Ejecutar su primera app en el emulador

You wrote a Composable, now let's run it. In minutes you will watch Hello World appear on a virtual phone right inside Android Studio. 🚀

Every Compose app starts in MainActivity, where setContent connects your Composable tree to the screen. It is the bridge from Android to Compose.

In the toolbar, choose a device to run on: your emulator or a plugged-in phone. Android Studio lists every available target in a dropdown.

Hit the green Run arrow (or Shift+F10). Android Studio builds your app, installs it on the device, and launches it automatically.

Behind the scenes, Gradle compiles your code and bundles it into an installable app. The first build is slow, later ones are much faster.

The emulator boots, your app installs, and your Greeting shows on screen. That text came straight from your Composable function. 🎉

The @Preview pane shows UI fast without installing. Running on a device is the real thing, with full interactivity and actual behavior.

Change your text, press Run again, and the app updates. This tight edit and run loop is how you iterate quickly on real screens.

Logcat at the bottom streams logs from your running app. When something misbehaves, this is the first place you look for clues.

Do not worry if the first launch takes a while. Gradle is downloading and caching libraries. Subsequent runs reuse that cache and fly.

Use the red Stop button to halt the app, then Run again to relaunch. You stay in full control of the build-and-test cycle.

You did it! setContent hooked up your UI, Run built and installed it, and Hello World appeared. Now you can edit, re-run, and watch Logcat as you go.