To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Only works with properties (not fields) but it works on Anonymous Types. Thank you Amy. IEnumerable is an interface contained in the System.Collections.Generic namespace. Convert IEnumerable to DataTable, An efficient way to convert from IEnumerable to DataTable, How to convert IEnumerable list to Datatable in C#, C# Convert System.Data.EnumerableRowCollection to DataTable, Convert Datatable to nested list/object using C#. In the above code, we converted the List of integers ilist to the IEnumerable of integers enumerable with the as keyword in C#. They return new ones. @Ronnie - Thanks! How can I convert a DataTable to an IEnumerable>? MoreLINQ includes a .ToDataTable() method. OfType<TResult> (IEnumerable): The elements of the IEnumerable are filtered based on the type mentioned. LINQ and File Directories (C#) That's why there are built-in LINQ extension methods such as IEnumerable.ToList(), that does exactly what you wrote. private static IEnumerable<KeyValuePair<string,string . I just had a little problem with nullable types, that was resolved with tb.Columns.Add(prop.Name, Nullable.GetUnderlyingType(prop.PropertyType) ?? How to convert any datareader into generic list. Asking for help, clarification, or responding to other answers. It's called DataTableProxy and is available as a NuGet package. ;), I've written a library to handle this for me. Example 1 static void Main(string[] args) { List list = new List(); IEnumerable enumerable = Enumerable.Range(1, 5); foreach (var item in enumerable) { list.Add(item); } foreach (var item in list) { Console.WriteLine(item); } Console.ReadLine(); } Output 1 2 3 4 5 Example 2 convert List to IEnumerable Find centralized, trusted content and collaborate around the technologies you use most. How do I distinguish between chords going 'up' and chords going 'down' when writing a harmony? Observe it's a reference value. The content you requested has been removed. Is there a non-combative term for the word "enemy"? Is there an easier way to generate a multiplication table? rev2023.7.3.43523. The values within each group are in the same order as in source. By clicking Post Your Answer, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct. If you use in a large dataset your system will cry. Add a constructor to MyCollection that accepts an IEnumerable, and do: You can't cast, because the LINQ methods don't change your original collection. c# - Return IEnumerable<KeyValuePair> from a private method; use However IQueryProvider typically returns an IEnumerable, which leads to two options: Both ways are much more similar, than you might think, because ToList is implemented somehow like this: So it simply delegates all the hard work to the respective constructor of List. The code posted below is what I have so far, what I need will be to get the propertie of T at index i of DataSource in the outer loop. MathJax reference. Making statements based on opinion; back them up with references or personal experience. They provide powerful filtering, ordering, and grouping capabilities with a minimum of application code. Should I be concerned about the structural integrity of this 100-year-old garage? Lastly apologies for my extensive/excessive comments (I had a anal/mean prof that beat it into me! The following code example uses an explicitly typed range variable to cast a type to a subtype before accessing a member that is available only on the subtype. rev2023.7.3.43523. At least for my use cases (on .Net Core 2.2). Creates a Dictionary from an IEnumerable according to a specified key selector function and key comparer. Here is a variant that is slightly more verbose to use but much simpler to implement: I hope I got it right. AsParallel (IEnumerable): This is used to enable . But as explained by Amy there is a better way. Have to use, However, after implementing the two constructors I get a whole list of errors about how the base type constrcutors are not implemented. In the inner loop then get the values of each property in turn and insert into the object[,]. In addition, LINQ queries offer three main advantages over traditional foreach loops: They are more concise and readable, especially when filtering multiple conditions. From the list of shapes, choose any shape. To learn more, see our tips on writing great answers. Thanks for this. The ItemsSource can be populated with any IEnumerable of objects. But the standard for the project, long long ago and way over my head, was to create the custom collections. Converts a collection to an array. Using your example: foreach (var checkInVar in CheckInVars) { foreach (var prop in checkInVar.GetType ().GetProperties ()) { Console.WriteLine (" {0} = {1 . The Enumerable.ToArray, Enumerable.ToDictionary, Enumerable.ToList, and Enumerable.ToLookup methods can be used to force immediate query execution instead of deferring it until the query is enumerated. While your collection does implement IEnumerable, you can't cast a simple IEnumerable to your specific collection because of how inheritance works. Why did only Pinchas (knew how to) respond? 4 parallel LED's connected on a breadboard. What is the purpose of installing cargo-contract and using it to create Ink! Long time since I last played with this. What does skinner mean in the context of Blade Runner 2049. By not using one of the extension methods but doing this by a simple foreach loop over the KeyValuePair's of the IReadOnlyDictionary this will be more readable and faster, because you only need one loop like so . How do I distinguish between chords going 'up' and chords going 'down' when writing a harmony? The following code example shows us how we can convert a List data structure to an IEnumerable data structure with the AsEnumerable() function of LINQ in C#. LINQ query over generic list of user types, ienumerable to ienumerable without losses, How to cast an `IEnumerable` to `IEnumerable`, Convert IEnumerable to IEnumerable. More info about Internet Explorer and Microsoft Edge. This is a little bit complicated, but in general you can imagine, that LINQ enumerates through your collection (no matter of the type, it is just important, that it can be converted into IQueryable) and adds all matching object references to a new list. This doesn't work if the type is string as the properties are chars and length but the get value then tries to put the full string into the char column. Are throat strikes much more dangerous than other acts of violence (that are legal in say MMA/UFC)? A 2019 answer if you're using .NET Core - use the Nuget ToDataTable library. Why did Kirk decide to maroon Khan and his people instead of turning them over to Starfleet? The best answers are voted up and rise to the top, Not the answer you're looking for? That worked quite excellent. Is the difference between additive groups and multiplicative groups just a matter of notation? Creates a Dictionary from an IEnumerable according to a specified key selector function, a comparer, and an element selector function. You can do this by using the keyword, You mean in this case at least it won't fail at runtime, right? Since you can't index into an enumerable, you should enumerate it in a foreach loop while incrementing a counter, rather than using a for loop. Thanks for contributing an answer to Stack Overflow! Overloads ToDictionary<TSource,TKey,TElement> (IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>) An IEnumerable to create a Dictionary from. Do large language models know what they are talking about? Maisam is a highly skilled and motivated Data Scientist. either you forgot something in the implementation or its purpose is rather non-obvious. It really is my own style (which tends to get me in trouble more times then not) but I too find it makes sooo much sense! Each specialization of your collection could define it's own extension within the scope of it's declaration. Casts the elements of a collection to a specified type. What are some examples of open sets that are NOT neighborhoods? Making statements based on opinion; back them up with references or personal experience. So, 10 years later this is still a thing :). Changing non-standard date timestamp format in CSV using awk/sed. Equivalent idiom for "When it rains in [a place], it drips in [another place]", What should be chosen as country of visit if I take travel insurance for Asian Countries. You can use LINQ to query any enumerable collections such as List<T>, Array, or Dictionary<TKey,TValue>. Asking for help, clarification, or responding to other answers. Does the DM need to declare a Natural 20? Rust smart contracts? Developers use AI tools, they just dont trust them (Ep. But Fast: The Tale of Three Monkeys, A Wolf and the DynamicMethod and ILGenerator Classes, Re: Sorry man. 3 Answers Sorted by: 5 You're pretty close. Should I be concerned about the structural integrity of this 100-year-old garage? In general, the more complex the operation you want to perform on the data, the more benefit you'll realize by using LINQ instead of traditional iteration techniques. Right-click one of the captions and select Replace Smart Shape. He has over 4 years of experience with Python programming language. Explains how LINQ can be used to query and transform strings and collections of strings. In my UI layer I am simply calling the method and passing the id. Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages. Use MathJax to format equations. 586), Starting the Prompt Design Site: A New Home in our Stack Exchange Neighborhood, Testing native, sponsored banner ads on Stack Overflow (starting July 6), Temporary policy: Generative AI (e.g., ChatGPT) is banned, Best way to convert IEnumerable to Datatable for SQL Bulk Copy, How do I Convert List or IEnumerable to DataTable, Returning a DataTable using Entity Framework ExecuteStoreQuery, How to do a Full Outer Join of 2 or more Datatables in C# with a common column. You could create an explicit or implicit cast operator in your class but you would need to implement it in every one of your child classes. What syntax could be used to implement both an exponentiation operator and XOR? Is there any political terminology for the leaders who behave like the agents of a bigger power? and also some ILGenerator powered solutions (FastMember and Fast.Reflection). Something like AsIEnumerable? This member has not yet provided a Biography. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. I would have been happier dealing with everything as List and then custom defining the objects only. We can pass all the values with file path as attachment collection in send outlook mail activity with a list variable attached So to convert the ienumerable to list (of string) Use this expression list_string = match_ienumerable_result.AsQueryable.select (function (x) x.value).ToList () Casting is not allowed, I get the exception "Cannot cast from ". To subscribe to this RSS feed, copy and paste this URL into your RSS reader. That being said, the third and fourth option shouldn't be used. But I really dislike the variable prefixes :). Connect and share knowledge within a single location that is structured and easy to search. Linq Assembly: System.Linq.dll Creates a Dictionary<TKey,TValue> from an IEnumerable<T>. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, The future of collective knowledge sharing, Fair enough, I stole a couple of fixes from your answer, too :-). Following are some examples: The Enumerable.AsEnumerable method can be used to hide a type's custom implementation of a standard query operator. It really helped me. That's why I built this as an extension in the first place, so that I would be able to generate. Why a kite flying at 1000 feet in "figure-of-eight loops" serves to "multiply the pulling effect of the airflow" on the ship to which it is attached? DataReader into IEnumerable with C# - CodeProject Wont give me the answer im looking for since I need something implementable at the base level though, i dont want to have to redefine the constructor in every child class I have/will create. Firstly you need to add a where T:class constraint - you can't call GetValue on value types unless they're passed by ref. Most collections are supporting construction by IEnumerable parameters. If comparer is null, the default equality comparer Default is used to compare keys. How to query an ArrayList with LINQ (C#) Creates a Dictionary from an IEnumerable according to a specified key selector function. Assume it's interesting and varied, and probably something to do with programming. what purpose does the TCollection parameter have? CopyToDataTable: Why exactly does it throw an error if one field is NULL, and how to fix it? Do large language models know what they are talking about? Not the answer you're looking for? Well this is far nicer than the existing ObtainDataTableFromIEnumerable stuff, I would only add changing from List to IEnumerable. rev2023.7.3.43523. A function to extract a key from each element. Do large language models know what they are talking about? Yes. LINQ and Strings (C#) keySelector produces duplicate keys for two elements. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. 10 I have a custom collection type, defined as such: public abstract class RigCollectionBase<T> : Collection<T>, IEnumerable<T>, INotifyPropertyChanged, IBindingList, ICancelAddNew where T : BusinessObjectBase, new () Note: this is the base class, there are 20 or so child classes that are implemented like so: Asking for help, clarification, or responding to other answers. Is there an easier way to generate a multiplication table? Is there a finite abelian group which is not isomorphic to either the additive or multiplicative group of a field? Below are the methods: Cast<TResult> (IEnumerable): The non-generic collection of the IEnumerable interface is converted to the specified type mentioned. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, The future of collective knowledge sharing. Scottish idiom for people talking too much, Name of a movie where a guy is committed to a hospital because he sees patterns in everything and has to make gestures so that the world doesn't end, 4 parallel LED's connected on a breadboard. How do you convert an IEnumerable Object? Rust smart contracts? source or keySelector or elementSelector is null. Find centralized, trusted content and collaborate around the technologies you use most. Convert the List to IEnumerable With the Typecasting Method in, Convert the List to IEnumerable With the LINQ Method in, Get the First Object From List