Android：Intent传递数据

接收调用的Activity销毁后返回的数据

调用MainActivity中：显式Intent调用并设置requestCode为1，在回调函数中接收返回的数据。

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.activity_main);
        Button button = (Button)findViewById(R.id.button_exit);
        button.setOnClickListener(new View.OnClickListener() {
			@Override
			public void onClick(View v) {
				Intent intent = new Intent(MainActivity.this, TestActivity.class);
				startActivityForResult(intent, 1);
			}
		});
    }
    
    //调用的Activity销毁返回后执行的回调方法
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    	switch (requestCode) {
		case 1:
			if(resultCode == RESULT_OK){
				String value = data.getStringExtra("key");
				Log.d("debug", value);
			}
			break;
		default:
			break;
		}
    }
}

被调用Activity中：通过两种不同形式返回不同数据（按button返回和按系统返回键返回）

public class TestActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_test);      
        Button button = (Button)findViewById(R.id.test_button);
        button.setOnClickListener(new View.OnClickListener() {		
			@Override
			public void onClick(View v) {
				Intent intent = new Intent();
				intent.putExtra("key", "value_data_button");
				setResult(RESULT_OK, intent);
				finish();
			}
		});        
    }


    //系统返回键事件处理函数
	@Override
	public void onBackPressed() {
		Intent intent = new Intent();
		intent.putExtra("key", "value_data_backpressed");
		setResult(RESULT_OK, intent);
		finish();
	}
}