iOS Dropdown Control

###Overview

I was on a project and needed a dropdown list similar to what I could create in the Actionbar in Android. iOS doesn't have such a control defined. I also didn't want to grab an existing project in Objective-C and then create a wrapper project because many of the solutions didn't have exactly what I wanted. I needed a control that could resize the images and change the color of all the fields displayed.

###Code Example

Method to define data source. DropDownListItem is the object the defines what will be displayed in the dropdown:

    private List<DropDownListItem> GetList1()
    {
        var list = new List<DropDownListItem>();
        list.Add(new DropDownListItem()
            {
                Id = "1",
                DisplayText = "View Animal Selections",
                Image = UIImage.FromBundle("footprint.png")
            });
        list.Add(new DropDownListItem()
            {
                Id = "2",
                DisplayText = "Bugs Are The Bomb",
                Image = UIImage.FromBundle("bug.png"),
                IsSelected = true
            });
        list.Add(new DropDownListItem()
            {
                Id = "3",
                DisplayText = "Connect With Friends",
                Image = UIImage.FromBundle("facebook.png")
            });
        list.Add(new DropDownListItem()
            {
                Id = "4",
                DisplayText = "What Can Hurt You",
                Image = UIImage.FromBundle("toxic.png")
            });
        list.Add(new DropDownListItem()
            {
                Id = "5",
                DisplayText = "Your Connections",
                Image = UIImage.FromBundle("arrow.png")
            });
        list.Add(new DropDownListItem()
            {
                Id = "6",
                DisplayText = "Danger Will Robinson",
                Image = UIImage.FromBundle("fire.png")
            });
        return list;
    }

Method to create and define the properties of the drop down control:

    private DropDownList GetDDL1()
    {
        var ddl = new DropDownList(GetList1().ToArray())
        {
            BackgroundColor = UIColor.FromRGB(220, 220, 220),
            TextColor = UIColor.Blue,
            Opacity = 0.85f,
            TintColor = UIColor.Blue,
            ImageColor = UIColor.Blue
        };
        return ddl;
    }

In the ViewDidLoad method call the custom methods and add the control to the view controller. The control can be animated from any other event you desire.

    public override void ViewDidLoad()
    {
        base.ViewDidLoad();
	
        var ddl = GetDDL1();

        ddl.DropDownListChanged += (e, a) =>
        {
            var index = e; // e is the index selected
            var strValue = a.DisplayText; //a is the dropdown list item object
            var id = a.Id;
            lblMessage.Text = string.Format("Id: {0} => Text: {1}", id, strValue);
            ddl.Toggle();
        };

        this.btnOptions.Clicked += (e, a) =>
        {
            ddl.Toggle();
        };

        btnChange.TouchUpInside += (e, a) =>
        {
            ddl.UpdatedDropDownList(GetList2().ToArray());//Change to a different list
        };

        this.View.Add(ddl);

    }