how to set SelectedIndex in DataGridViewComboBoxColumn?

Question

i am using a datagridview in that i am using a datagridviewcomboboxcolumn, comboboxcolumn is displaying text but the problem is i want to select the first item of comboboxco

Answer 1

If DataGridViewComboBoxCell already exist:

DataTable dt = new DataTable();
dt.Columns.Add("Item");
dt.Columns.Add("Value");
dt.Rows.Add("Item 1", "0");
dt.Rows.Add("Item 2", "1");
dt.Rows.Add("Item 3", "2");
dt.Rows.Add("Item 4", "3");

for (int i = 0; i < dvg.Rows.Count; i++)
{
    DataGridViewComboBoxCell comboCell = (DataGridViewComboBoxCell)dvg.Rows[i].Cells[1];
    comboCell.DisplayMember = "Item";
    comboCell.ValueMember = "Value";
    comboCell.DataSource = dt;
};

Answer 2

If I had known about doing it in this event, it would have saved me days of digging and
trial and errors trying to get it to set to the correct index inside the CellEnter event.

Setting the index of the DataGridViewComboBox is the solution I have been looking for.....THANKS!!!

In reviewing all the issues other coders have been experiencing with trying to set
the index inside of a DataGridViewComboBoxCell and also after looking over your code,
all that anyone really needs is:
1. Establish the event method to be used for the "EditingControlShowing" event.
2. Define the method whereby it will:
    a. Cast the event control to a ComboBox.
    b. set the "SelectedIndex" to the value you want.
        In this example I simply set it to "0", but you'd probably want to apply so real life logic here.

Here's the code I used:

private void InitEvents()
{

    dgv4.EditingControlShowing += new DataGridViewEditingControlShowingEventHandler( dgv4EditingControlShowing );

}


private void dgv4EditingControlShowing( object sender, DataGridViewEditingControlShowingEventArgs e )
{
   ComboBox ocmb = e.Control as ComboBox;
   if ( ocmb != null )
   {
      ocmb.SelectedIndex = 0;
   }
}

Answer 3

I've had some real trouble with ComboBoxes in DataGridViews and did not find an elegant way to select the first value. However, here is what I ended up with:

public static void InitDGVComboBoxColumn<T>(DataGridViewComboBoxCell cbx, List<T> dataSource, String displayMember, String valueMember)
{
    cbx.DisplayMember = displayMember;
    cbx.ValueMember = valueMember;
    cbx.DataSource = dataSource;
    if (cbx.Value == null)
    {
        if(dataSource.Count > 0)
        {
            T m = (T)cbx.Items[0];
            FieldInfo fi = m.GetType().GetField(valueMember, BindingFlags.Instance | BindingFlags.Static | BindingFlags.NonPublic | BindingFlags.Public);
            cbx.Value = fi.GetValue(m);
        }
    }
}

It basically sets the .Display and .ValueMember properties of the DataGridViewComboBoxCell and uses a List as DataSource. It then takes the first item, and uses reflection to get the value of the member that was used as ValueMember and sets the selected value via .Value

Use it like this:

public class Customer
{
    private String name;
    public String Name
    {
        get {return this.name; }
        set {this.name = value; }
    }

    private int id;
    public int Id
    {
        get {return this.id; }
        set {this.id = value; }
    }
}

public class CustomerCbx
{
    private String display;
    public String Display
    {
        get {return this.display; }
        set {this.display = value; }
    }

    private Customer value;
    public Customer Value
    {
        get {return this.value; }
        set {this.value = value; }
    }
}

public class Form{
private void Form_OnLoad(object sender, EventArgs e)
{
        //init first row in the dgv
        if (this.dgv.RowCount > 0)
        {
            DataGridViewRow row = this.dgv.Rows[0];
            DataGridViewComboBoxCell cbx = (DataGridViewComboBoxCell)row.Cells[0];

            Customer c1 = new Customer(){ Name = "Max Muster", ID=1 };
            Customer c2 = new Customer(){ Name = "Peter Parker", ID=2 };
            List<CustomerCbx> custList = new List<CustomerCbx>()
            {
                new CustomerCbx{ Display = c1.Name, Value = c1},
                new CustomerCbx{ Display = c2.Name, Value = c2},
            }

            InitDGVComboBoxColumn<CustomerCbx>(cbx, custList, "display", "value");
        }
    }
}
}

It seems pretty hacky to me, but I couldn't find any better way so far (that also works with complex objects other than just Strings). Hope that will save the search for some others ;)

Answer 4

the best way to set the value of a datagridViewComboBoxCell is:

DataTable dt = new DataTable();
dt.Columns.Add("Item");
dt.Columns.Add("Value");
dt.Rows.Add("Item1", "0");
dt.Rows.Add("Item1", "1");
dt.Rows.Add("Item1", "2");
dt.Rows.Add("Item1", "3");
DataGridViewComboBoxColumn cmb = new DataGridViewComboBoxColumn();
cmb.DefaultCellStyle.Font = new Font("Tahoma", 8, FontStyle.Bold);
cmb.DefaultCellStyle.ForeColor = Color.BlueViolet;
cmb.FlatStyle = FlatStyle.Flat;
cmb.Name = "ComboColumnSample";
cmb.HeaderText = "ComboColumnSample";
cmb.DisplayMember = "Item";
cmb.ValueMember = "Value";
DatagridView dvg=new DataGridView();
dvg.Columns.Add(cmb);
cmb.DataSource = dt;
for (int i = 0; i < dvg.Rows.Count; i++)
{
dvg.Rows[i].Cells["ComboColumnSample"].Value = (cmb.Items[0] as 
DataRowView).Row[1].ToString();
}

It worked with me very well

Answer 5

The values available in the combobox can be accessed via items property

row.Cells[col.Name].Value = (row.Cells[col.Name] as DataGridViewComboBoxCell).Items[0];

Answer 6

You need to set the Items for the new cell. This must be auto done by the column when creating a new row from the UI.

 var cell = new DataGridViewComboBoxCell() { Value = "SomeText" };
 cell.Items.AddRange(new String[]{"SomeText", "Abcd", "123"});