Android Studio - 명시적 인텐트

2022-08-08(36일차)

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🔸 MainActivity
 - Intent 객체 생성
 - putExtra로 name과 value값 지정
 - startActivity

Intent intent = new Intent(MainActivity.this, SecondActivity.class);
intent.putExtra("data", "문자열");
startActivity(intent);​

🔸SecondActivity

 - getIntent로 인텐트를 가져온다.
 - getStringExtra로 name을 가져온다.

Intent intent = getIntent();
String str = intent.getStringExtra("data");​

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📃버튼을 누르면 SecondActivity에 데이터가 출력되도록 하시오.

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📝activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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">

    <Button
        android:id="@+id/btn_explicit"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:onClick="onClickExplicit"
        android:text="액티비티 실행" />

</LinearLayout>

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📝MainActivity.java

package com.example.intent01;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;


import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    public void onClickExplicit(View v) {
        Intent intent = new Intent(MainActivity.this, SecondActivity.class);

        intent.putExtra("data", "moble");
        startActivity(intent);
    }
}

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📝activity_second.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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=".SecondActivity">

    <TextView
        android:id="@+id/textView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="#c3f5e8"
        android:gravity="center"
        android:text="두번째 액티비티"
        android:textAppearance="?android:voiceLanguage"
        android:textSize="40sp" />


</RelativeLayout>

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📝SecondActivity.java

package com.example.intent01;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.widget.TextView;

public class SecondActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_second);

        Intent intent = getIntent();
        String a = intent.getStringExtra("data");

        TextView textView = findViewById(R.id.textView);
        textView.setText(a);
    }
}

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📃EditText에 입력한 데이터가 SecondActivity에 출력되게 하시오.

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📝activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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"
    android:padding="20dp"
    tools:context=".MainActivity">

    <EditText
        android:id="@+id/et"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textSize="30sp" />

    <Button
        android:id="@+id/btn"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@id/et"
        android:layout_marginTop="10dp"
        android:backgroundTint="#9999ff"
        android:text="OK"
        android:textSize="30sp"
        android:onClick="onClickExplicit"/>

</RelativeLayout>

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📝MainActivity.java

package com.example.intent02;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    public void onClickExplicit(View v) {
        EditText et = findViewById(R.id.et);
        String str = et.getText().toString();

        Intent intent = new Intent(MainActivity.this, SecondActivity.class);
        intent.putExtra("data", str + "을/를 입력했습니다.");
        startActivity(intent);
    }
}

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📝activity_second.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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=".SecondActivity">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="#9999ff"
        android:gravity="center"
        android:textColor="@color/black"
        android:textSize="40sp"
        android:id="@+id/tv"/>

</RelativeLayout>

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📝SecondActivity.java

package com.example.intent01;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.widget.TextView;

public class SecondActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_second);

        Intent intent = getIntent();
        String a = intent.getStringExtra("data");

        TextView textView = findViewById(R.id.textView);
        textView.setText(a);
    }
}

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📃리스트뷰에서 해당 아이템을 클릭할 때마다 아이템 안에 있는 데이터 값을 SecondActivity에서 출력되게 하시오.

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📝activity_main.xml

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

    <ListView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/lv"/>

</RelativeLayout>

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📝MainActivity.java

package com.example.intent03;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;

public class MainActivity extends AppCompatActivity {

    String str_items[] = {"한국", "중국", "일본"};

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        ArrayAdapter aa = new ArrayAdapter(this, android.R.layout.simple_list_item_1, str_items);
        ListView lv = findViewById(R.id.lv);
        lv.setAdapter(aa);
        lv.setOnItemClickListener(lis);


    }

    AdapterView.OnItemClickListener lis = new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            Intent intent = new Intent(MainActivity.this, SecondActivity.class);
            intent.putExtra("data", str_items[position]+"");
            startActivity(intent);
        }
    };
}

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📝activity_second.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".SecondActivity">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:gravity="center"
        android:textSize="40sp"
        android:id="@+id/tv"/>

</RelativeLayout>

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📝SecondActivity.java

package com.example.intent03;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.widget.TextView;

public class SecondActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_second);

        Intent intent = getIntent();
        String str = intent.getStringExtra("data");
        ((TextView)findViewById(R.id.tv)).setText(str);
    }
}

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