20230611.md

Today I Learn

• Date: 2023/06/11

My First Compose Project

Boilerplate project Code

package com.example.myfirstcomposeproject

import android.os.Bundle
import androidx.activity.ComponentActivity
import androidx.activity.compose.setContent
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.material.MaterialTheme
import androidx.compose.material.Surface
import androidx.compose.material.Text
import androidx.compose.runtime.Composable
import androidx.compose.ui.Modifier
import androidx.compose.ui.tooling.preview.Preview
import com.example.myfirstcomposeproject.ui.theme.MyFirstComposeProjectTheme

class MainActivity : ComponentActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContent {
            MyFirstComposeProjectTheme {
                // A surface container using the 'background' color from the theme
                Surface(
                    modifier = Modifier.fillMaxSize(),
                    color = MaterialTheme.colors.background
                ) {
                    Greeting("Android")
                }
            }
        }
    }
}

@Composable
fun Greeting(name: String) {
    Text(text = "Hello $name!")
}

@Preview(showBackground = true)
@Composable
fun DefaultPreview() {
    MyFirstComposeProjectTheme {
        Greeting("Android")
    }
}

onCreate

[출처]link

    /**
     * {@inheritDoc}
     *
     * If your ComponentActivity is annotated with {@link ContentView}, this will
     * call {@link #setContentView(int)} for you.
     */
    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        // Restore the Saved State first so that it is available to
        // OnContextAvailableListener instances
        mSavedStateRegistryController.performRestore(savedInstanceState);
        mContextAwareHelper.dispatchOnContextAvailable(this);
        super.onCreate(savedInstanceState);
        ReportFragment.injectIfNeededIn(this);
        if (mContentLayoutId != 0) {
            setContentView(mContentLayoutId);
        }
    }

Called when the activity is first created. This is where you should do all of your normal static set up: create views, bind data to lists, etc. This method also provides you with a Bundle containing the activity's previously frozen state, if there was one. Always followed by onStart().

• Activity가 처음 생성될 때 호출됨.
• 여기에서 모든 일반 정적 설정(View 만들기, 목록에 데이터 바인딩 등)을 수행해야 함.
• 이 방법은 또한 Activity의 이전 고정 상태(있는 경우)를 포함하는 번들을 제공함.
• 항상 onStart()가 따라옵니다.