Android Studio - 액티비티 간의 상호작용

2022-08-09(37일차)

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📃버튼을 클릭하면 다른 액티비티로 이동하시오.

📝layout1.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:padding="20dp">

    <TextView
        android:id="@+id/tv_info"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="버튼을 누르면 입력 액티비티를 실행합니다."
        android:textSize="20sp" />

    <Button
        android:id="@+id/btn"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="입력창 실행"
        android:textSize="25sp" />

    <TextView
        android:id="@+id/tv"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:gravity="center"
        android:textSize="30sp" />

</LinearLayout>

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📝layout2.xml

 

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

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

    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:layout_marginLeft="200dp">

        <Button
            android:id="@+id/btn_change"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="CHANGE" />

        <Button
            android:id="@+id/btn_cancel"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="CANCEL" />


    </LinearLayout>


</LinearLayout>

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📝MainActivity.java

package com.example.test02;

import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;

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

public class MainActivity extends AppCompatActivity {
    final int REQUEST_CODE_START_INPUT = 1;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.layout1);


        findViewById(R.id.btn).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(MainActivity.this, MainActivity2.class);
                startActivity(intent);
            }
        });
    }
}

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📝MainActivity2.java

package com.example.test02;

import androidx.appcompat.app.AppCompatActivity;

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

public class MainActivity2 extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.layout2);

        findViewById(R.id.btn_change).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                EditText et = (EditText) findViewById(R.id.et);

                Intent intent = new Intent();
                intent.putExtra("input", et.getText().toString()+"");
                setResult(RESULT_OK, intent);

                finish();
            }
        });

        findViewById(R.id.btn_cancel).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                finish();
            }
        });
    }
}

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📃EditText의 text값이 Log에 출력되도록 하시오.

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📝MainActivity.java

package com.example.test02;

import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;

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

public class MainActivity extends AppCompatActivity {
    final int REQUEST_CODE_START_INPUT = 1;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.layout1);


        findViewById(R.id.btn).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(MainActivity.this, MainActivity2.class);
                startActivityForResult(intent, REQUEST_CODE_START_INPUT);
            }
        });
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        Log.i("jyeon", "onActivityResult");

        if(resultCode == RESULT_OK) {
            String str = data.getStringExtra("input");
            Log.i("jyeon", "onActivityResult : " + str);
        }
    }
}

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📝MainActivity2.java

package com.example.test02;

import androidx.appcompat.app.AppCompatActivity;

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

public class MainActivity2 extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.layout2);

        findViewById(R.id.btn_change).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                EditText et = (EditText) findViewById(R.id.et);

                Intent intent = new Intent();
                intent.putExtra("input", et.getText().toString()+"");
                setResult(RESULT_OK, intent);

                finish();
            }
        });

        findViewById(R.id.btn_cancel).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                finish();
            }
        });
    }
}

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📃추가적으로, EditText에 입력한 값이 첫 번째 액티비티 화면의 TextView에도 출력되게 하시오.

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📝MainActivity.java

package com.example.test02;

import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;

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

public class MainActivity extends AppCompatActivity {
    final int REQUEST_CODE_START_INPUT = 1;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.layout1);


        findViewById(R.id.btn).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(MainActivity.this, MainActivity2.class);
                startActivityForResult(intent, REQUEST_CODE_START_INPUT);
            }
        });
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        Log.i("jyeon", "onActivityResult");
        TextView tv = findViewById(R.id.tv);

        if(resultCode == RESULT_OK) {
            String str = data.getStringExtra("input");
            tv.setText(str+"을/를 입력하셨습니다.");
        }
    }
}

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📝MainActivity.java

package com.example.test02;

import androidx.appcompat.app.AppCompatActivity;

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

public class MainActivity2 extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.layout2);

        findViewById(R.id.btn_change).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                EditText et = (EditText) findViewById(R.id.et);

                Intent intent = new Intent();
                intent.putExtra("input", et.getText().toString()+"");
                setResult(RESULT_OK, intent);

                finish();
            }
        });

        findViewById(R.id.btn_cancel).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                finish();
            }
        });
    }
}

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◾ onActivityResult 메소드의 파라미터가 의미하는 것들

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📃리스트뷰의 아이템을 누르면 다음 액티비티로 이동하고, 텍스트뷰에 있는 텍스트를 Log에 출력하시오.

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📝layout1.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:padding="10dp">

    <Button
        android:id="@+id/btn_add"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="add"
        android:textSize="25sp" />

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

</LinearLayout>

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📝layout2.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="20dp">

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

    <Button
        android:id="@+id/btn_ok"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/et_input"
        android:layout_alignParentRight="true"
        android:text="OK"
        android:textSize="20sp" />

    <Button
        android:id="@+id/btn_cancel"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/et_input"
        android:layout_marginRight="20dp"
        android:layout_toLeftOf="@id/btn_ok"
        android:text="cancel"
        android:textSize="20sp" />

</RelativeLayout>

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📝MainActivity.java

package com.example.test04;

import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;

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

public class MainActivity2 extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.layout2);

        EditText et_input = findViewById(R.id.et_input);
        et_input.setText(getIntent().getStringExtra("data"));

        findViewById(R.id.btn_ok).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                Intent intent = getIntent();
                EditText et_input = findViewById(R.id.et_input);

                String str = et_input.getText().toString();
                intent = intent.putExtra("input", str+"");
                setResult(RESULT_OK, intent);

                finish();
            }
        });

        findViewById(R.id.btn_cancel).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                finish();
            }
        });
    }
}

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📝MainActivity2.java

package com.example.test02;

import androidx.appcompat.app.AppCompatActivity;

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

public class MainActivity2 extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.layout2);

        findViewById(R.id.btn_change).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                EditText et = (EditText) findViewById(R.id.et);

                Intent intent = new Intent();
                intent.putExtra("input", et.getText().toString()+"");
                setResult(RESULT_OK, intent);

                finish();
            }
        });

        findViewById(R.id.btn_cancel).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                finish();
            }
        });
    }
}

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📝MainActivity.java

package com.example.test04;

import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;

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

import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {
    ArrayList<String> al = new ArrayList<>();
    ArrayAdapter<String> aa;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.layout1);

        al.add("한국");
        al.add("중국");
        al.add("일본");

        aa = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1, al);
        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, MainActivity2.class);
            intent.putExtra("data", al.get(position)+"");
            intent.putExtra("index", position); // 클릭한 아이템의 해당 인덱스를 저장한다.
            startActivityForResult(intent, 1);
        }
    };

    @Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        if(resultCode == RESULT_OK) {
            if(requestCode == 1) {
                String str = data.getStringExtra("result");
                Log.i("jyeon", str + "");
                int index = data.getIntExtra("index", -1);
                al.set(index, str);
                aa.notifyDataSetChanged();
            }
        }

    }
}

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📝MainActivity2.java

package com.example.test04;

import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;

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

public class MainActivity2 extends AppCompatActivity {
    Intent myOrgIntent;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.layout2);

        EditText et_input = findViewById(R.id.et_input);
        et_input.setText(getIntent().getStringExtra("data"));

        findViewById(R.id.btn_ok).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                myOrgIntent = getIntent();
                EditText et_input = findViewById(R.id.et_input);

                String str = et_input.getText().toString();
                myOrgIntent.putExtra("result", str+"");
                setResult(RESULT_OK, myOrgIntent);

                finish();
            }
        });

        findViewById(R.id.btn_cancel).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                finish();
            }
        });
    }
}

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📃ADD 버튼 누르면 리스트뷰 아이템을 추가하시오.

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📝MainActivity.java

package com.example.test04;

import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;

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

import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {
    ArrayList<String> al = new ArrayList<>();
    ArrayAdapter<String> aa;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.layout1);

        al.add("한국");
        al.add("중국");
        al.add("일본");

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

        findViewById(R.id.btn_add).setOnClickListener(lis_btn);
    }

    View.OnClickListener lis_btn = new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent i = new Intent(MainActivity.this, MainActivity2.class);
            startActivityForResult(i, 2);
        }
    };

    AdapterView.OnItemClickListener lis = new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            Intent intent = new Intent(MainActivity.this, MainActivity2.class);
            intent.putExtra("data", al.get(position)+"");
            intent.putExtra("index", position); // 클릭한 아이템의 해당 인덱스를 저장한다.
            startActivityForResult(intent, 1);
        }
    };

    @Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        if(resultCode == RESULT_OK) {
            if(requestCode == 1) {
                String str = data.getStringExtra("result");
                Log.i("jyeon", str + "");
                int index = data.getIntExtra("index", -1);
                al.set(index, str);
                aa.notifyDataSetChanged();
            }

            else if(requestCode == 2) {
                String str = data.getStringExtra("result");
                al.add(str);
                aa.notifyDataSetChanged();
            }
        }

    }


}

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📝MainActivity2.java

package com.example.test04;

import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;

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

public class MainActivity2 extends AppCompatActivity {
    Intent myOrgIntent;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.layout2);

        EditText et_input = findViewById(R.id.et_input);
        et_input.setText(getIntent().getStringExtra("data"));

        findViewById(R.id.btn_ok).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                myOrgIntent = getIntent();
                EditText et_input = findViewById(R.id.et_input);

                String str = et_input.getText().toString();
                myOrgIntent.putExtra("result", str+"");
                setResult(RESULT_OK, myOrgIntent);

                finish();
            }
        });

        findViewById(R.id.btn_cancel).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                finish();
            }
        });
    }
}

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