Mobile Application Development Lecture 5

Lists

In Android development, Lists are a powerful and flexible way to display a collection of items in a user interface. Lists can be viewed using a ListView, which is a view that displays a vertically scrolling list of items. Each item in the list can be customized using an ArrayAdapter, a simple adapter that binds the data to the ListView.

List View + Array Adapter

• ListView:

  • ListView is a UI component that displays a list of items in a vertical scrollable format.
  • It is an efficient way to display large data sets as it only creates and displays the visible items on the screen.

• ArrayAdapter:

  • ArrayAdapter is an adapter used to map an array of data (such as an array or a list of objects) to a ListView.
  • It provides a simple way to connect your data (e.g., strings or objects) with the layout you want to display in each item of the list.

Example Usage:

Here’s a basic example of how to set up a ListView using an ArrayAdapter:

// In your activity
ListView listView = findViewById(R.id.listView);
String[] items = {"Item 1", "Item 2", "Item 3", "Item 4"};
ArrayAdapter<String> adapter = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1, items);
listView.setAdapter(adapter);

• Explanation:
  • ListView is the UI component that will display the list.
  • The ArrayAdapter takes the data (items array), and binds it to a simple layout (android.R.layout.simple_list_item_1) where each item is a single text view.

Key Features of ArrayAdapter:

• Customizing List Item Layouts: If needed, you can create a custom layout for each item in the list by providing your own XML layout resource.
• Efficiency: It optimizes the performance by reusing the list items as you scroll.

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References

Information

• Date: 2025.01.23
• Time: 13:14