Australia to west & east coast US: which order is better? By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. rev2023.6.29.43520. For the ID + name I'd use: Or you could just change your ProductToString method, of course. VB.net How do I manually/explicitly convert an array to an ObjectCollection? Casting reference types doesn't change representation - it's still the same reference, referencing the same object. Some of them are enumerable. Is it possible to "get" quaternions without specifically postulating them? Does a simple syntax stack based language need a parser? 'System.Collections.Generic.IEnumerable`1[System.Object]'. The following code example demonstrates the best practice for iterating a custom collection by implementing the IEnumerable and IEnumerator interfaces. I'm trying to figure out how I can loop over those ones without knowing their exact type. Does the Frequentist approach to forecasting ignore uncertainty in the parameter's value? If a polymorphed player gets mummy rot, does it persist when they leave their polymorphed form? I didn't even know they added that in C#4! Alternatively, you could override ToString() in Product, if this is usually how you want to convert a Product to a string. Thanks for contributing an answer to Stack Overflow! I want to compare two datagridviews, and use the Except method on the IEnumerable interface, in order to { Nowadays it's like: var collection = new List
(objectVar); Does your Method2 really care what type it gets? Holly god! C# 4 will have covariant and contravariant template parameters, but until then you have to do something nongeneric like IList collection = (IList)m To learn more, see our tips on writing great answers. If not, you could just call Cast(): If you definitely need to get the right type, you'll need to use reflection. Connect and share knowledge within a single location that is structured and easy to search. enumerable = MyObject as
IEnumerable contains a single method, GetEnumerator, which returns an IEnumerator. Do I owe my company "fair warning" about issues that won't be solved, before giving notice? IEnumerable implements IEnumerable so you can always cast "downwards", @Pauli: yes, but the problem I was experiencing was that, correct, and which you may have realized by now IEnumerable is not the same as IEnumerable even though both their Enumerators return object :). Is there any way to cast / convert / invoke via reflection to IEnumerable not knowing the type at compile time? For more information about Not the answer you're looking for? In Solution Explorer, right-click the Class1.vb file and click Rename. How Bloombergs engineers built a culture of knowledge sharing, Making computer science more humane at Carnegie Mellon (ep. You simply need to add the items to a new list: if (myObject is IEnumerable) { List list = new why does music become less harmonic if we transpose it down to the extreme low end of the piano? This enumerable class will read lines from a text file one line at a time. Visit Microsoft Q&A to post new questions. How can I handle a daughter who says she doesn't want to stay with me more than one day? However, if you can't apply this in your context, then Guffa's answer is the way to go. My code is: So, I have tried the IEnumerable.Except, but it seems that my itemArray() is a object, cause I got the message "System.linq.Enumerable+d_99'1[System.Object]", when I try to try to cast exceptItems, as follows: And know I get the err. You need to type cast using as operator like this. private void MyMethod(object myObject) What is the difference between Cast List and Cast always returns false. Was the phrase "The world is yours" used as an actual Pan American advertisement? Is it legal to bill a company that made contact for a business proposal, then withdrew based on their policies that existed when they made contact? The enumerator class opens the text file and performs the file I/O to read the lines from the file. thanks! Why it is called "BatchNorm" not "Batch Standardize"? Dim reference1 As IEnumerable(Of 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. How to cast an `IEnumerable` to `IEnumerable`. The method I am writing is passed a parameter of type object. Connect and share knowledge within a single location that is structured and easy to search. 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. To learn more, see our tips on writing great answers. 585), Starting the Prompt Design Site: A New Home in our Stack Exchange Neighborhood, Temporary policy: Generative AI (e.g., ChatGPT) is banned, Cast array in Object variable to type in System.Type variable, Easy way to cast an object array into another type in C#. Convert / Cast IEnumerable to IEnumerable, How Bloombergs engineers built a culture of knowledge sharing, Making computer science more humane at Carnegie Mellon (ep. To learn more, see our tips on writing great answers. Create a method to work on IEnumerable of all types (type unknown at design run-time), Freely convert between List and IEnumerable. Counting Rows where values can be stored in multiple columns. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, The future of collective knowledge sharing. How could a language make the loop-and-a-half less error-prone? Difference between and in a sentence, 1960s? You could then either use a method group conversion or a lambda expression to call ToString. I think the problem is that I have to convert itemArray() into an IEnumerable, is there any way that I could do this without major changes in my code? I suggest you refer keyword IS
{ { Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. I was starting to think the code was getting a bit smelly. Casting the object reference to an integer array reference works fine: You can cast each integer in the array to an object to create an object array with the values from the integer array: As you edited your question to include any type of array, not just an integer array, casting to IEnumerable as you suggested works fine as any type can still be cast to Object in the next step: As far as I know, you can't just cast an array of Integer to an array of Object. I am using reflection and executing a method that returns object as a result(DB returns list of customers). if(myObject is IEnumerable) Uber in Germany (esp. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. The implementation of the Current property of the IEnumerator interface can be made Private, because you have to expose only members of the IEnumerator(Of String) interface. The MoveNext method of the IEnumerator interface navigates to the next item in the text file and updates the value that is returned by the Current property. You can create a class that implements the IEnumerable interface to expose source data as enumerable data. Same issue. string is an IEnumerable, so it cannot be That is why you get if only when you enumerate over it. I see that converting object to byte array and then bytearray to List works..But that's not what it shud be. What do you do with graduate students who don't want to work, sit around talk all day, and are negative such that others don't want to be there? In the code base I'm working in there have a method that has the signature. Please check the following code snippets. To learn more, see our tips on writing great answers. Asking for help, clarification, or responding to other answers. Construction of two uncountable sequences which are "interleaved". 585), Starting the Prompt Design Site: A New Home in our Stack Exchange Neighborhood, Temporary policy: Generative AI (e.g., ChatGPT) is banned, How to convert Array to ArrayList in VB.Net. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, The future of collective knowledge sharing. 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. What are some ways a planet many times larger than Earth could have a mass barely any larger than Earths? Why is there inconsistency about integral numbers of protons in NMR in the Clayden: Organic Chemistry 2nd ed.? list = t;(Won't workNeed to do explicit converstion ?? Using Cast() method will cause to boxing of value types and it may have an performance issues for big collections. Unable to cast object of type 'System.Collections.Generic.List[list_cast_object_test.Apple]' to type Since you don't have option strict, the compiler doesn't know what type your itemArray() is so it uses the lowest common denominator of object. How to inform a co-worker about a lacking technical skill without sounding condescending. The following example shows the StreamReaderEnumerable in a LINQ query. I have an object received from service call. That is correct. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. 2. Is it usual and/or healthy for Ph.D. students to do part-time jobs outside academia? As mentioned in other answers, the solution is to cast to non-generic IEnumerable. You can use an enumerable class in your code together with control structures that require an object that implements IEnumerable, such as a For Next loop or a LINQ query. Did the ISS modules have Flight Termination Systems when they launched? The Visual Studio edition that you have and the settings that you use determine these elements. @dryman you are right, it's my fail. To learn more, see our tips on writing great answers. Why do so many named collections in .NET not implement IEnumerable? The Current properties for both the IEnumerator(Of String) and IEnumerator interfaces return the current item from the text file as a String. That's cool. Alas I'm not familiar with how yo create a new object in visual basic, but it will be similar to the folowing: This is probably wrong, but you get the gist. IEnumerable; Could you please provide the type of MyObject or provide the code snippet for MyObject to us in your reply? The problem is not with the Linq, it arises from the ForNext loop. Idiom for someone acting extremely out of character. Grappling and disarming - when and why (or why not)? 585), Starting the Prompt Design Site: A New Home in our Stack Exchange Neighborhood, Temporary policy: Generative AI (e.g., ChatGPT) is banned, cast an object to an Object() with nullable dates, Cast Linq IEnumerable to Class that inherits Ienumerable, Casting List to IEnumerable, Casting object to generic IEnumerable with only type available, Casting a Collection of Objects to IEnumerable(Of Type), Convert object to IEnumerable in .NET 2.0, How to cast an IEnumerable to an IEnumerable, Casting an object into the same type as an IEnumerable collection, Insert records of user Selected Object without knowing object first, Short story about a man sacrificing himself to fix a solar sail. VB.net How do I manually/explicitly convert an array to an ObjectCollection? The application uses a LINQ query to return lines from the file that match the specified criteria. Why would a god stop using an avatar's body? How to inform a co-worker about a lacking technical skill without sounding condescending. Find centralized, trusted content and collaborate around the technologies you use most. Asking for help, clarification, or responding to other answers. 585), Starting the Prompt Design Site: A New Home in our Stack Exchange Neighborhood, Temporary policy: Generative AI (e.g., ChatGPT) is banned, Calculating Count for IEnumerable (Non Generic), Did I really just put a string data type into an IEnumerable, Casting object to generic IEnumerable with only type available, Converting from IEnumerable> to ICollection, How to cast an IEnumerable to an IEnumerable. Other than heat. Unable to cast object of type 'VB$AnonymousType_0`2 [System.Int64,System.String]' to type 'People'. Casts the elements of an IEnumerable to the specified type. You probably want to refactor your code to use IEnumerable.Cast. For the generic version of this interface see System.Collections.Generic.IEnumerable. No, you won't be able to cast a reference type as a value type (which is what the Structure constraint signified). This is also an approach for moving from IQueryable to IQueryable (applicable to other such scenarios.) To learn more, see our tips on writing great answers. Why would a god stop using an avatar's body? Cast from IEnumerable to IEnumerable. I can assume that this is an IEnumerable of some kind, however due to the interface contract I must accept it as an object rather than directly as an IEnumerable. In this walkthrough, you will create a class that implements the IEnumerable(Of String) interface and a class that implements the IEnumerator(Of String) interface to read a text file one line at a time. 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. It could be an array, a List, or whatever. Is Logistic Regression a classification or prediction model? How can I handle a daughter who says she doesn't want to stay with me more than one day? Yeah, this is old legacy code and yes, I agree with you that the object should be created correctly but it wasn't in a lot of places. The advantage of returning data one item at a time is that you do not have to load the complete set of data into memory to work with it. It is a best practice to implement IEnumerable and IEnumerator on your collection classes to enable the foreach (For Each in Visual Basic) syntax, however implementing IEnumerable is not required. Teen builds a spaceship and gets stuck on Mars; "Girl Next Door" uses his prototype to rescue him and also gets stuck on Mars. Because the result of t is IEnumerable
Not the answer you're looking for? Replace the code that Visual Basic generated for the Dispose method with the following code. The IEnumerable interface is implemented by classes that can return a sequence of values one item at a time. Making statements based on opinion; back them up with references or personal experience. How does one convert from an IEnumerable to IEnumerable? To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Select the Class template. or an override to ToString() for the product object so how i can use this method to get the list of string[] from IEnumerable ? c# - Cast object to IEnumerable ? - Stack Overflow Since the author does not know of which type the Enumerable is this won't necessary work always. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Suppose I don't know that the array is Of Integer. If there are no more items to read, the MoveNext method returns False; otherwise the MoveNext method returns True. Cologne and Frankfurt). What do you want to do with it? Do native English speakers regard bawl as an easy word? Why it is called "BatchNorm" not "Batch Standardize"? Thanks for contributing an answer to Stack Overflow! To subscribe to this RSS feed, copy and paste this URL into your RSS reader. interface is covariant, but covariance doesn't work with value types. Renaming the file will also rename the class to StreamReaderEnumerable. How can I handle a daughter who says she doesn't want to stay with me more than one day? Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support. Can renters take advantage of adverse possession under certain situations? and AS. @Gaffa, corrected your answer to use IEnumerable because in my original problem I didn't know that obj was an array of integers, it could be an array of anything. Once you get moved over, you'll be able to call and use all the things you expect and need without fail. The LINQ query could instead query the file contents by using an enumerable class, returning only values that match the search criteria. as operator only perform a cast and return null if the cast fails. I want to compare two datagridviews, and use the Except method on the IEnumerable interface, in order to know the difference among them. Find centralized, trusted content and collaborate around the technologies you use most. Spaced paragraphs vs indented paragraphs in academic textbooks. LaTeX3 how to use content/value of predefined command in token list/string? Dim array1() As String = {"cat", "dog", "mouse"} ' Cast the array to IEnumerable reference. Implementing IEnumerable - Visual Basic | Microsoft Learn