Develop Reference

ListBox sorting by files creation time

My listBox1 is filled with names of txt files. It is sorting them automatically alphabetically. But I need to sort these files by creation time, from the newest to the oldest. Can someone help me?

you are not giving us much to go on :P
But I am going to give it my best shot to help you. Because I do not know how you have populated the List (by hand, or with code) I cant really guide you there.
But lets say you did it by code. The following snippet I typed might help you find what you need
//array of file names (these need to be paths to files, so if you do not prefix it with ./path/ or anything, then the executable needs to be in the same folder)
//If you are debugging, make sure the paths are correct if you expect them to be in the same folder, it should then be in the debug folder.
//If you included some test files in the solution and want them copied to your debug folder. Click on them, go to the properties pane, and set build action to content, and one of the other properties should read copy of newer instead of never copy
var fileNames = new string[]{"1.txt", "2.txt", "3.txt"};
var fileInfos = fileNames.Select(f => new FileInfo(f));
var orderedFileInfos = fileInfos.OrderBy(f => f.CreationTime);
orderedFileInfos is now a list of type FileInfo ordered by ascending on their creationtime.
This is what you can use to populate your ListBox
I hope i helped you progress in your project.

Creating Local Cache like memory

As a part of a project I'm working on, I need to implement a cache like mechanism.
My cache is composed of 3 main things: Dictionary, List, File.
where the Dictionary needs to save the last 1000 items.
the list saves everything it can with its given memory
and at last we have the File to hold all items.
when I'd like to search from a range og items I need to look for like that:
Dictionary->List->File.
searching the file should be about 0%, since efficiency is required.
I'm trying to think about a proper function to search those last items (usually they are the ones that I need to extract)
for example one can request for items 1 to 1200 (searching the dictionary and then the list) and so on...
What is the best way to do this kind of search?

C#-Replacing Sharepoint list data nightly

I have a Sharepoint list on a site that I want to update nightly from a SQL server DB, preferably using C#. Here is the catch, I do not know if any records were removed, added, or if any field in any record has been updated. I would believe then the simplest thing to do is remove the data from the list and then replace it with the new list data. But is there any simple way to do this? I would hate to remove 3000+ items line by line from the list and then add the 3000+ records one at a time.

Its up to your environment. If you not that much load on the systems in the night, i would prefer one of the following ways:
1) Build a timerjob, delete the list (not the items one by one, cause this is slow), recreate the list and import the items from the db. When we are talking about 3.000 - 5.000 Elements, this is not that much and i think done under 10 Minutes.
2) Loop through the sharepoint list with the items and check field by field if it was updated within the db and if yes, update it.
I would preferr to delete the list and import the complete table, cause we are talking about not that much data.
Another way, which is a good idea, is to use BCS or BDC. Then you would have the data always in place and synched with the db. Look at
https://msdn.microsoft.com/en-us/library/office/jj163782.aspx
https://msdn.microsoft.com/de-de/library/ee231515(v=vs.110).aspx

Unfortunately there is no "easy" and/or elegant way to delete all the items in a list, like the delete statement in SQL. You can either delete the entire list and recreate it if the list can be easily created from a list definition or, if your concern is performance, since SP 2007 the SPWeb Class has a method called ProcessBatchData. You can use it to batch process commands to avoid the performance penalty of issuing 6000 separate commands to the server. However, it still requires you to pass an ugly XML that contains a list of all the items to be deleted or added.

The ideal way is to enumerate all the rows from the database and see if each row already exists in the SharePoint list using a primary field value. If it already exists, simply update them[1]. Otherwise you can add a new item.
[1] - Optionally, while updating them we can compare the list item field values with database column values. Only if there is a change in any of the field, update it. Otherwise skip it.

Not able to copy multiple SPFieldLookupValue from one list to another

I am having a scenario where I am required to copy the SharePoint list items from one list to another it includes various types of fields such as text, lookup and people group.
I am trying to copy the look-up field from one list to another using the following piece of code but what it does is it copies only the last value in the loop into the other list column but I want all the entire set items copied from one list to another.
foreach (SPFieldLookupValue value in values)
{
targetItem["Hiring_x0020_Manager"] = new SPFieldLookupValue(value.ToString());
}
Is there anyway to copy the entire set of items from one list to another separately.
Also is it possible to copy SP Column type of people and look-up from one list to another using a similar code snippet.

…but what it does is it copies only the last value in the loop…
You keep overwriting the value of the destination field. Hence yes, it behaves like that.
For lookup fields that have multiple values enabled, you have to construct a new SPFieldLookupValueCollection instance and assign it to the destination field. I assume your values variable is exactly of this type. There is an extensive example in MSDN.

How to get all files from a folder in sorted order in C#.Net? [duplicate]

Is is possible to get files that is ordered same as in Windows Explorer
I know "natural sort", but it's not what I need, I need to get the file list ordered by the same attribute in Windows Explorer, for example:
If I ordered a directory by the attribute "create date", then I will get a file list as below:
name create date file size
1.txt 2012/1/1 125Kb
2.tab 2012/3/2 15Kb
3.bmp 2013/5/5 26Kb
If my windows explorer order file list with the attribute "file size", the the file list would be:
name create date file size
2.tab 2012/3/2 15Kb
3.bmp 2013/5/5 26Kb
1.txt 2012/1/1 125Kb
Could anyone help?

I think this is going to be a lot more complex than you expect. Folder settings are stored in the registry in two places:
HKCU\Software\Microsoft\Windows\Shell\BagMRU
HKCU\Software\Microsoft\Windows\Shell\Bags
The first path contains a structure which reflects the structure of the file system, and the second path contains details about those items, including a REG_BINARY value called "Sort" which records the sort order used for that folder.
See Willi Balenthin's website for details on the structure, including sample code (in Python)

Here's how to get a list of files sorted by their name:
var path = #"C:\windows"; // obviously change this to whatever you want
var files = System.IO.Directory.GetFiles (path).ToList ();
file.Sort();
And that's it!
Here's how you would do it per your given code sample:
var temperaturePressureSignalFilesList = Directory.GetFiles(TemperaturePressureSignalDirectory, "*.txt", SearchOption.TopDirectoryOnly).ToList();
temperaturePressureSignalFilesList.Sort();

using System.Linq;
DirectoryInfo info = new DirectoryInfo(""); FileInfo[] files =
info.GetFiles().OrderBy(p => p.CreationTime).ToArray(); foreach
(FileInfo file in files) {
// DO Something... }
here is the sample code for get files in directory by creation time.
You can get files by size same way.

I guess you are talking about viewing pane in Windows Explorer (it's essentially a Windows File Manager but also known under different name). Some clarification is needed. You can apply your custom sorting on various columns; moreover, you can have multiple viewing panes (windows) open sorted on different columns. Thus, the problem definition is a bit unclear.
Assuming that you know the sorting order in your viewing panes, then you can use System.IO.DirectoryInfo and derived FileSystemInfo[] objects; the latter has files.OrderBy method.
Hope this will help. My best, Alex

If you want natural sort order, you should either P/Invoke StrCmpLogicalW (http://msdn.microsoft.com/en-us/library/bb759947.aspx) or find a managed natural sort algorithm. There is no built-in natural sort in .NET Framework.

I think you cannot know which is the order in the pane (by size, name or whatever), you must read the list and then sort it the way you want or prompt the user to select a sorting attribute.
As Kenny posted Sorting Directory.GetFiles() here is an approach, anyway I still thinking there is no possibly way to know which is the sorting order that user selected in the viewing pane.

I think you would have to write a shell extension for windows explorer that captures sort events on columns and writes that metadata to disk in some structured way. You may have multiple explorer windows open so might be an idea to apply timestamp or id so you know which explorer window you are dealing with. Then in your app read that metadata to get the sort order and apply accordingly. Not easy but doable.