Activity간 데이터전달(putExtra, getExtras,getIntent)

Activity간 데이터전달

(putExtra, getExtras, getIntent)

- 이번글에서는 Intent를 통해서 Activity를 전환후에 그 전 Activity에서 사용하던 값들을 어떻게 가져오는지 살펴본다.

- 엄청 많이 사용되는데 엄청 쉬우니까 슬쩍 봐두면 좋다.

어려운 부분은 없으니

바로 살펴보면

[String]

먼저 Main에서 

Second Activity로

전환하면서

putExtra로

String값을 보낸다

public class MainActivity extends ActionBarActivity
{
    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        String str = "hi";

        Intent intent = new Intent(MainActivity.this, SecondActivity.class);
        intent.putExtra("itpangpang",str);
        startActivity(intent);
    }
}

SecondActivity에서

값을 받는다.

public class SecondActivity extends ActionBarActivity
{
    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_second);
        Intent intent = getIntent();
        Log.d("ITPANGPANG",intent.getExtras().getString("itpangpang"));
    }
}

새로운 코드가

3줄 쓰였다

MainActivity

intent.putExtra("itpangpang",str);

Key, Value를 통해서 값을 넣는다

itpangpang이라는 보관함에

str(hi)를 보관하는 것이다.

SecondActivity

getIntent();

말 그대로 

자신을 호출한

Activity한테서

인텐트값을

받는다는 말입니다.

intent.getExtras().getString("itpangpang");

itpangpang 보관함에 들어있는

String을 가져오겠다는 뜻입니다.

[int]

public class MainActivity extends ActionBarActivity
{
    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
       
        int i = 1;
        Intent intent = new Intent(MainActivity.this, SecondActivity.class);
        intent.putExtra("itpangpang", i);
        startActivity(intent);
    }
}

public class SecondActivity extends ActionBarActivity
{
    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_second);
        Intent intent = getIntent();
        Log.d("ITPANGPANG",""+intent.getExtras().getInt("itpangpang"));
    }
}

[String 배열]

public class MainActivity extends ActionBarActivity
{
    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        String strArray[] = {"hi","hello"};

        Intent intent = new Intent(MainActivity.this, SecondActivity.class);
        intent.putExtra("itpangpang", strArray);
        startActivity(intent);
    }
}

public class SecondActivity extends ActionBarActivity
{
    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_second);
        Intent intent = getIntent();
        int i = -1;
        String str[] = intent.getExtras().getStringArray("itpangpang");
        while(true)
        {
            i++;
            try
            {
                Log.d("ITPANGPANG",""+str[i]);
            }
            catch (Exception e){break;}
        }
    }
}

[Boolean]

public class MainActivity extends ActionBarActivity
{
    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        boolean isboolean = false;

        Intent intent = new Intent(MainActivity.this, SecondActivity.class);
        intent.putExtra("itpangpang", isboolean);
        startActivity(intent);
    }
}

public class SecondActivity extends ActionBarActivity
{
    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_second);
        Intent intent = getIntent();
        Log.d("ITPANGPANG",""+intent.getExtras().getBoolean("itpangpang"));
    }
}

[Serializable를 이용해서 한번에 보내기]

[MainActivity.java]

public class MainActivity extends ActionBarActivity 
{
    @Override
    protected void onCreate(Bundle savedInstanceState) 
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        boolean isboolean = false;
        String str = "hi";
        String strArray[] = {"hi", "hello"};
        int i = 1;
        int intArray[] = {1, 2, 3, 4};

        Intent intent = new Intent(MainActivity.this, SecondActivity.class);
        Data data = new Data(isboolean, str, strArray,i, intArray);
        intent.putExtra("itpangpang", data);
        startActivity(intent);
    }
}

[Data.java]

public class Data implements Serializable
{
    boolean isboolean;
    String str;
    String strArray[];
    int i;
    int intArray[];

    public Data(boolean isboolean, String str, String[] strArray, int i, int[] intArray)
    {
        this.isboolean = isboolean;
        this.str = str;
        this.strArray = strArray;
        this.i = i;
        this.intArray = intArray;
    }
}

[SecondActivity.java]

public class SecondActivity extends ActionBarActivity
{
    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_second);
        Intent intent = getIntent();
        Data data = (Data)intent.getSerializableExtra("itpangpang");
        Log.d("ITPANGPANG",""+data.isboolean);
        Log.d("ITPANGPANG",""+data.str);
        Log.d("ITPANGPANG",""+data.strArray.length);
        Log.d("ITPANGPANG",""+data.i);
        Log.d("ITPANGPANG",""+data.intArray.length);
    }
}

이런식으로 한번에 가져올 수 있다.

배열들은 귀찮아서 Length로 받았다.