are most useful and appropriate. I am new to vb .net, How to cast an IEnumerable<object> to an IEnumerable<runtime type> hello, Is there code or static lib for hook swapchain present? Can one be Catholic while believing in the past Catholic Church, but not the present? It could be an array, a List, or whatever. It's just a funny case of "surprising, yet obvious". Computes the sum of the sequence of nullable Int64 values that are obtained by invoking a transform function on each element of the input sequence. c# - Cast object to IEnumerable - Stack Overflow - Where Developers Making statements based on opinion; back them up with references or personal experience. a. no other change b. compiler infers IEnumerable<TResult!> if input is IEnumerable<TSource!> (despite what the API says) return TResult! Creates a Dictionary from an IEnumerable according to a specified key selector function, a comparer, and an element selector function. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. The as operator explicitly converts an expression to a given type if its run-time type is compatible with that type. The immediate return value is an object that stores all the information that is required to perform the action. Computes the average of a sequence of nullable Int64 values that are obtained by invoking a transform function on each element of the input sequence. Computes the average of a sequence of nullable Single values that are obtained by invoking a transform function on each element of the input sequence. Let's go by an example. Or maybe call .ToList() on the destination type and use that as the destination instead of using a cast? 1. [Solved]-How to cast an IEnumerable<object> to an IEnumerable<runtime and later i want to retrieve each ArrayList items and type cast to the IEqualityComparer), Last(IEnumerable, Func), LastOrDefault(IEnumerable), LastOrDefault(IEnumerable, TSource), LastOrDefault(IEnumerable, Func), LastOrDefault(IEnumerable, Func, TSource), LongCount(IEnumerable, Func), Max(IEnumerable, IComparer), Max(IEnumerable, Func), Max(IEnumerable, Func), Max(IEnumerable, Func), Max(IEnumerable, Func), Max(IEnumerable, Func>), Max(IEnumerable, Func>), Max(IEnumerable, Func>), Max(IEnumerable, Func>), Max(IEnumerable, Func>), Max(IEnumerable, Func), Max(IEnumerable, Func), MaxBy(IEnumerable, Func), MaxBy(IEnumerable, Func, IComparer), Min(IEnumerable, IComparer), Min(IEnumerable, Func), Min(IEnumerable, Func), Min(IEnumerable, Func), Min(IEnumerable, Func), Min(IEnumerable, Func>), Min(IEnumerable, Func>), Min(IEnumerable, Func>), Min(IEnumerable, Func>), Min(IEnumerable, Func>), Min(IEnumerable, Func), Min(IEnumerable, Func), MinBy(IEnumerable, Func), MinBy(IEnumerable, Func, IComparer), OrderBy(IEnumerable, Func), OrderBy(IEnumerable, Func, IComparer), OrderByDescending(IEnumerable, Func), OrderByDescending(IEnumerable, Func, IComparer), OrderDescending(IEnumerable, IComparer), Prepend(IEnumerable, TSource), Select(IEnumerable, Func), Select(IEnumerable, Func), SelectMany(IEnumerable, Func>), SelectMany(IEnumerable, Func>), SelectMany(IEnumerable, Func>, Func), SelectMany(IEnumerable, Func>, Func), SequenceEqual(IEnumerable, IEnumerable), SequenceEqual(IEnumerable, IEnumerable, IEqualityComparer), Single(IEnumerable, Func), SingleOrDefault(IEnumerable), SingleOrDefault(IEnumerable, TSource), SingleOrDefault(IEnumerable, Func), SingleOrDefault(IEnumerable, Func, TSource), Skip(IEnumerable, Int32), SkipLast(IEnumerable, Int32), SkipWhile(IEnumerable, Func), SkipWhile(IEnumerable, Func), Sum(IEnumerable, Func), Sum(IEnumerable, Func), Sum(IEnumerable, Func), Sum(IEnumerable, Func), Sum(IEnumerable, Func>), Sum(IEnumerable, Func>), Sum(IEnumerable, Func>), Sum(IEnumerable, Func>), Sum(IEnumerable, Func>), Sum(IEnumerable, Func), Take(IEnumerable, Int32), Take(IEnumerable, Range), TakeLast(IEnumerable, Int32), TakeWhile(IEnumerable, Func), TakeWhile(IEnumerable, Func), ToDictionary(IEnumerable, Func), ToDictionary(IEnumerable, Func, IEqualityComparer), ToDictionary(IEnumerable, Func, Func), ToDictionary(IEnumerable, Func, Func, IEqualityComparer), ToHashSet(IEnumerable, IEqualityComparer), ToLookup(IEnumerable, Func), ToLookup(IEnumerable, Func, IEqualityComparer), ToLookup(IEnumerable, Func, Func), ToLookup(IEnumerable, Func, Func, IEqualityComparer), TryGetNonEnumeratedCount(IEnumerable, Int32), Union(IEnumerable, IEnumerable), Union(IEnumerable, IEnumerable, IEqualityComparer), UnionBy(IEnumerable, IEnumerable, Func), UnionBy(IEnumerable, IEnumerable, Func, IEqualityComparer), Where(IEnumerable, Func), Where(IEnumerable, Func), Zip(IEnumerable, IEnumerable), Zip(IEnumerable, IEnumerable, IEnumerable), Zip(IEnumerable, IEnumerable, Func), AsParallel(IEnumerable), AsQueryable(IEnumerable), Walkthrough: Implementing IEnumerable(Of T) in Visual Basic. In general that would be a bad practice. How to deploy AntDB Community Version on a virtual machine on VMware WorkstationP3, How to send live message and notification to all the Access Database frontend users, The next Access Europe meeting is on Wed 5 July - Interactive Gantt Chart Scheduler in Access, publicabstractclassNewPluralEntity:ICollection,IEnumerable, publicclassWorkplaces:NewPluralEntity, publicArrayListGetNewPluralEntityPropertyUsingReflection(stringp_propertyName). Use of "Enumerable.Cast" and "Enumerable.OfType" in C# - TechNet The type to cast the elements of source to. For instance, an IEnumerable<int> is assigned to BaseDataList.DataSource, BaseDataList.DataSource is an Object type, I want to get its real type and iterate it, I don't know how to implement. Returns the element at a specified index in a sequence or a default value if the index is out of range. The default equality comparer is used to compare keys. The default equality comparer is used to compare keys. Cast object to IEnumerable Ask Question Asked 9 years, 1 month ago Modified 9 years, 1 month ago Viewed 37k times 5 object selectedDataItem; MyClass.Inventory inventory; inventory = (MyClass.Inventory) selectedDataItem; in inventory we can see the details such as: Trace.Writeline (inventory.Name + " " + inventory.Place); Returns the elements of the specified sequence or the specified value in a singleton collection if the sequence is empty. #, Dec 12 '08 What do gun control advocates mean when they say "Owning a gun makes you more likely to be a victim of a violent crime."? I know that the object implements IEnumerable<object> but I don't know what type it is. I know that the object implements IEnumerable but I don't know what type it is. How to print and connect to printer using flutter desktop via usb? Sign in to post your reply or Sign up for a free account. If MyClass<T> is initialized as for example MyClass<List<string>> then T = List<string> so the overloaded definition won't actually get invoked. Enumerates a sequence, produces an immutable sorted set of its contents, and uses the specified comparer. I really need this to work because this method needs to be very generic to receive single objects and collections both of unspecified types. //Yourcollection,asCollectionforsimplicity'ssake. This allows a generic collection to be passed to a method that expects an IEnumerable object. If an element cannot be converted to type TResult, this method throws a InvalidCastException. Not sure why do you need this, but once i saw next extension method: inventory is an instance of class MyClass.Inventory and its not an enumerable list so that you can cast it directly. [Solved]-Cast from IEnumerable to IEnumerable<object>-LINQ,C# Correlates the elements of two sequences based on matching keys. Some information relates to prerelease product that may be substantially modified before its released. Does .NET offer any collection class which will give me objects last The specified seed value is used as the initial accumulator value, and the specified function is used to select the result value. Invokes a transform function on each element of a sequence and returns the maximum nullable Int32 value. C# cast object of type int to nullable enum, Unable to cast object of type ServiceCollection to type 'Autofac.ContainerBuilder' using dotnet core and autofac. class Employee { public string Name; public int Years; public string Department; } Then (in a seperate class) I have the following code fragments (I think i understand all but the last): I believe that the following code fragment works because the array initiliser creates an array of Employee objects which are . On the other hand, if you still want to use IEnumerable, use List, store your object in it, and then do the LINQ query! This allows a generic collection to be passed to a method that expects an IEnumerable object. return single instance object as IEnumerable, Performance of Skip (and similar functions, like Take), How to cast a SQL bigint to C# equivalent. Groups the elements of a sequence according to a specified key selector function and compares the keys by using a specified comparer. As for why your provided sample doesn't work: I still think var can make code more readable in some cases. c# - Cast from IEnumerable to IEnumerable - Stack Overflow Returns the element at a specified index in a sequence. Casts the elements of an IEnumerable to the specified type. Thanks, Pritesh Ostwal Returns the only element of a sequence, and throws an exception if there is not exactly one element in the sequence. http://www.devarticles.com/c/a/C-Sharp/Interface-IEnumerable-and-IEnumerator-in-C-sharp/2/ Projects each element of a sequence to an IEnumerable, flattens the resulting sequences into one sequence, and invokes a result selector function on each element therein. Why does awk -F work for most letters, but not for the letter "t"? Invokes a transform function on each element of a sequence and returns the maximum nullable Decimal value. To obtain only those elements that can be converted to type TResult, use the OfType method instead of Cast(IEnumerable). How do I provide a custom model binder for a property on a model from body? Returns the minimum value in a generic sequence according to a specified key selector function. This is also creating a new list, rather than casting the original one. Sorts the elements of a sequence in descending order. Returns the first element of a sequence, or a specified default value if the sequence contains no elements. We can also use the typecasting method to store an object of the List data type into an object of the IEnumerable data type, as . Produces the set union of two sequences by using the default equality comparer. Do not be mistaken - IEnumerable<string> doesn't implement IEnumerable<object> - the only reason you can cast IEnumerable<string> to IEnumerable<object> is that IEnumerable<T> is co-variant. in inventory we can see the details such as: You see inventory has inventory.Name, Inventory.Place I want to wrap all of the property inside IEnumerable or ObservableCollection so that I can iterate through all of the inventory at once and not by inventory.Name, inventory.Place etc etc How can I make inventory IEnumerable so that I can do something like this : Unable to cast object of type 'MyClass.Inventory' to type 'System.Collections.Generic.IEnumerable`1[MyClass.Inventory]'. (nullable decimal), Cast sender object in event handler using GetType().Name. Returns the elements of the specified sequence or the type parameter's default value in a singleton collection if the sequence is empty. Cast - Using C# LINQ - A Practical Overview - CodinGame How to troubleshoot crashes detected by Google Play Store for Flutter app, Cupertino DateTime picker interfering with scroll behaviour. Converts an IEnumerable to an IQueryable. If you really want an enumerable with that object then you need to create an empty enumerable and add that object to it. Join Bytes to post your question to a community of 472,487 software developers and data experts. Invokes a transform function on each element of a sequence and returns the minimum Double value. Converts a generic IEnumerable to a generic IQueryable. Why Enumerable.Cast raises an InvalidCastException? If the data you're dealing with is not iterable, making it an IEnumerable makes no sense. I have a class that defines one, An element in the sequence cannot be cast to type TResult. 585), Starting the Prompt Design Site: A New Home in our Stack Exchange Neighborhood, Temporary policy: Generative AI (e.g., ChatGPT) is banned. But I always end up with the following excepction: Unable to cast object of type 'System.Collections.Generic.List1[MySpecificType]' to type 'System.Collections.Generic.List1[System.Object]'. Method/Function: Cast Examples at hotexamples.com: 30 Frequently Used Methods Show Example #1 1 Show file File: PropertyExpression.cs Project: tfreitasleal/MvvmFx Famous papers published in annotated form? Why Is PNG file with Drop Shadow in Flutter Web App Grainy? Computes the average of a sequence of Decimal values that are obtained by invoking a transform function on each element of the input sequence. inventory is an instance of class MyClass.Inventory and its not an enumerable list so that you can cast it directly. Func, Func, IComparer, IEqualityComparer), ToImmutableSortedSet(IEnumerable), ToImmutableSortedSet(IEnumerable, IComparer), CopyToDataTable(IEnumerable, DataTable, LoadOption), CopyToDataTable(IEnumerable, DataTable, LoadOption, FillErrorEventHandler), Aggregate(IEnumerable, Func), Aggregate(IEnumerable, TAccumulate, Func), Aggregate(IEnumerable, TAccumulate, Func, Func), All(IEnumerable, Func), Any(IEnumerable, Func), Append(IEnumerable, TSource), AsEnumerable(IEnumerable), Average(IEnumerable, Func), Average(IEnumerable, Func), Average(IEnumerable, Func), Average(IEnumerable, Func), Average(IEnumerable, Func>), Average(IEnumerable, Func>), Average(IEnumerable, Func>), Average(IEnumerable, Func>), Average(IEnumerable, Func>), Average(IEnumerable, Func), Chunk(IEnumerable, Int32), Concat(IEnumerable, IEnumerable), Contains(IEnumerable, TSource), Contains(IEnumerable, TSource, IEqualityComparer), Count(IEnumerable, Func), DefaultIfEmpty(IEnumerable), DefaultIfEmpty(IEnumerable, TSource), Distinct(IEnumerable, IEqualityComparer), DistinctBy(IEnumerable, Func), DistinctBy(IEnumerable, Func, IEqualityComparer), ElementAt(IEnumerable, Index), ElementAt(IEnumerable, Int32), ElementAtOrDefault(IEnumerable, Index), ElementAtOrDefault(IEnumerable, Int32), Except(IEnumerable, IEnumerable), Except(IEnumerable, IEnumerable, IEqualityComparer), ExceptBy(IEnumerable, IEnumerable, Func), ExceptBy(IEnumerable, IEnumerable, Func, IEqualityComparer), First(IEnumerable, Func), FirstOrDefault(IEnumerable), FirstOrDefault(IEnumerable, TSource), FirstOrDefault(IEnumerable, Func), FirstOrDefault(IEnumerable, Func, TSource), GroupBy(IEnumerable, Func), GroupBy(IEnumerable, Func, IEqualityComparer), GroupBy(IEnumerable, Func, Func), GroupBy(IEnumerable, Func, Func, IEqualityComparer), GroupBy(IEnumerable, Func, Func,TResult>), GroupBy(IEnumerable, Func, Func,TResult>, IEqualityComparer), GroupBy(IEnumerable, Func, Func, Func,TResult>), GroupBy(IEnumerable, Func to compare values. Unable to cast COM object of type exception, C# - Need ideas on executing SQL and exporting to excel. Determines whether all elements of a sequence satisfy a condition. Faced with a problem, element.click() event doesn't work in Safari browser. Correlates the elements of two sequences based on matching keys. Determines whether a sequence contains a specified element by using a specified IEqualityComparer. PropertyInfomyProperty=this.GetType().GetProperty(p_propertyName); objectres=myProperty.GetValue(this,null);//thisisthefullyloadedInsuredobjectinthiscase, Ift.GetInterfaces().Contains(IEnumerable)Then, ReturnDirectCast(ReceivedObject,IEnumerable), ElseIft.GetInterfaces().Contains(IList)Then, DimsAsString=TryCast(mystring,string), DimsAsString=DirectCast(MyObj,String). @erikkallen, True, but this is something that the OP should be aware of. Determines whether two sequences are equal by comparing the elements by using the default equality comparer for their type. Making statements based on opinion; back them up with references or personal experience. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. In general that would be a bad practice. Parameters source IEnumerable Computes the sum of the sequence of nullable Double values that are obtained by invoking a transform function on each element of the input sequence. What you actually need to do is use only a single method but have a clause to test if T implements IEnumerable<T>. It's surprising, since int derives from object, right? The Cast<U> () method casts each element of a source IEnumerable<T> sequence, individually, to a base or derived type U and returns a sequence containing all of the resultant elements. You can't cast an IEnumerable to a List. The following example demonstrates how to implement the IEnumerable interface and how to use that implementation to create a LINQ query. I'm using NHibernate 1.2 (CR1), and I'm using a custom list (inherited from Returns the first element of the sequence that satisfies a condition, or a specified default value if no such element is found. c# - Casting array to IEnumerable<T> - Stack Overflow Everything works except that I get the error: Returns the first element of a sequence, or a default value if the sequence contains no elements. Describing characters of a reductive group in terms of characters of maximal torus. An IEnumerable that contains each element of the source sequence cast to the specified type. If the object you receive is not an enumerable or a derivate it won't work. What are some ways a planet many times larger than Earth could have a mass barely any larger than Earths? Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support. Thanks for contributing an answer to Stack Overflow! Convert List to IEnumerable in C# - Best Tutorial About Python To learn more, see our tips on writing great answers. How to professionally decline nightlife drinking with colleagues on international trip to Japan? I don't know why this is downvoted, so far this is the answer which addresses the core problem that, How Bloombergs engineers built a culture of knowledge sharing, Making computer science more humane at Carnegie Mellon (ep. The start time is equivalent to 19:00 (7PM) in Central How do I cast an object to an ArrayList or IEnumerable? ASP.NET MVC Web API: passing in a value that can either be a string or an array of ints, Converting a object into a List C#. Sorts the elements of a sequence in ascending order by using a specified comparer. Thanks for contributing an answer to Stack Overflow! Sorts the elements of a sequence in ascending order according to a key.