每次触发事件时，在DataGridView中添加具有递增值的新行

Question

I have a table which has an ID, Name, and ActiveStatus which are set to default on a button click event. Whenever I click, it adds a new row to the datagridview but does nothing if i want to add a new row under it WITH AN INCREMENT VALUE OF PREVIOUS VALUE. Like if there is already an id with number 1 is present, it should add a new row with id = 2. or if it is empty, it should add id = 1.

   MyDatabase mydata = new MyDatabase();
   List<MyDatabase> listmydata = new List<MyDatabase>();

        mydata.id = "1";
        mydata.Name = "YO";
        mydata.ActiveStatus= true;
        listmydata.Add(mydata);
        dataGridView1.DataSource = listmydata.ToList<MyDatabase>();

//This adds only 1 new row, does nothing if we click the button again

Answer 1

Try to announce a global class variable, wich will count your new elements, wich you can use as id field in MyDatabase list.

public class Form...
{
   private int elemsCount = 0;
   public event(...)
   {
      MyDatabase mydata = new MyDatabase();
      List<MyDatabase> listmydata = new List<MyDatabase>();

      mydata.id = elemsCount.ToString();
      mydata.Name = "YO";
      mydata.ActiveStatus= true;
      listmydata.Add(mydata);
      dataGridView1.DataSource = listmydata.ToList<MyDatabase>();
      elemsCount++;
   }
}

Answer 2

Similar to Vladimir's answer, I would suggest you need a global variable to keep count of how many times this method has been executed. However, you're probably going to want to make your List variable global as well.

public class YourClass
{
   private int numExecutions = 0;
   private List<MyDatabase> listmydata = new List<MyDatabase>();
   public YourEvent(EventArgs e)
   {  
      MyDatabase mydata = new MyDatabase();
      mydata.id = numExecutions.toString();
      mydata.Name = "YO";
      mydata.ActiveStatus= true;
      listmydata.Add(mydata);
      dataGridView1.DataSource = listmydata.ToList<MyDatabase>();
      numExecutions++;
   }
}