androidx.activity.ComponentActivity#ComponentActivity()

As we all know, non-compose needs to inherit AppCompatActivity to create an Activity

They eventually inherit as follows:

ComponentActivity: ComponentActivity, ComponentActivity, ComponentActivity, ComponentActivity, ComponentActivity, ComponentActivity

Base classes that combine higher-level component activities, not all functionality is built directly into this class, reducing coupling

Compose inherits ComponentActivity: Compose inherits ComponentActivity: Compose inherits ComponentActivity Where to create and load Componse UI, how does not seem to find 😅, please everyone center eyeglasses frame, look up, just 👆ComponentActivity official explanation 👆 I this violent temper, you this is not fart to the air? How do you create the Compose UI?

At this point you need to use the ComposeView passed into the setContentView(View), 😆😆 do you feel reasonable?

setContentView(
  ComposeView(this).apply { setContent { ........ }})Copy the code

Let’s see what’s going on in the ComposeView?

The nested 😅 pseudocode is as follows:

ComposeView(this){
   setContent{
     AbstractComposeView#createComposition(){
       ViewGroup.setContent(){
         // Create AndroidComposeView and pass in doSetContent(...)
         //AndroidComposeView inherits from ViewGroup
         ViewGroup.doSetContent(){
            WrappedComposition#setContent(){
              owner.setOnViewTreeOwnersAvailable {
                   CompositionLocalProvider(...) {
                     ProvideAndroidCompositionLocals(owner, content)
                   }
                }
              }
          }
        }
      }
    }
}
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The actual conversion of functions into concrete interfaces is done in AndroidComposeView





OnMeasure, onLayout, dispatchDraw






onMeasure






onLayout






dispatchDraw


The 😎 creation process is pretty much the same as the one above, ending up in ViewGroup mode, except that we don’t feel as much 🙈🙈 in the Compose UI framework

For example, if you want to create an onCreate ComponseView for your Activity, you can use the following lib libraries to create an extension function for the Activity

implementation 'androidx. Activity: activity - compose: the latest version number'
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After relying on the lib library above, you can use the extension library below

fun ComponentActivity.setContent(
    parent: CompositionContext? = null.content: @Composable () -> Unit
)
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The final version is as follows:

override fun onCreate(savedInstanceState: Bundle?). {
        super.onCreate(savedInstanceState)
        setContent {
           // Pass in the Compose UI decorated with @composable to display the content}}Copy the code

The article is very short, there is no dry goods to talk about. The so-called master leads the door and cultivates himself. Please eat slowly and leave without giving a thumbs up.