将ObservableCollection的内容写入文本文件

Question

The goal of this question is to find out a way to obtain specific contents of an ObservableCollection ( strings to be specific), and write them to a text file.

This collection is structured by using nodes because it is used to implement a TreeView . With that being said I am currently trying to obtain the child values of a parent node like so:

//I am currently getting an InvalidOperationException -- Sequence contains no matching element
var Node = Collection.GetAllChildren(x => x.Children).Distinct().ToList().First(x => x.DisplayName == Name);

In order to write to the file I am using this File. method: File.WriteAllLines() . It is my understanding that this method takes the FileName, and then an IEnumerable (a List , etc.). Does ObservableCollection contain a method that is IEnumberable compatible or do I need to add the contents to a List ?

Right now I am trying this for the write to file line:

File.WriteAllLines(FileName, new ObservableCollection<string> { ViewModel.Data.ToList() });

How can I correct these two detrimental parts of my code? What is the correct way to get the information I need, and then add it to the file?

Update: These are the current errors that I receive on the above^ line of code. If I am implementing this correctly (which I am, based on the answers), why am I receiving these compile errors? (note: type has been switched to string )

Update 2: I've updated the argument to be written to the file. Data is an ObservableCollection<ViewModel> .

Answer 1

Yes, an overload of File.WriteAllLines takes IEnumerable<string> . ObservableCollection<string> implements IEnumerable<string> , so things should work.

Just Type should be string :

File.WriteAllLines(FileName, new ObservableCollection<Type> ( NodeName.ToList() ));

Does ObservableCollection contain a method that is IEnumberable compatible

No, it implements IEnumerable.

PS As it is suggested in another answer, ObservableCollection is redundant. You may pass anything which implements IEnumerable<string> .

Answer 2

If you look at the signature of System.IO.File.WriteAllLines(), it accepts an array of strings or an IEnumerable of strings;

Try this:

File.WriteAllLines(FileName, NodeName.ToList());