You can add header and footer view to the suggestion list in the combo box by enabling the ShowDropDownHeaderView and ShowDropDownFooterView properties.

Header content

The header content can be added at the top of the combo box’s Suggestion box. The DropDownHeaderView property is used to set the content of the header. The height of the header in the combo box can be adjusted using the DropDownHeaderViewHeight property.

The following code example illustrate how to set Header content in SfComboBox.

//Create header view
TextView headerView = new TextView(this);
headerView.TextAlignment = TextAlignment.Center;
headerView.TextSize = 20;
headerView.Gravity = GravityFlags.CenterVertical;
headerView.SetTextColor(Color.ParseColor("#006bcd"));
headerView.SetBackgroundColor(Color.ParseColor("#f0f0f0"));
    
comboBox.IsEditableMode = true;
comboBox.ShowDropDownHeaderView = true;
comboBox.DropDownHeaderViewHeight = 50;
comboBox.SelectedDropDownItemColor = Color.Transparent;
//set header view
comboBox.DropDownHeaderView = headerView;

comboBox.TextChanged += (object sender, TextChangedEventArgs e) => 
 {
    headerView.Text = "Search for " + e.Value;
 };

Footer content

The footer content can be added at the bottom of the combo box’s suggestion box. The DropDownFooterView property is used to set the content of the footer. The height of the footer in the combo box can be adjusted using the DropDownFooterViewHeight property.

The following code example illustrate how to set Footer content in SfComboBox.

//create footer view
TextView footerView = new TextView(this);
footerView.Text = "Add New";
footerView.TextAlignment = TextAlignment.Center;
footerView.TextSize = 20;
footerView.SetTextColor(Color.ParseColor("#006bcd"));
footerView.SetBackgroundColor(Color.ParseColor("#f0f0f0"));
footerView.Gravity = GravityFlags.Center;
            
comboBox.IsEditableMode = true;
comboBox.ShowDropDownFooterView = true;
comboBox.DropDownFooterViewHeight = 50;
comboBox.SelectedDropDownItemColor = Color.Transparent;
//set footer view
comboBox.DropDownFooterView = footerView;