icollection

Must IList be finite?

由 ☆樱花仙子☆ 提交于 2019-12-21 07:07:01
问题 Must .NET's IList be finite? Suppose I write a class FibonacciList implementing IList<BigInteger> The property Item[n] returns the nth Fibonacci number. The property IsReadOnly returns true. The methods IndexOf and Contains we can implement easily enough because the Fibonacci sequence is increasing - to test if the number m is Fibonacci, we need only to compute the finite sequence of Fibonacci numbers up to m. The method GetEnumerator() doing the right thing We've now implemented all the

how to pass one-to-many from controller to view in mvc4

由 孤街浪徒 提交于 2019-12-20 04:51:29
问题 Ok so this would be after changes that you guys helped me with , im assuming im getting a syntax error somewhere View @model OilNGasWeb.ModelData.Clients @{ ViewBag.Title = "Index"; } <h2>County's for </h2> <p> @Html.ActionLink("Create New", "Create",new { id = Model.ClientID },null) </p> <table> <tr> <th> @Html.DisplayNameFor(model => model.County) </th> <th> @Html.DisplayNameFor(model => model.Note) </th> <th> @Html.DisplayNameFor(model => model.Comment) </th> </tr> @foreach (var item in

Replacing an element in ICollection

由 隐身守侯 提交于 2019-12-20 02:32:34
问题 Suppose I have an ICollection<SomeClass> . I have the following two variables: SomeClass old; SomeClass new; How can I achieve something like the following using an ICollection<SomeClass> ? // old is guaranteed to be inside collection collection.Replace(old, new); 回答1: There is no black magic here: ICollection<T> is not ordered and only provides Add / Remove methods. Your only solution would be to check if the actual implementation is something more , such as IList<T> : public static void

T in class? AddRange ICollection?

由 帅比萌擦擦* 提交于 2019-12-19 06:44:26
问题 I try to do static class, add to icollection but i got some issues i cant seem to overcome. that is how i get so i can pass a ICollection in the method? cause T is that say it can not be resolved. and then i wonder is there a way to do AddRange on icollection? i was thinking of something like this but maby i am way out of my mind with it? public static ICollection<T> add(this IEnumerable<T> list) { ICollection<T> collection = null; return collection.AddRange(list); } 回答1: No, ICollection<T>

Difference between IEnumerable and IEnumerable<T>?

由 有些话、适合烂在心里 提交于 2019-12-17 23:03:23
问题 What is the difference between IEnumerable and IEnumerable<T> ? I've seen many framework classes implementing both these interfaces, therefore I would like to know what advantages one get by implementing both? Please have a look how they've been defined: public interface IEnumerable { [DispId(-4)] IEnumerator GetEnumerator(); } public interface IEnumerable<T> : IEnumerable { IEnumerator<T> GetEnumerator(); } As we see, IEnumerable<T> derives from IEnumerable , that means whatever IEnumerable

Using a list as a data source for DataGridView

由 柔情痞子 提交于 2019-12-17 07:26:07
问题 I've extracted the setting names and their respective values out of a configuration file into an ordered dictionary. The dictionary contains keys and values which are of the ICollection class. I want to bind that data and display it in a DataGridView. I've tried copying the strings to arrays and displaying those arrays, but when I ran the program the columns were blank and it did not seem to be binded at all. I've also attempted to set the DataGridView source directly to one the ordered

Using LINQ with classes implementing non-generic ICollection

由 旧街凉风 提交于 2019-12-13 12:25:32
问题 I wanted to run a LINQ query against a MatchCollection object but found this wasn't possible as it doesn't implement ICollection<T> , just ICollection . What is the best option for using LINQ with non-generic collections, both in terms of code conciseness but also performance and memory usage? (If interested, here is the non-LINQuified code:) MatchCollection fieldValues = Regex.Matches(fieldValue, @"(?<id>\d+);#(?<text>[^;|^$]+)"); foreach (Match m in fieldValues) { if (m.Groups["text"].Value

最全数据结构详述: List VS IEnumerable VS IQueryable VS ICo

由 老子叫甜甜 提交于 2019-12-13 11:54:41
【推荐】2019 Java 开发者跳槽指南.pdf(吐血整理) >>> 本文对常用的数据结构详述：Array, ArrayList，List，IList，ICollection, Stack, Queue, HashTable, Dictionary, IQueryable, IEnumerable。 Collection（集合） Collection是数据记录集合， 编写代码过程中，常常需要合适的容器保存临时数据，方便修改和查找，如何选取合适的数据容器，关键在于将执行的数据操作以及数据记录是否大量。 Array（数组） 特征 1. 固定大小，数组的大小是初始化时决定无法修改的数值。 2. 强类型，存储数据元素类型必须在初始化时指定，因此在运行时，不需要耗费额外的时间来定义数组类型，能够大大提升运行效率。 3. 可使用Foreach关键字实现数组迭代和查找。 因为数组大小是固定的，且是强类型数据结构，因此在运行时只占用很少的内存，运行时效率很高。 1: //It is obvious that strArray is 2: //1. string --> Strongly Type 3: //2. Sized=10 --> Fixed Size 4: 5: string [] strArray = new string [10]; 6: 7: for ( int i = 0; i

The property Count from ICollection<T> is still around for backward compatibility?

由 倾然丶 夕夏残阳落幕 提交于 2019-12-13 10:37:58
问题 Previous Context To understand what I'm questioning, see first the question "Why does .Count work without parentheses?" In that question is discussed, Why exists Count (property) and Count() (method) in classes that implements ICollection<T> . that question was answered satisfactorily. But below the answer in a comment, another question was raised by finoutlook: The question The property Count is still around (in later .Net versions to LINq technology) for backward compatibility? 回答1: No, it

How should I get the length of an IEnumerable? [duplicate]

由 岁酱吖の 提交于 2019-12-12 12:33:50
问题 This question already has answers here : Count the items from a IEnumerable<T> without iterating? (18 answers) Closed last year . I was writing some code, and went to get the length of an IEnumerable. When I wrote myEnumerable.Count() , to my surprise, it did not compile. After reading Difference between IEnumerable Count() and Length, I realized that it was actually Linq that was giving me the extension method. Using .Length does not compile for me either. I am on an older version of C#, so
订阅 icollection