Create a C# Method to Generate Auto Increment Id

C# Class Auto increment ID

This will do the trick, and operate in a nice threadsafe way. Of course it is up to you to dispose the robots yourself, etc. Obviously it won't be efficient for a large number of robots, but there are tons of ways to deal with that.

  public class Robot : IDisposable
  {
    private static List<bool> UsedCounter = new List<bool>();
    private static object Lock = new object();

    public int ID { get; private set; }

    public Robot()
    {

      lock (Lock)
      {
        int nextIndex = GetAvailableIndex();
        if (nextIndex == -1)
        {
          nextIndex = UsedCounter.Count;
          UsedCounter.Add(true);
        }

        ID = nextIndex;
      }
    }

    public void Dispose()
    {
      lock (Lock)
      {
        UsedCounter[ID] = false;
      }
    }


    private int GetAvailableIndex()
    {
      for (int i = 0; i < UsedCounter.Count; i++)
      {
        if (UsedCounter[i] == false)
        {
          return i;
        }
      }

      // Nothing available.
      return -1;
    }

And some test code for good measure.

[Test]
public void CanUseRobots()
{

  Robot robot1 = new Robot();
  Robot robot2 = new Robot();
  Robot robot3 = new Robot();

  Assert.AreEqual(0, robot1.ID);
  Assert.AreEqual(1, robot2.ID);
  Assert.AreEqual(2, robot3.ID);

  int expected = robot2.ID;
  robot2.Dispose();

  Robot robot4 = new Robot();
  Assert.AreEqual(expected, robot4.ID);
}

How to generate and auto increment Id with Entity Framework

This is a guess :)

Is it because the ID is a string? What happens if you change it to int?

I mean:

 public int Id { get; set; }

How can I manually set an ID for an AUTOINCREMENT column using a designer-generated DataTable?

You'll have to either use an auto-incrementing value, or set it yourself. There is no option to do both.

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