Android app development: fixing bugs before creating them

Understand how a java.lang.NullPointerException occurs when invoking a method on a null object due to mismatched activity xml. Fix by using the correct activity_main xml and adding missing resources.

Demonstrates how to diagnose and fix android activity not found errors when sending text via implicit intents, using chooser, package manager, and toast messages to ensure a valid target app.

This lecture explains the android.os.NetworkOnMainThreadException and shows how network requests must run in a background thread to avoid crashing, including adding internet permission and moving requests to a background task.

Fix an illegal state exception by applying a Theme.AppCompat theme to the affected activity in the Android manifest, and verify manifest changes when debugging since logs may omit manifest details.

Explore Kotlin uninitialized property access exception and fixes, including immediate primitive initialization, lazy for heavy objects, marking variables as knowable, and checking initialization before use.

Avoid creating thousands of threads; use thread pools and IO schedulers to manage async tasks and prevent implicit overflow and stack overflow errors.

Explore how the Android application class onCreate runs before other activities, enabling library initialization. Fix error 12 by declaring a custom application in the manifest.

Diagnose an illegal state exception caused by vertical scrolling with infinite constraints in XML and compose, and outline solutions: remove scroll view, use a column, or cap the maximum constraint.

Explore common Android development bugs and practical solutions, and learn an approach to solve other issues across projects. Share feedback and stay tuned for next courses.