DatagridView virtual model with comboboxColumn

Question

is it possible to have different items in different rows within a comboboxcolumn in a datagridview. This would be using virtual mode. Code samples would be great.

Answer 1

I think what you're looking for is here.

The technique involves handling the EditingControlShowing event of the DataGridView control and updating the datasource for the DataGridViewComboBoxEditingControl (presumably based on the values in the other columns in that row).

Edit: here's some code that shows the main points

//Some types we'll need
   enum Jobs
   {
      Programmer,
      Salesman
   }

   enum DrinkCode
   {
      Coffee,
      Coke,
      MountainDew,
      GinAndTonic
   }

   internal class Drink
   {
      public DrinkCode Code { get; set; }
      public string Name { get; set; }
      public bool Caffeinated { get; set; }
      public bool Alcoholic { get; set; }
   }

   internal class Person
   {
      public string Name { get; set; }

      public Jobs Job { get; set; }

      public DrinkCode Drink { get; set; }
   }

// the form class
public partial class Form1 : Form
{

  public Form1()
  {
     InitializeComponent();
  }

  private void Form1_Load(object sender, EventArgs e)
  {
     BindingSource bindingSource = new BindingSource();
     bindingSource.DataSource = FindPersons();
     this.dataGridView1.DataSource = bindingSource;

     DataGridViewComboBoxColumn column =
         new DataGridViewComboBoxColumn();
     {
        column.DataPropertyName = "Drink";
        column.HeaderText = "beverage";
        column.DisplayMember = "Name";
        column.ValueMember = "Code";
        column.DataSource = BuildDrinksList();
     }
     dataGridView1.Columns.Add(column);
     //handling this event is the nub of the solution
     dataGridView1.EditingControlShowing += 
        new DataGridViewEditingControlShowingEventHandler(dataGridView1_EditingControlShowing);
  }


  void dataGridView1_EditingControlShowing(object sender, DataGridViewEditingControlShowingEventArgs e)
  {
     //When the focus goes into the combo box cell, we can update the contents of the dropdown
     // 
     DataGridViewComboBoxEditingControl comboBox = e.Control as DataGridViewComboBoxEditingControl;
     //if you have more than one drop down this is not going to be good enough, but hey, it's an example!
     if (comboBox != null)
     {
        BindingSource bindingSource = this.dataGridView1.DataSource as BindingSource;
        Person person = bindingSource.Current as Person;
        BindingList<Drink> bindingList = this.BuildDrinksList(person);
        comboBox.DataSource = bindingList;

     }

  }

  //the rest of this is just data to make the example work

  private BindingList<Drink> BuildDrinksList()
  {
     var drinks = new BindingList<Drink>();

     drinks.Add(new Drink() { Alcoholic = false, Caffeinated = true, Code = DrinkCode.Coffee, Name = "Coffee" });
     drinks.Add(new Drink() { Alcoholic = false, Caffeinated = true, Code = DrinkCode.Coke, Name = "Coke" });
     drinks.Add(new Drink() { Alcoholic = false, Caffeinated = true, Code = DrinkCode.MountainDew, Name = "Mountain Dew" });
     drinks.Add(new Drink() { Alcoholic = true, Caffeinated = false, Code = DrinkCode.GinAndTonic, Name = "Gin and Tonic" });

     return drinks;
  }

  private BindingList<Drink> BuildDrinksList(Person p)
  {
     var drinks = new BindingList<Drink>();

     if (p.Job == Jobs.Programmer)
     {
        drinks.Add(new Drink() { Alcoholic = false, Caffeinated = true, Code = DrinkCode.Coffee, Name = "Coffee" });
        drinks.Add(new Drink() { Alcoholic = false, Caffeinated = true, Code = DrinkCode.Coke, Name = "Coke" });
        drinks.Add(new Drink() { Alcoholic = false, Caffeinated = true, Code = DrinkCode.MountainDew, Name = "Mountain Dew" });
     }
     if (p.Job == Jobs.Salesman)
     {
        drinks.Add(new Drink() { Alcoholic = true, Caffeinated = false, Code = DrinkCode.GinAndTonic, Name = "Gin and Tonic" });
     }
     return drinks;
  }

  private BindingList<Person> FindPersons()
  {
     BindingList<Person> bindingList = new BindingList<Person>();
     bindingList.Add(new Person() { Job = Jobs.Programmer, Drink = DrinkCode.Coffee, Name = "steve" });
     bindingList.Add(new Person() { Job = Jobs.Salesman, Drink = DrinkCode.GinAndTonic, Name = "john" });
     return bindingList;
  }

}