C# return list of objects

So I have moved from working with Java to C# and man is Spring boot different from C#. I am trying to return a list of objects to a rest API using mongodb database. But the result does not return a list, but rather some object containing my list. Brand clas You defined the method to return a List<string>, but you're returning a List<POCount>. You can either change the method (to return a list of POCount objects), or convert this to a List<string>. For example, if you wanted to return a list of the poID values as strings, you could use: return POcountList.Select (po => po.poID).ToList () Learn how query collections using LINQ in C#. In this article. This example shows how to perform a simple query over a list of Student objects. Each Student object contains some basic information about the student, and a list that represents the student's scores on four examinations.. This application serves as the framework for many other examples in this section that use the same students. A list is a collection of items that can be accessed by index and provides functionality to search, sort and manipulate list items. Here we see how to create a list of objects with C# How To Return Different Types Of Objects In C# Based On A Input Parameter Type. Kapil Gaur; see here that we have created a full object that is of DerivedClass and we have written a method in DerivedClass to return the ChildClass object of the same DerivedClass object using Casting. Though we have created an object DerivedObj which is.

When considering the property accessor: if you do just return IEnumerable<string> instead of List<string> by doing return _list (+implicit cast to IEnumerable) then this list can be cast back into List<string> and changed and the changes will propagate into the main object. You can do return new List<string>( _list ) (+subsequent implicit cast. Return value: This method returns a List<T> containing all the elements that match the conditions defined by the specified predicate otherwise it returns an empty List<T>. Exception: This method will give ArgumentNullException if the match is null. Below programs illustrate the use of List<T>.FindAll(Predicate<T>) Method:. Example 1

What if you have an List of class objects? Well, lets look at how we can use C# return index of a object in a List. Create a simple Address Class We will use a simple Address class to demostrate how to find an specific object in a list Explanation: In the above example, we have a class named as Example.Example class contains setdata() method which is used to set the value of str, and Display() method is used to display the value of str, and Astr() is used to add the value of passed object in current object and adding the sum in another object. In Main method, three objects o1, o2, and o3 of Example class are created The Predicate<T> is a delegate to a method that returns true if the object passed to it matches the conditions defined in the delegate. The elements of the current List<T> are individually passed to the Predicate<T> delegate, moving forward in the List<T>, starting with the first element and ending with the last element How To write a generic class in C# to return a List of objects or just a simple string based on a condition ? Please Sign up or sign in to vote. 3.50/5 (4 votes) See more: C#2.0. C#. generics. Hi, I have a webservice which has a method that returns a List of Payment objects provided with some input parameters. However if the input parameters. Inside the GetCustomers method, the records from the Customers Table are fetched using SqlDataReader and then using WHILE Loop, the records are copied into the Generic List collection of Customer class objects. Finally, the Generic List collection of Customer class objects is returned

c# - Http request how to return a list of objects - Stack

  1. C# - List<T> The List<T> is a collection of strongly typed objects that can be accessed by index and having methods for sorting, searching, and modifying list. It is the generic version of the ArrayList that comes under System.Collection.Generic namespace
  2. Different Ways of Creating a List of Objects in C#. The first one will add the N number of objects to the list. The second one will return the collection of N number of objects. 30
  3. g, and through the C++ years, programmers have been returning multi-valued Arrays and Structures, and Objects from functions. C# allows more varied object-types and data-types, and the compiler-support for new source code syntax makes it a little easier. But the design concept and overall pattern is the same
  4. public List<patient> Patientlog(string Username, string Password) {} and i want to return 2 list from this method.I used something like tuples and reference but no use please give some suggestions to fix this issue. i want to return like public List<patient> Patientlog(string Username, string Password
  5. C# - ArrayList. In C#, the ArrayList is a non-generic collection of objects whose size increases dynamically. It is the same as Array except that its size increases dynamically.. An ArrayList can be used to add unknown data where you don't know the types and the size of the data.. Create an ArrayList. The ArrayList class included in the System.Collections namespace
  6. Read from SQL database table, store in list of objects. Ask Question. Asked 9 years, 11 months ago. Active 6 years, 2 months ago. Viewed 29k times. 6. IList<WebSite> wsl = new List<WebSite> (); 1 l = new 1 (); string q = select Id, DomainUrl, IsApproved, Date from website where UserId = @UserId; using (MySqlConnection con = new.

PersonResultList = PersonResultList.Where (pr => PersonList.FirstOrDefault (p => pr.PersonId == p.PersonId) != null && PersonList.FirstOrDefault (p => pr.PersonId == p.PersonId).Gender == female); This works apparently well, however, I must iterate twice through PersonList to check if the person exist and its gender This is a C# example code that shows you how to convert an ms-sql command or stored procedure to a list of objects in C#. How? Table Content. Prepare sql statement; Prepare data object; DataTable. Convert List Object to JSON in C#. Venki October 28, 2015. Conversion of object to Json is pretty simple, can be easily achieved by adding Newtonsoft JSON.NET dll to the solution. While the object is list follow the below code to convert to the pure JSON format

How to return a populated list/class in c

Value : 10 Value : 20 Value : 30. In above program, we are creating a user define class named Sample. It contains a data member value. We create method AddOb (), it returns sum of current object and passed object into this method. Here, AddOb () method is returning the object SortedList.GetValueList Method is used to get the list of keys in a SortedList object.. Syntax: public virtual System.Collections.IList GetValueList (); Return Value: It returns an IList object containing the values in the SortedList object. Below programs illustrate the use of above-discussed method I have two lists of objects Person and PersonResult.Both are linked through the property PersonId.I need to create a filter for the list of PersonResult that meet certain criteria for the Person (e.g. Person.Gender == female).. Im currently using the following LINQ query to achieve this How to get only specific data type of items from list in C#. We'll solve this problem by using .OfType (a LINQ method). There will be a list of objects from which we have to extract only integers from it. we tend to loop over the content and try to find out the type of each item and store that in another list and return that back

Query a collection of objects (LINQ in C#) Microsoft Doc

  1. Or from the File menu, select New and then Project. In the Templates pane, select Installed Templates and expand Visual C# node and select web. In the list of project Templates, select ASP.NET Web Application and click OK. And give your Project name Like StudentApp. In the new ASP.NET Project dialog, select Web API and Click Ok
  2. List<AppIcon> ApplicationIcons = new List<AppIcon> ();var result = from a in ApplicationIcons where a.Id.ToString () == (sender as Image).Tag select a; Console.WriteLine ( (result as AppIcon).Description); I thought that the above code would give me my object where the Id matches the Tag of my image. So instead of doing a for loop thru my list.
  3. To make serializing and deserializing objects easier, the class includes the methods ToJson and FromJson. The ToJson method shown in the following code returns a JSON representation of an object. // Return the JSON serialization of the object. public string ToJson() { // Make a stream to serialize into

How To Create A List Of Objects In C# - C# Corne

The following WebMethod (PageMethod) will return JSON data (object). When a call is made to the WebMethod (PageMethod), it first fetches the records from the database and populates a Generic list of Customer class objects and then the list is returned as a JSON object back to the Client Side function What is Generic List in C#? The Generic List in C# is a collection class which is present in System.Collections.Generic namespace. The List Collection class is one of the most widely used generic collection classes in real-time applications. This Generic List collection class represents a strongly typed list of objects which can be accessed by.

c# object is in object list; c# join strings with comma; jobject c# get value by key; c# listview add item; c# add list to list; C# get column of 2d array; sorting a list of objects in c#; linq c# object except two lists; unity array c#; find items in array c#; c# create dynamic json; arraylist in C#; c# array of objects C# Task Return Value with Examples. In this article, I am going to discuss C# Task return value in detail. Please read our previous article where we discussed how to create and use the task object in C# in different ways. At the end of this article, you will understand How to Return a Value from a Task in C# with examples C# List Sort method. The Sort method sorts the elements or a portion of the elements in the list. The method has four overloads: Sort (Comparison<T>) - Sorts the elements in the entire List<T> using the specified Comparison<T>. Sort (Int32, Int32, IComparer<T>) - Sorts the elements in a range of elements in List<T> using the specified comparer

Hi, I want to compare two Lists of objects (wich contains a list of objects) to see if they are equals . I tried these solutions but it does not return the correct result. * List1.Where(n => !List2.Contains(n)); * var res = List1.Except(List2); * var v = from x in List1 · Do the two lists contain the same instances of the objects? If not the equals. Convert Serialize List Object to JSON String in C# ASP.NET. Today, We want to share with you Convert Serialize List Object to JSON String in C# ASP.NET. In this post we will show you c# - Converting list of objects to json array, hear for Convert List Object to JSON String in C# with example we will give you demo and example for implement

C# List - forEach. When you say for-each in the context of C# List, there are two different ways, namely forEach statement and ForEach() method. forEach statement is a C# generic statement which you can use to iterate over elements of a List. Also, there is a ForEach() method that a List class implements in C# Examples. The following code demonstrates the Sort and Sort method overloads on a simple business object. Calling the Sort method results in the use of the default comparer for the Part type, and the Sort method is implemented using an anonymous method.. using System; using System.Collections.Generic; // Simple business object. A PartId is used to identify the type of part // but the part name. A typical C# program creates many objects, which as you know, interact by invoking methods. We can Create objects in C# in the following ways: 1) Using the 'new' operator: A class is a reference type and at the run time, any object of the reference type is assigned a null value unless it is declared using the new operator Insert: - Insert one new object into IList collection to specific location. Remove: - Remove the first occurrence of a specific object from the IList. RemoveAt: - To remove item at particular object from IList. Properties of IList. Few popular property of IList interface is given below. Count:- It will return number of object in List by the programmers in order to fetch the detailed information about the object at the time of compilation or sometimes at the time of runtime execution of the program. The type of value returned depends on the type of variable or object that is required at the time of execution or compilation

Several times, we want to post list of model object from view to controller while HttpPost. Many developers try to get the list of data through an array. But I'll tell you without using array also, we can get those list of model objects in a simpler way. Let's go step by step. Create an ASP.NET MVC 4 application Introduction to List in C#. List in C# plays a very important role in data storage and retrieval. Following are some important points on the generic list ( List<T> ) in C#: List< T > is a strongly typed list of objects where T represents the type of objects in the list. It is present under Collections. Generic namespace Once you have a type, you can call the GetProperties method to return a list of PropertyInfo objects representing the available properties of the type. Several methods, including GetProperties , accept an argument of BindingFlags , these flags allow you to define the type of information return, such as public members or instance members

How To Return Different Types Of Objects In C# Based On A

If I stringily the list of employees and return Json(new {Response = myStringifiedListOfEmployees}); then I can get the value from my jQuery, but this isn't what I want to do. Reply kshyj IS303 C# Creating a List of Objects Return JSON from C# Azure function. by Armin Reiter. on May 15, 2017. In this blog post I'll build a simple C# Azure function that returns an object as JSON. That's useful if you want to build a simple API or if you just want to return some information in a structured format. Such a function could read data from an on-premise. LINQ with C# Objects, Collections and Arrays. Language integrated query (LINQ) in .NET 3.5 provides querying capabilities to Object Oriented programming languages like C# or VB.NET. This integration of querying capabilities allows compile time checking of query expressions as well as intellisence support from IDE's using the reflection Dim user = JsonConvert.DeserializeObject (Of List (Of userdetails)) (strmsg) If you want complete example to implement serialization and deserialization for JSON data create new web application and open your Default.aspx page and write the code like as shown below. JSON Serialization and Deserialization in Asp.Net

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c# - Best Practices Returning Read-Only Object - Software

Description. You can get distinct class objects from the list of objects by using Distinct method if the class is C# .NET build-in class like string and int.But when you use Distinct with list of user defined custom class object, you may not get perfect result, to achieve this you need to override Equals and GetHashCode methods.. Use of Distinct with List of Custom Class objects in C# You can't use SqlQuery<T> for custom fields.. Creates a raw SQL query that will return elements of the given generic type. The type can be any type that has properties that match the names of the columns returned from the query, or can be a simple primitive type. - MSDN But, you can use ExecuteReader to achieve that.. using (var db = new Context()) { db.Database.Connection.Open(); var cmd = db. C# Split String into List. Generally, the split method in c# will return the result as a string array. If we want to return a result as a list, then we can convert a string array to a list using the List object. Following is the example to return the split method result as a list in the c# programming language

FluentResults. FluentResults is a lightweight .NET library developed to solve a common problem. It returns an object indicating success or failure of an operation instead of throwing/using exceptions XML to Object. We need to pass the stream of the read XML. The return type will be assigned to the var OR object. Here I have used the Object as an assignment type. Either you could use the var as well. The StreamReader reads the given XML to deserialize the XML back to the class object list So, we only need to change line 26, to pass in the Object property of the mock object. This is the object that will be used inside the CreateNewPlayer function, during this unit test. The power of Moq is that you can configure your mock object to return any results you want Introduction to C# Programming. Learn the fundamentals of computer programming with the new C# programming language. This course starts with programming fundamentals: input/output operations, decision making, and looping. Then, you will explore the many benefits of object-oriented programming, with plenty of vivid, real-life examples // this will return the first correct answer, // or throw an exception if there are no correct answers var correct = answers.First(a => a.Correct); // this will return the first correct answer, // or null if there are no correct answers var correct = answers.FirstOrDefault(a => a.Correct); // this will return a list containing all answers which are correct, // or an empty list if there are no.

C# How to get all elements of a List that match the

  1. g language with examples. C# Return Statement Example. Following is the example of using a return statement in the c# program
  2. I am using entity framework to get a IEnumerable<CustomersEntity>, and I need to cast this to a IEnumerable<CustomerBO> to display it in some view.I know how to do cast a IEnumerable<T1> to a IEnumerable<T2>; but in this case, who will be in charge of it ?I thought CustomerBO could do it, but is it correct for an object return a list of itself ? or have I to write a layer with only one function
  3. In c#, List is a generic type of collection, so it will allow storing only strongly typed objects, i.e., elements of the same data type.The size of the list will vary dynamically based on our application requirements, like adding or removing elements from the list. In c#, the list is same as an ArrayList, but the only difference is ArrayList is a non-generic type of collection, so it will.
  4. Re: C# LINQ: How to select multiple field and return list Feb 13, 2017 01:01 PM | ehsansajjad465 | LINK As you are fetching data using Linq from the database, so the type of the variable would be IQueryable<> , and you can materialize the reuslt in to a List<> by forcing the query to be executed and results to be brought in the memory by.
  5. To return two objects, the action's result is Json, but I'm using new {} to return an anonymous object: C#. return Json (new {}); I simply create new objects by supplying a name and a value for the object: EnvironmentVariables = ( from p in Environment .GetEnvironmentVariables ().Cast< DictionaryEntry > () select new TextValue() {

This article describes how to convert Data Table to List of Objects. In following code, you can simply convert DataTable to object type List in C#. Firstly, return null; } } } Then create a sample class for filling datatable to list ( I created. Oleg Subachev. You should use object and not dynamic, because Activator.CreateInstance() returns object.Moreover, dynamic defeats compile time type checking. Your code needs reflection to use the COM object, thus, it's only good for .NET COM objects, which is not the case for Outlook (as far as I know) Converting JSON Objects into C# List<> The problem I have is basically to fix some weird data structure coming from a data provider, which I'm sure there's some background story on why the structure is that way, into a reasonable structure that I can later on map into a model or entity more easily dot net perls. List, initialize. A C# List can be initialized in many ways. Each element can be added in a loop with the Add method. A special initializer syntax form can be used. List. Syntax notes. With this initializer syntax, objects inside the List can be initialized. Performance is similar in any initialization syntax, but some.

Seems like a hack to communicate between classes without designing in proper channels for sending Person objects around. \$\endgroup\$ - Alexander Apr 9 '17 at 3:40 \$\begingroup\$ Also, persons would be a lot more appropriately modelled by a Dictionary<int, Person> that maps Person id s to Person objects \$\endgroup\$ - Alexander Apr 9 '17. The declaration of an ArrayList is provided below. An array list is created with the help of the ArrayList Datatype. The new keyword is used to create an object of an ArrayList. The object is then assigned to the variable a1. So now the variable a1 will be used to access the different elements of the array list c# List does not return value Object reference not set to an instance of an object [duplicate] Tag: c#,list. If you want the None and '' values to appear last, you can have your key function return a tuple, so the list is sorted by the natural order of that tuple. The tuple has the form (is_none, is_empty, value); this way, the tuple.

C# return index of a object in a List - soltveit

The people array in the above example contains objects of Person class. You cannot use Array.Sort(people) because array contains objects, not primitive values.. Now, let's sort the above people array by the LastName property. For that, you need to create a class and implement IComparer interface, as shown below Here we will learn how to get object property names and values using reflection reflection in c#, vb.net with example or use reflection to get all property types and names of an object in c#, vb.net with example or reflection to get all properties of any object in c#, vb.net or Type.GetAllProperties reflection method to get all properties and values of an object in c#, vb.net with example I am creating a Web Api method that should accept a list of objects via XML or JSON and add them to a database. Here is a very basic version of what I currently have: [HttpPost] public HttpResponseMessage Put ( [FromBody]ProductAdd productAdd) { //do stuff with productadd object return Request.CreateResponse (HttpStatusCode.OK); } The model. It uses the new named tuples from C# 7 combined with an object initialiser. In very few lines you have yourself a new list of simple values. In the above I first create the list and then access each value one after another. Prior to C# 7. Prior to C# 7 you would have to write something like the following Explain the concept of Array of Objects with an Example. As we know that, we can create array of integers, floats, doubles etc. Similarly we can create array of objects. By using this array of objects, we can access methods of class with each object (which are the elements of that array)

C# - Object Initializer Syntax. C# 3.0 (.NET 3.5) introduced Object Initializer Syntax, a new way to initialize an object of a class or collection. Object initializers allow you to assign values to the fields or properties at the time of creating an object without invoking a constructor. In the above example, Student class is defined without. The first step is to create an object for the Tutorial class. Mark here that this is done by using the keyword 'new'. The 'new' keyword is used to create an object from a class in C#. The object is then assigned to the pTutor variable. The method SetTutorial is then called. The parameters of 1 and .Net are passed to the SetTutorial method

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C# Method returning an object - GeeksforGeek

C# List ExamplesCreate a new List and add elements to it. Loop over its elements with for and foreach. This method accepts a Predicate. If the Predicate returns true for each element in the List, TrueForAll() will also return true. And TrueForAll() The List is an additional object—performance is affected In c#, the Foreach loop is useful to loop through each item in an array or collection object to execute the block of statements repeatedly. Generally, in c# Foreach loop will work with the collection objects such as an array, list, etc., to execute the block of statements for each element in the array or collection. After completing iterating through each element in the collection, control. c# split a string and return list; c# string array to string; how to get the last element in an array in c#; c# join string array; convert string to array c#; c# build string out of list of strings; convert json to list object c#; c# object list contaion parameters; c# get class name by type; c# dictionary with multiple values; remove. One Jump Ahead. So here's a basic problem with converting from DataSet, DataTable, and DataRow objects to C# classes: we don't know at compile time what columns and tables exist in the set, so mapping solutions like AutoMapper won't work for this scenario. Our mapping system will have to assume what columns exist. But, in order to make it more reusable, we will make the mapping system return. What we call a C# list throughout this post is actually the List<T> class from the .Net BCL?(Base Class Library), which lives in the System.Collections.Generic namespace. The Microsoft Developer Network (MSDN) documentation says this about the list class: [It] represents a strongly typed list of objects that can be accessed by index

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List<T>.Find(Predicate<T>) Method (System.Collections ..

Classes and Objects. You learned from the previous chapter that C# is an object-oriented programming language. Everything in C# is associated with classes and objects, along with its attributes and methods. For example: in real life, a car is an object. The car has attributes, such as weight and color, and methods, such as drive and brake If you've ever wanted to get all of the children attached to a Unity GameObject and turn them into an array, there is a simple way to do it. The following code gets the jobs done, written in C#. Transform[] allChildren = GetComponentsInChildren<Transform>(); foreach (Transform child in allChildren) { child.gameObject.SetActive(false); First, IsValid (obj) may return true on null, whereas Validate (obj) has a special check for null. I would rewrite IsValid this way: public bool IsValid (T obj) { bool anyErrors = Validate (obj).Any (); return !anyErrors; } Second, your regex replacement might produce odd results in certain cases Arrays are used to store multiple values in a single variable, instead of declaring separate variables for each value. To declare an array, define the variable type with square brackets: string[] cars; We have now declared a variable that holds an array of strings. To insert values to it, we can use an array literal - place the values in a. In my previous article, I have explained few ways to convert list into datatable using C#, now in this article, I will explain various ways to convert datatable into List using C# in ASP.NET.. Suppose here is the our class Object. public class Category { public int Id { get; set; } public string CategoryName { get; set; } public bool IsActive { get; set; }

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[Solved] How To write a generic class in C# to return a

Introduction to Convert Object to JSON C#. The current state of the object must be obtained to store it or to retrieve it later and this should be considered when coding, custom code is added to output the state of the object and this is called converting object to Json string in C# and coding must be done for each and every property of the object depending on the type of knowledge we have on. 2. list.Add (new MyStruct (10)); list.Add (new MyStruct (20)); If I try to modify any element in this list, that is when things become interesting. 1. list [0].m_age = 30; The compiler starts its blaring sirens. Error: Cannot modify the return value of System.Collections.Generic.List<MyStruct>.this [int]' because it is not a variable. This.

Return List from SqlDataReader in ASP

Re: Call webapi return list of object but can not cast to base type of object? Mar 16, 2017 02:49 PM. | Tuan_Tu | LINK. Hi PatriceSc, I add this code in WebApiConfig.cs like following code: public static class WebApiConfig { public static void Register(HttpConfiguration config) { // Web API configuration and services config.Formatters. Return anonymous type from C# method. One of the new features introduced in C# 3.0 is Anonymous Types. Anonymous types provide a convenient way to encapsulate a set of read-only properties into a single object without having to explicitly define a type first. The type name is generated by the compiler and is not available at the source code level Foreach over IEnumerable with Yield Return Implementation. Implementing IEnumerable using yield return statement is super easy. Create a method or a property with IEnumerable as the return type. Then somewhere in the method call yield return for each value you intent to have in the collection Each key-value pair in the JSON object is separated by a comma. Recommended Articles. This is a guide to C# Create JSON Object. Here we also discuss the Introduction and how we can create a json object in c#? along with different examples and its code implementation. You may also have a look at the following articles to learn more - C#. MethodInfo.Invoke (Object, Object []) has the following parameters. obj - The object on which to invoke the method or constructor. If a method is static, this argument is ignored. If a constructor is static, this argument must be null or an instance of the class that defines the constructor. parameters - An argument list for the invoked method.

C# - ArrayList Class. It represents an ordered collection of an object that can be indexed individually. It is basically an alternative to an array. However, unlike array you can add and remove items from a list at a specified position using an index and the array resizes itself automatically Today, we'll talk about the new C# 9 feature, Records, and whether or not they can be used as DDD value objects. 1. C# 9 Records. C# 9's Records is a nice feature where the compiler automatically generates a whole bunch of useful boilerplate code for you. For example, for a record like this The AutoMapper in C# is a mapper between two objects. That is AutoMapper is an object-object mapper. That is AutoMapper is an object-object mapper. It maps the properties of two different objects by transforming the input object of one type to the output object of another type Questions: I have a Person object with a Nullable DateOfBirth property. Is there a way to use LINQ to query a list of Person objects for the one with the earliest/smallest DateOfBirth value. Here's what I started with: var firstBornDate = People.Min(p => p.DateOfBirth.GetValueOrDefault(DateTime.MaxValue)); Null DateOfBirth values are set to DateTime.MaxValue in order to rule. I want to, pass the list of objects, from view to the controller's action. My aim is, i will display, the list of all product's details. The user can able edit any data (even all the data). So after editing, i want to post, entire list of the object, to controller's action, where i will decide something to continue on. My sample code is:-