c# Generic List

Question

I m populating data for different entities into set of lists using generic lists as follows :

List<Foo> foos ..
List<Bar> bars ..

I need to write these lists to a file, i do have a util method to get the values of properties etc. using reflection.

What i want to do is: using a single method to write these into files such as:

 void writeToFile(a generic list)
 {
  //Which i will write to file here.
 }

How can i do this?

I want to be able to call :

writeToFile(bars);
writeToFile(foos);

Answer 1

void writeToFile<T>(List<T> list)
{
    // Do the writing
}

Answer 2

You can use generics to allow the caller to specify the expected type the list contains.

void writeToFile<T>(IList<T> list)
{
    ...
}

Answer 3

Probably something like...

private void WriteToFile<T>(
  IEnumerable<T> elementsToWrite,
  Func<T, string> convertElementToString) {
  foreach (var element in elementsToWrite)
  {
    var stringRepresentation = convertElementToString(element);
    // do whatever other list-stuff you need to do
  }
}

// called like so...
WriteToFile(listOfFoo, foo => foo.FP1 + ", " + foo.FP2 + " = " foo.FP3);
WriteToFile(listOfBar, bar => bar.BP1 +"/"+ bar.BP2 + "[@x='" + bar.BP3 + "']");

...or you could try something like...

private void WriteToFile<T>(
  IEnumerable<T> elementsToWrite,
  Action<T, TextWriter> writeElement) {
  var writer = ...;

  foreach (var element in elementsToWrite)
  {
    // do whatever you do before you write an element
    writeElement(element, writer);
    // do whatever you do after you write an element
  }
}

// called like so...
WriteToFile(listOfFoo, (foo, writer) =>
  writer.Write("{0}, {1} = {2}", foo.FP1, foo.FP2, foo.FP3));
WriteToFile(listOfBar, (bar, writer) =>
  writer.Write("{0}/{1}[@x='{2}']", bar.BP1, bar.BP2, bar.BP3));

...or whatever... you get the idea.

Answer 4

You should look into the topic of serialization. There is are some articles out there about dealing with generic types.