I'm using mongoDb. Cannot implicitly convert type - List is listed as IEnumerable?. But make sure to return an IEnumerable still - IEnumerable has a dual purpose in that it is very good at representing a read-only collection. Learn more, C# Program to cast a type to its IEnumerable equivalent, Difference between IEnumerator and IEnumerable Interface in C#. Use var and don't create a list at all. Why are lights very bright in most passenger trains, especially at night? Cannot implicitly convert type 'object' to 'string'. You can typecast a List to an IEnumerable, but not the other way around. The immediate return value is an object that stores all the information that is required to perform the action. Find centralized, trusted content and collaborate around the technologies you use most. Microsoft makes no warranties, express or implied, with respect to the information provided here. How can I specify different theory levels for different atoms in Gaussian? Why are lights very bright in most passenger trains, especially at night? Should I sell stocks that are performing well or poorly first? Convert list of string to list of list in Python. How to extract values from a list of dictionaries and group and convert to a single dictionary . If you don't need to change the collection I would change the definition of GetHistory to IEnumerable. Question of Venn Diagrams and Subsets on a Book. you're returning IEnumerable<ProductTypesData> not ActionResult<IEnumerable<ProductTypesData>> Agnib Pyne 2022 7-Feb-23 4:32am Yes. Developers use AI tools, they just dont trust them (Ep. your return type is IEnumerable<ElectorDetail> or List<ElectorDetail> but in your linq, you select new Pe, e.MasterRelationType.RelationTypeDescr } which csharp cannot implicitly convert to IEnummerable<ElectorDetail> what you can do is : create a class(or model) that has e, e.MasterRelationType.RelationTypeDescr properties. Most Recent Solution 2 Assuming that the properties of the anonymous type are actually the same properties the ViewModel has, just adding one word to the query should do the trick: C# In the final act, how to drop clues without causing players to feel "cheated" they didn't find them sooner? The Cast(IEnumerable) method enables the standard query operators to be invoked on non-generic collections by supplying the necessary type information. Cannot implicitly convert type 'System.Collections.Generic.IEnumerable<T>' to 'Microsoft.AspNetCore.Mvc.ActionResult<System.Collections.Generic.IEnumerable<T>> aspnet/Mvc#8061 rcollette mentioned this issue on Jul 23, 2018 Limitation of ActionResult<T> not mentioned dotnet/AspNetCore.Docs#7777 msftbot bot locked as on Dec 3, 2019 Cannot implicitly convert type 'System.Collections.Generic.IEnumerable<URL>' to 'System.Collections.Generic.List<URL>'. //countries.ToList() convert the data collection into the list. An IEnumerable backed by a database should not be lazily evaluated, as the connection it was bound to can potentially be closed by the time it is enumerated. When the IObservable is first observed, the resource is created. You can append this method to your query in order to obtain a cached copy of the query results. 2 Answers. Encryption and Descyption issue in Flutter and C#, Encrypt a file in c# and decrypt in flutter, How many socket will open while listening firestore by DocumentReference. 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. IEnumerable for the lazy methods makes perfect sense. He loves taking on new challenges and believes conceptual programming theories should be implemented in reality. The ToArray<TSource>(IEnumerable<TSource>) method forces immediate query evaluation and returns an array that contains the query results. Shall I mention I'm a heavy user of the product at the company I'm at applying at and making an income from it? Do large language models know what they are talking about? The source sequence for this method is IEnumerable, which means the elements have the compile-time static type of object. If you would like to change your settings or withdraw consent at any time, the link to do so is in our privacy policy accessible from our home page.. Thanks for your answer, but I'm a bit confused, you're asking what the code that calls it does then saying I shouldn't care about what the caller does. Okay, I also tried it and it did work, but I am just puzzles as to why one of the lists is considered an IEnumerable. cannot convert to 'System.Collections.IEnumerable' I tried both: Root data = JsonSerializer.Deserialize<Root> (result); and: Root data = (Root)JsonSerializer.Deserialize<IEnumerable<Root>> (result); This is my code: Continue with Recommended Cookies. Not the answer you're looking for? Do large language models know what they are talking about? Does a Michigan law make it a felony to purposefully use the wrong gender pronouns? How to convert IEnumerable to List and List back to IEnumerable in C An observable is a class that can be observed, and is lazily evaluated - much like IEnumerable. Safe to drive back home with torn ball joint boot? Stack Exchange network consists of 182 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. All Rights Reserved. In fact, IObservable implements IEnumerable. Whether or not he'll run into concurrency issues highly depends on what he's exposing/doing with the results. To 'bool'. Does code that calls the method always expect List functionality (access by index, etc.)? I guess I meant "overly generalized statement". Convert System.Collection.Generic.IEnumerable<System.Text Use the select clause of a query to perform other conversion types, like the implicit numeric conversions. The detail of its parameter is as follows. 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. Why is it better to control a vertical/horizontal than diagonal? C# List To IEnumerable Using .AsEnumerable () Method Using Linq, we can use the .AsEnumerable () method in C# which is available to us on Lists. Convert an IEnumerable to a List in C# | Delft Stack Thanks for contributing an answer to Code Review Stack Exchange! A List that contains elements from the input sequence. Solution 5 Thank you so much, it worked fine to me (.ToList();), This List class also provides the methods to search, sort, and manipulate lists. Converting models into a list of ViewModels [closed] 20 Bay Street, 11th Floor Toronto, Ontario, Canada M5J 2N8 Compiler Error CS0266 | Microsoft Learn Any caller that gets an IEnumerable result knows that if they want indexed access of the result, they will have to convert to a List, because IEnumerable simple isn't capable of it until it's been enumerated and put into an indexed structure. A List in C# already implements an IEnumerable but you may still feel the need to convert a List to IEnumerable in C#. It does sound like one to look into. In a query expression, an explicitly typed iteration variable translates to an invocation of Cast(IEnumerable). rev2023.7.3.43523. 7 Likes Change method signature to return List, cause you already do that, Other workarounds would be to cast method call result to List, If you do not need List functionality, you could define calledList as IEnumerable. 1. What does the interface IEnumerable do in C#? How to print and connect to printer using flutter desktop via usb? I have the following code: public abstract class BaseViewModel<PrimaryKey, ModelType> { //Some base fields public static List<T> Convert<T>(IEnumerable<ModelType> Stack Exchange Network Stack Exchange network consists of 182 Q&A communities including Stack Overflow , the largest, most trusted online community for developers to learn, share . You need to call ToList at the end of your Select in order to get back a list, instead of an IEnumerable. Alternately, you should assign the return value to an IEnumerable variable instead of a List. Below is an example code to convert IEnumerable to list in C#. Your definition of the GetHistory methods returns an IEnumerable, and you are assigning it to an IList. Why Is PNG file with Drop Shadow in Flutter Web App Grainy? You can typecast a List to an IEnumerable, but not the other way around. cannot convert from System.Collections.Generic.List<> to System Is the executive branch obligated to enforce the Supreme Court's decision on affirmative action? In some applications this solution might not be viable due to the performance impact, and you might feel uneasy about the loss of control here (this is where IoC comes in handy). passerbycmc, Aug 15, 2016. Cannot implicitly convert type 'System.Collections.Generic.IEnumerable We don't need the source of your whole project for such a compilation error. IEnumerable to List C #, What is the best way to get this data? Enumerable.Cast<TResult>(IEnumerable) Method (System.Linq) Thanks for contributing an answer to Stack Overflow! I have been using C# with Unity3d for a few years now, but am just starting with .NET programming. Can we convert an array to list and back in Java? Difference between machine language and machine code, maybe in the C64 community? Cannot convert IQueryable to Generlic List EF 4. The query represented by this method is not executed until the object is enumerated either by calling its GetEnumerator method directly or by using foreach in C# or For Each in Visual Basic. To get things working you just need to change the return type of your GetHistory() method to List. c# - Cannot convert type IEnumerable to List - Stack Overflow Return a List. First story to suggest some successor to steam power? How to convert list to dictionary in Python? [Solved] Cannot implicitly convert type 'System.Linq.IQueryable But I would say that having a lazily evaluated structure coming straight from the DB layer and leaving the DB layer is likely to be a, "harsh" was a poor choice of words on my part. You can append this method to your query in order to obtain a cached copy of the query results. An explicit conversion exists (are you missing a cast? ) Use MathJax to format equations. ), Cannot implicitly convert type 'system.collections.generic.ienumerable' to 'parse.parseobject'. Maybe you could be a little more specific : where are you getting this error? An IEnumerable that contains each element of the source sequence cast to the specified type. cannot convert from 'System.Collections.Generic.List<>' to CS8625 - Cannot convert null literal to non-nullable reference type. linq to entities cannot convert type Icollection to type List. Lateral loading strength of a bicycle wheel, Equivalent idiom for "When it rains in [a place], it drips in [another place]". Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. The program below shows how we can use ToList() method to convert an IEnumerable to a list. I get the error: Cannot implicitly convert type 'System.Collections.Generic.IEnumerable' to 'System.Collections.Generic.List'. Non-anarchists often say the existence of prisons deters violent crime. This will limit you to (without further manipulation) the IEnumerable methods (you can do a foreach and use LINQ things like .First, but you can't reference by specific position, for example). Other conversion types, such as those between different numeric types, are not allowed. rev2023.7.3.43523. [Solved]-Cannot convert from IEnumerable<List> to List-LINQ,C# Awesome! How to troubleshoot crashes detected by Google Play Store for Flutter app, Cupertino DateTime picker interfering with scroll behaviour. In MVC? In addition to that, you might consider whether GetHistory needs to be explicitly called at all - perhaps the equivalent code should be implicitly executed when the URLs getter is first called? I have been using C# with Unity3d for a few years now, but am just starting with .NET programming. Assume only IEnumerable functionality is required by the caller and my question can be reworded into: How do I signify to the caller that each enumeration may be expensive? If you call ToList() just return an IList or ICollection. Your definition of the GetHistory methods returns an IEnumerable, and you are assigning it to an IList. There is a framework called Rx (Reactive Extensions) for .NET that actually has a feature in this built in called Observable.Using(). Thanks, Katie Srini84 (Srinivas) June 15, 2020, 2:49pm 2 Hello @Katie_Vooght You need to place for each and inside for each you can assign a variable to make that string Eg: Mark as solution if this helps for you Thanks 1 Like Should it care about whether the caller might enumerate it several times or not? The content must be between 30 and 50000 characters. The C# List class represents a collection of strongly typed objects that can be accessed by index. Code Review Stack Exchange is a question and answer site for peer programmer code reviews. List<eventgroup> eventt_grp1 = lstGroup.Select (r => new {r.ID, r.Name }).ToList (); If you don't want to use var, you need to define a class that has ID and Name properties. When the IObservable is finished being observed, the resource is Dispose()d. Neat and tidy. How can I specify different theory levels for different atoms in Gaussian? This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL). from i in table2.ToList () join m in Module on e.Module_Id equals m.Id into table3. Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. You get that error because myClass.GetHistory(); returns IEnumerable, which is not same as List at compile time, although it is actually List at runtime. The only type conversions that are performed by this method are reference conversions and unboxing conversions. Just make it clear. IMHO, this will also not work because the result has to be in a the generic list that is expecting some type and the projected type is anonymous and thus we will never be able to specify the type of list of the result type variable.

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