Solve real coding problems
There are four ways to add items to a list: I’ll show examples of all of these methods for adding to a list. Append items with List.Add() You can use List.Add() to append an item to the end of the list. Here’s an example: This outputs the list’s contents: Initialize a list with items You … Read more
The simplest way to convert an array to a list is with the ToList() Linq method: This outputs the following: Besides using ToList(), you can also use the list constructor or AddRange(). Before I show those, I’ll explain why you’d want to use these special methods instead of just adding items individually to a new … Read more
If you try to add/remove items from a collection while it’s being looped over in a foreach loop (enumerated), then you’ll get the following exception: System.InvalidOperationException: Collection was modified; enumeration operation may not execute.at System.Collections.Generic.List`1.Enumerator.MoveNext() This error can happen in two scenarios: The solution to this problem depends on which scenario you’re in. In this … Read more
A CheckedListBox allows the user to check one or more checkboxes. Sometimes you’ll want to be able to check the boxes programmatically. For example, you may want to allow the user to check or uncheck all boxes at once. Or perhaps you want to persist the values the user checked and load them later. To … Read more