The setContent Function in Jetpack Compose: Master the Core of UI Initialization

Jetpack Compose has taken the Android UI development world by storm. It simplifies UI development by making it declarative and functional. But one of the first things you’ll encounter when using Jetpack Compose is the setContent function. In this blog, we'll break down what setContent is, how it works, and why it matters.

What is setContent?

In traditional Android UI development (using XML layouts), you would typically call setContentView() inside your Activity to set the screen's layout. With Jetpack Compose, things have changed!

setContent replaces setContentView when you want to define your UI using Compose.

From now on, if you use Jetpack Compose, use this:

// This is defined for illustration purposes. You can use any composition or composable functions inside setContent{...}.
setContent {
    MyComposableContent()
}

Instead of using the older setContentView method with XML layouts.

Basic Syntax Example

import androidx.activity.ComponentActivity
import androidx.activity.compose.setContent
import androidx.compose.material3.Text
import android.os.Bundle

class MainActivity : ComponentActivity() {…