c#

Sequence contains no matching element

Well, I’d expect it’s this line that’s throwing the exception: First() will throw an exception if it can’t find any matching elements. Given that you’re testing for null immediately afterwards, it sounds like you want FirstOrDefault(), which returns the default value for the element type (which is null for reference types) if no matching items are found: … Read more

Passing just a type as a parameter in C#

There are two common approaches. First, you can pass System.Type This would be called like: int val = (int)GetColumnValue(columnName, typeof(int)); The other option would be to use generics: This has the advantage of avoiding the boxing and pr

Passing just a type as a parameter in C#

There are two common approaches. First, you can pass System.Type This would be called like: int val = (int)GetColumnValue(columnName, typeof(int)); The other option would be to use generics: This has the advantage of avoiding the boxing and providing some type safety, and would be called like: int val = GetColumnValue<int>(columnName);

Member ‘‘ cannot be accessed with an instance reference

In C#, unlike VB.NET and Java, you can’t access static members with instance syntax. You should do: to refer to that property or remove the static modifier from Property1 (which is what you probably want to do). For a conceptual idea about what static is, see my other answer.

IEnumerable vs List – What to Use? How do they work?

IEnumerable describes behavior, while List is an implementation of that behavior. When you use IEnumerable, you give the compiler a chance to defer work until later, possibly optimizing along the way. If you use ToList() you force the compiler to reify the results right away. Whenever I’m “stacking” LINQ expressions, I use IEnumerable, because by … Read more

Are 2 dimensional Lists possible in c#?

Well you certainly can use a List<List<string>> where you’d then write: But why would you do that instead of building your own class to represent a track, with Track ID, Name, Artist, Album, Play Count and Skip Count properties? Then just have a List<Track>.

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 Split() function. I want to store each column into a separate array and then display it. Is it possible to … Read more

Read and parse a Json File in C#

I have spent the best part of two days “faffing” about with code samples and etc., trying to read a very large JSON file into an array in c# so I can later split it up into a 2d array for processing. The problem I was having was I could not find any examples of … Read more

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