C# Action in Foreach

Question

fMethod is an Action<Fruit>.

But when fMethod is called, the parameter is always the last entry of _Fruits.
How to solve this?

foreach(Fruit f in _Fruits)
{
   field.Add(new Element(f.ToString(),delegate{fMethod(f);}));
}

Answer 1

This is a well-known problem of using a modified clause in a call that creates a delegate. Adding a temporary variable should solve it:

foreach(Fruit f in _Fruits)
{
    Fruit tmp = f;
    field.Add(new Element(f.ToString(),delegate{fMethod(tmp);}));
}

This problem is fixed in C# 5 (see Eric Lippert's blog).

Answer 2

Try using a temp variable.

foreach(Fruit f in _Fruits)
{
   var temp = f;
   field.Add(new Element(temp.ToString(),delegate{fMethod(temp);}));
}