C# – Focus next control when pressing ‘TAB’ key

private void dataGridView1_KeyDown(object sender, KeyEventArgs e)
{
    e.SuppressKeyPress = true;
    int iColumn = dataGridView1.CurrentCell.ColumnIndex;
    int iRow = dataGridView1.CurrentCell.RowIndex;
    if (iColumn == dataGridView1.Columncount-1)
    {
        if (dataGridView1.RowCount > (iRow + 1))
        {
            dataGridView1.CurrentCell = dataGridView1[1, iRow + 1];
        }
        else
        {
            //focus next control
        }
    }
    else
        dataGridView1.CurrentCell = dataGridView1[iColumn + 1, iRow];
}

There is a list of predefined string constants for non-alphanumeric keys. For example, {TAB} is for a Tab key. Here is MSDN article with all constants: https://msdn.microsoft.com/en-us/library/system.windows.forms.sendkeys.send%28v=vs.110%29.aspx?f=255&MSPPError=-2147217396

You may also consider using SendKeys.SendWait instead. This method will ensure that target application processes sent key before your application continues. For example:

SendKeys.SendWait("{TAB}");