50,724 questions
574
votes
12
answers
383k
views
HashSet vs. List performance
It's clear that a search performance of the generic HashSet<T> class is higher than of the generic List<T> class. Just compare the hash-based key with the linear approach in the List<T&...
- 15.8k
274
votes
12
answers
249k
views
How to check for file lock? [duplicate]
Is there any way to check whether a file is locked without using a try/catch block?
Right now, the only way I know of is to just open the file and catch any System.IO.IOException.
- 36.9k
266
votes
9
answers
239k
views
Linq to Entities - SQL "IN" clause
In T-SQL you could have a query like:
SELECT * FROM Users WHERE User_Rights IN ("Admin", "User", "Limited")
How would you replicate that in a LINQ to Entities query? Is it even possible?
- 17.6k
213
votes
6
answers
201k
views
How to handle AccessViolationException
I am using a COM object (MODI) from within my .net application. The method I am calling throws a System.AccessViolationException, which is intercepted by Visual Studio. The odd thing is that I have ...
- 46.8k
635
votes
29
answers
525k
views
Copy the entire contents of a directory in C#
I want to copy the entire contents of a directory from one location to another in C#.
There doesn't appear to be a way to do this using System.IO classes without lots of recursion.
There is a method ...
- 157k
295
votes
8
answers
81k
views
TransactionScope automatically escalating to MSDTC on some machines?
In our project we're using TransactionScope's to ensure our data access layer performs it's actions in a transaction. We're aiming to not require the MSDTC service to be enabled on our end-user's ...
- 5,652
118
votes
14
answers
74k
views
Random row from Linq to Sql
What is the best (and fastest) way to retrieve a random row using Linq to SQL when I have a condition, e.g. some field must be true?
- 13k
1733
votes
30
answers
542k
views
What is the difference between const and readonly in C#?
What is the difference between const and readonly in C#?
When would you use one over the other?
- 358k
364
votes
19
answers
601k
views
Get URL parameters from a string in .NET
I've got a string in .NET which is actually a URL. I want an easy way to get the value from a particular parameter.
Normally, I'd just use Request.Params["theThingIWant"], but this string ...
- 12.8k
238
votes
24
answers
229k
views
String vs. StringBuilder
I understand the difference between String and StringBuilder (StringBuilder being mutable) but is there a large performance difference between the two?
The program I’m working on has a lot of case ...
- 2,411
968
votes
14
answers
810k
views
When to use .First and when to use .FirstOrDefault with LINQ?
I've searched around and haven't really found a clear answer as to when you'd want to use .First and when you'd want to use .FirstOrDefault with LINQ.
When would you want to use .First? Only when you'...
- 38.5k
514
votes
32
answers
216k
views
How do you unit test private methods?
I'm building a class library that will have some public & private methods. I want to be able to unit test the private methods (mostly while developing, but also it could be useful for future ...
- 30.1k
455
votes
22
answers
1.3m
views
Reading CSV file and storing values into an array
I am trying to read a *.csv-file.
The *.csv-file consist of two columns separated by semicolon (";").
I am able to read the *.csv-file using StreamReader and able to separate each line by using the ...
- 4,611
252
votes
9
answers
327k
views
Show/Hide the console window of a C# console application
I googled around for information on how to hide one’s own console window. Amazingly, the only solutions I could find were hacky solutions that involved FindWindow() to find the console window by its ...
- 66.8k
171
votes
4
answers
66k
views
Should I avoid 'async void' event handlers?
I know it is considered generally a bad idea to use fire-and-forget async void methods to start tasks, because there is no track of the pending task and it is tricky to handle exceptions which might ...
- 10.9k
88
votes
8
answers
96k
views
What is the best choice for .NET inter-process communication? [closed]
Should I use Named Pipes, or .NET Remoting to communicate with a running process on my machine?
- 2,356
497
votes
16
answers
79k
views
Is DateTime.Now the best way to measure a function's performance? [closed]
I need to find a bottleneck and need to accurately as possible measure time.
Is the following code snippet the best way to measure the performance?
DateTime startTime = DateTime.Now;
// Some ...
- 73.4k
447
votes
3
answers
420k
views
Task vs Thread differences [duplicate]
There are two classes available in .NET: Task and Thread.
What is the difference between those classes?
When is it better to use Thread over Task (and vice-versa)?
- 12.1k
386
votes
7
answers
268k
views
HttpClient.GetAsync(...) never returns when using await/async
Edit: This question looks like it might be the same problem, but has no responses...
Edit: In test case 5 the task appears to be stuck in WaitingForActivation state.
I've encountered some odd ...
- 5,800
253
votes
40
answers
719k
views
Invalid postback or callback argument. Event validation is enabled using '<pages enableEventValidation="true"/>'
I am getting the following error when I post back a page from the client-side. I have JavaScript code that modifies an asp:ListBox on the client side.
How do we fix this?
Error details below:
...
140
votes
8
answers
93k
views
Change default app.config at runtime
I have the following problem:
We have an application that loads modules (add ons). These modules might need entries in the app.config (e.g. WCF configuration). Because the modules are loaded ...
- 175k
44
votes
3
answers
30k
views
Single objects still limited to 2 GB in size in CLR 4.0?
As I understand it there's a 2 GB limit on single instances in .NET. I haven't paid a lot of attention to that since I have mainly worked on 32 bit OS so far. On 32 but it is more or less an ...
- 117k
429
votes
7
answers
450k
views
Calculate MD5 checksum for a file
I'm using iTextSharp to read the text from a PDF file. However, there are times I cannot extract text, because the PDF file is only containing images. I download the same PDF files everyday, and I ...
- 8,342
319
votes
20
answers
395k
views
Get the correct week number of a given date
I have Googled a lot and found a lot of solutions, but none of them give me the correct week number for the 2012-12-31. Even the example on MSDN (link) fails.
2012-12-31 is Monday, therefore it ...
- 40.7k
295
votes
5
answers
79k
views
Why does .NET use banker's rounding as default?
According to the documentation, the decimal.Round method uses a round-to-even algorithm which is not common for most applications. So I always end up writing a custom function to do the more natural ...
- 1.0m