안드로이드 스튜디오 - Intent (1)

Intent란?

- 의도, 요구, 의사 전달, 요청

 

- 요청 관계

    -> 액티비티와 액티비티

    -> 안드로이드 시스템과 myApp

    -> 다른 앱과 내 앱 ( 상호합의 필요)

- 요청의 전달

    -> 전달만 하는 요청

    -> 리턴을 받는 요청

 

- 버튼을 클릭하면 editText값에 따라 전달받은 액티비티의 textView에 값 변경

MainActivity

package com.example.intent

import android.content.Intent
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.widget.Button
import android.widget.EditText

class MainActivity : AppCompatActivity() {

    private val intent_button : Button by lazy{ findViewById(R.id.intent_button) }
    private val input_number : EditText by lazy { findViewById(R.id.input_number) }
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        intent_button.setOnClickListener{
            var intent = Intent(this,IntentActivity::class.java)
            intent.putExtra("data",
                    input_number.text.toString()
            )
            startActivity(intent)
        }
    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <EditText
        android:id="@+id/input_number"
        android:hint="숫자입력"
        android:layout_width="100dp"
        android:layout_height="wrap_content"
        android:layout_margin="10dp"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintBottom_toTopOf="@id/intent_button"/>

    <Button
        android:id="@+id/intent_button"
        android:text="인텐트 넘기기"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"/>


</androidx.constraintlayout.widget.ConstraintLayout>

 

IntentActivity

package com.example.intent

import android.content.Intent
import android.os.Bundle
import android.widget.TextView
import androidx.appcompat.app.AppCompatActivity

class IntentActivity : AppCompatActivity() {

    private val view_intent : TextView by lazy { findViewById(R.id.view_intent) }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_intent)
        var num = intent.getStringExtra("data")
        when(num){
            "1" -> view_intent.setText("1이 들어옴")
            "2" -> view_intent.setText("2가 들어옴")
            else -> view_intent.setText("아무것도 안들어옴")
        }

    }
}

activity_intent.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:app="http://schemas.android.com/apk/res-auto">

    <TextView
        android:id="@+id/view_intent"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"/>
</androidx.constraintlayout.widget.ConstraintLayout>