Harvey's TechNote

class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        val goToSecond = findViewById<Button>(R.id.gotoSecond)
        goToSecond.setOnClickListener{
            val intent = Intent(this,SecondActivity::class.java)
            startActivity(intent)
        }


    }

}

class SecondActivity : AppCompatActivity() {


    lateinit var viewModel: SecondViewModel
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_second)

        viewModel = ViewModelProvider(this).get(SecondViewModel::class.java)
        viewModel.a()
        viewModel.b()

    }
}

class SecondViewModel : ViewModel(){

    fun a(){
        CoroutineScope(Dispatchers.IO).launch{

            for(i in 0..10){
                delay(1000)
                Log.d("SecondViewModel A",i.toString())
            }

        }
    }


    fun b(){

        viewModelScope.launch {
            for(i in 0..10){
                delay(1000)
                Log.d("SecondViewModel B",i.toString())
            }
        }



    }
}

class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        val api = RetrofitInstance.getInstance().create(MyApi::class.java)

        // 1. 유저 정보를 가져와서 (userId)
        api.getPost1().enqueue(object : Callback<Post> {
            override fun onResponse(call: Call<Post>, response: Response<Post>) {
                Log.d("API1", response.body().toString())
                // 2. userId 기반으로 데이터를 가져오고 가져온 닉네임값
                api.getPostNumber(2).enqueue(object : Callback<Post> {
                    override fun onResponse(call: Call<Post>, response: Response<Post>) {
                        Log.d("API2", response.body().toString())
                        // 3. 닉네임 기반으로 데이터를 가져오고 유저의 댓글을 가져와서
                        api.getPostNumber(3).enqueue(object : Callback<Post> {
                            override fun onResponse(call: Call<Post>, response: Response<Post>) {
                                Log.d("API3", response.body().toString())
                                // 4. 유저의 댓글 기반으로, 대댓글
                                api.getPostNumber(4).enqueue(object : Callback<Post> {
                                    override fun onResponse(call: Call<Post>, response: Response<Post>) {
                                        Log.d("API4", response.body().toString())
                                    }

                                    override fun onFailure(call: Call<Post>, t: Throwable) {
                                        Log.d("API4", "fail")
                                    }

                                })
                            }

                            override fun onFailure(call: Call<Post>, t: Throwable) {
                                Log.d("API3", "fail")
                            }

                        })
                    }

                    override fun onFailure(call: Call<Post>, t: Throwable) {
                        Log.d("API2", "fail")
                    }

                })
            }

            override fun onFailure(call: Call<Post>, t: Throwable) {
                Log.d("API1", "fail")
            }

        })







    }
}

implementation("org.jetbrains.kotlinx:kotlinx-coroutines-android:1.6.0")
implementation("androidx.lifecycle:lifecycle-viewmodel-ktx:2.4.1")

class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        Log.d("TEST","START")
        CoroutineScope(Dispatchers.IO).launch{
            Log.d("TEST","CoroutineScope START")
            a()
            b()
            Log.d("TEST","CoroutineScope END")
        }

        Log.d("TEST","END")
    }

    //START ->END ->AP1 ->BP1 -> AP2 ->BP2


    suspend fun a(){   //suspend:유예하다.

        //a작업 2초정도 걸림.

        delay(1000)
        Log.d("TEST","AP1")
        delay(1000)
        Log.d("TEST","API2" )
    }
    suspend fun b(){

        //B작업 2초정도 걸림.

        delay(1000)

        Log.d("TEST","BP1")

        delay(1000)
        Log.d("TEST","BPI2" )
    }
}