How to move object between dictionaries?

I have simple task where I need to check objects in one dictionary and if certain criteria met move to another. What I am asking if there is some good pattern where I can use language feature to achieve that. The straight approach is simple - use temporaty collection, first step determine canditates, second step do actual move. It is ok but it is not cool.

Current code

class Order
{
  public int ID;
  public bool IsReady;
}

Dictionary<int, Order> ActiveDictionary;
Dictionary<int, Order> ProcessedDictionary;

public Update()开发者_如何学Go
{    
 // temporary list, uncool
 List<Order> processed = new List<Order>();


 // fist step
 foreach(Order ord in ActiveDictionary)
 {
  if(ord.IsReady)
  {
    processed.Add(ord);
  }
 }

 // ok now lets move
 foreach(Order ord in processed)
 {
  ActiveDictionary.Remove(ord.ID);
  ProcessedDictionary.Add(ord.ID, ord);
 }
}

There is nothing really wrong with the code you have.

As an exercise in alternatives, you could do something like...

ProcessedDictionary = ProcessedDictionary
    .Concat(
        ActiveDictionary.Where(kvp => kvp.Value.Ready)
    )
    .ToDictionary(kvp => kvp.Key, kvp => kvp.Value);

ActiveDictionary = ActiveDictionary.Where(kvp => !kvp.Value.Ready)
    .ToDictionary(kvp => kvp.Key, kvp => kvp.Value);

if Rex M's answer is not suitable (maybe you don't want to rebuild Dictionaries on each iteartion), then as small improvement I can suggest to replace

// temporary list, uncool
List<Order> processed = new List<Order>();

// fist step
foreach(Order ord in ActiveDictionary)
{
  if(ord.IsReady)
  {
     processed.Add(ord);
  }
}

to

var processed = ActiveDictionary.Where(x=>x.Value.Ready).ToArray();

and the rest of your code would be

foreach(var item in processed)
{
   ActiveDictionary.Remove(item.Key);
   ProcessedDictionary.Add(item.Key, item.Value);
}

UPD: As Ani commented, there is another alike solution:

var processed = ActiveDictionary.Values.Where(x=>x.Ready).ToArray();

foreach(var item in processed)
{
   ActiveDictionary.Remove(item);
   ProcessedDictionary.Add(item.Id, item);
}

try this

var keys = ActiveDictionary
    .Where(kv => kv.Value.Ready)
    .Select(kv => kv.Key).ToList();
keys.ForEach(k =>
        {
            ProcessedDictionary.Add(k, ActiveDictionary[k]);
            ActiveDictionary.Remove(k);
        });