I want to monitor changes to a CollectionView but the CollectionChanged event is protected. How should I do this? Surely there must be a way to subscribe to this event - the list controls must do this somehow. I can cast SourceCollection to INotifyCollectionChanged and add an event there, but that seems unneccesarily messy. ...
Is there an easy way to obtain the average of an attribute in a collection? For instance, each user has a score. Given a collection of user(s) (@users), how can you get the average score for the group? Is there anything like @users.average(:score)? I think I came across something like this for database fields, but I need it to work f...
Here's the situation: I have a datatype C that has a one-to-many reference to Datatype P. Datatype P has an optional R reference (one to one). My attempted query was as follows (it was a count, but it will also be used to pull data) FROM C WHERE ... AND P.R.rProperty LIKE 'BLAH%'; I get a org.hibernate.QueryException: illegal atte...
This is more a gotcha I wanted to share than a question: when printing with toString(), Java will detect direct cycles in a Collection (where the Collection refers to itself), but not indirect cycles (where a Collection refers to another Collection which refers to the first one - or with more steps). import java.util.*; public class Sh...
Hi there, I want to write a map-like object type in PL/SQL. What I mean is a key-value-pair list, where a value can be another key-value-pair list. Simple, or so I thought. Here are the two simplified CREATE OR REPLACE TYPE TKey AS OBJECT ( name varchar2(240), value_text varchar2(2000), value_map TMap ) CREATE OR REPLACE T...
How do u collect all the checkboxes and dropdownlist items inJQuery for saving ...
I've gone through and programmed all my domain level logic to interfaces. Now I find that when I want to put data in a bean, the bean doesn't work because the Collection interfaces (Collection, List, Set, etc) do not implement Serializable. Do I need to refactor all my code to use concrete types or is there a better course of action her...
Imagine that I need to create a Collection of elements, where order could or could not matter. Effectively all I plan on doing is using the iterator. I notice most of my colleagues using an ArrayList vs LinkedHashSet/HashSet. My question is, if I know that these elements should be unique, should I be using a Set or a List? Effectively it...
I would like to know why according to this article and observable collection binds significantly faster(20 ms vs 1685ms, that's 800X faster) than a List<> collection in WPF. I looked at the internals of ObservableCollection and it uses a List as it's storage collection object(I used reflector and saw this in the constructor) public Coll...
I have 60k items that need to be checked against a 20k lookup list. Is there a collection object (like List, HashTable) that provides an exceptionly fast .Contains() method? Or will I have to write my own? In otherwords, is the default .Contains() method just scan each item or does it use a better search algorithm. foreach Record item i...
What is the best way to pick a random brush from the System.Drawing.Brushes collection in C#? ...
I have one million rows of data in .txt format. the format is very simple. For each row: user1,value1 user2,value2 user3,value3 user1,value4 ... You know what I mean. For each user, it could appear many times, or appear only once (you never know). I need to find out all the values for each user. Because user may appear randomly, I u...
How can I allow selected rows in a DataGridView (DGV) to be moved up or down. I have done this before with a ListView. Unfortunetly, for me, replacing the DGV is not an option (curses). By the way, the DGV datasource is a Generic Collection. The DGV has two buttons on the side, yes, UP & Down. Can anyone help point me in the right di...
I'm developing a 'TreeDict' class in Python. This is a basically a dict that allows you to retrieve its key-value pairs in sorted order, just like the Treemap collection class in Java. I've implemented some functionality based on the way unique indexes in relational databases can be used, e.g. functions to let you retrieve values corre...
I have some hierarchical data in a Winforms TreeView control and I need to expose it as a property so my presenter can synchronize changes to it. Just to be clear, I'm using the Passive View pattern. With most WinForm controls this is a no-brainer. The controls themselves expose their data as a system type which can easily be passed alon...
I have an ObservableCollection. I've bound it to a ListBox control and I've added SortDescriptions to the Items collection on the ListBox to make the list sort how I want. I want to resort the list at ANY point when any property changed on a child element. All my child elements implement INotifyPropertyChanged. ...
List<string> list1 = new List<string>(); list1.Add("Blah"); list1.Add("Bleh"); list1.Add("Blih"); List<string> list2 = new List<string>(); list2.Add("Ooga"); list2.Add("Booga"); list2.Add("Wooga"); Is there a method to create a third list that has {"Blah", "Bleh", "Blih", "Ooga", "Booga", "Wooga"} or, alternatively, change list1 so it...
I have a ListView bound to a Generic List collection. I need to be able to limit the number of items bound to something like 5, and show a more button in the template. I can handle the DataBinding event, and remove the last few items in the List<>, but something about that doesn't feel right. I also can't limit the list to 5 beforehan...
Similar to my other question: I have a ListView bound to a Dictionary. Then I have a nested ListView for the dictionary's value's integers. I need to limit the number of items bound to the nested list to something like 5, and show a more button in the template. I can't find a way to get the more button to work, and to correctly limit...
I have a factory that creates job objects in the form of IJob Public Interface IJobFactory Function CreateJobs(ByVal cacheTypes As CacheTypes) As IEnumerable(Of IJob) End Interface The interface IJob defines three things Public Interface IJob Sub Execute() ReadOnly Property Id() As Integer ReadOnly Property JobType() ...