ListBoxItem

Introduction

The ListBoxItem class is used by the ListBox control for each instance added to the ListBox.Items property.

Gum Forms includes a default ListBoxItem implementation which includes a single label.

Code Example - Adding ListBoxItems

ListBoxItems can be implicitly instantiated by adding any type of object to a ListBox. The following code creates 20 ListBoxItems, each displaying an integer.

var listBox = new ListBox();
this.Root.Children.Add(listBox.Visual);
listBox.X = 50;
listBox.Y = 50;
listBox.Width = 400;
listBox.Height = 200;

for(int i = 0; i < 20; i++)
{
    listBox.Items.Add(i);
}

ListBoxItems created by adding ints to an Items

ListBoxItems use ToString

By default each item in a ListBox creates a new ListBoxItem. The ListBoxItem calls ToString on the item. Some types, such as int have ToString methods which display expressive values.

Other types simply display their type when added. For example, the following code adds ListBoxItems which displays the type:

for (int i = 0; i < 20; i++)
{
    var cancellationToken = CancellationToken.None;
    listBox.Items.Add(cancellationToken);
}

An object's ToString is displayed by default ListBoxItems

This also includes adding Gum objects (such as Sprite). If a Sprite is added, the Sprite is not displayed, but rather the type of the Sprite is displayed, as shown in the following code:

for (int i = 0; i < 20; i++)
{
    var sprite = new SpriteRuntime();
    // sprite.ToString() returns the Sprite's Name
    sprite.Name = "Test Sprite";
    listBox.Items.Add(sprite);
}

Sprites (and all Gum objects) return their name when ToString is called