How to manage activity with startActivityForResult

Question

I got a situation like this:

Activity A --> B --> C --> D, when D finished, I have to refresh ActivityA to display what I input in ActivityB , ActivityC and Activity

Answer 1

You can pass on the "target" Activity for the required results from one Activity to the next with Intent.FLAG_ACTIVITY_FORWARD_RESULT. If you start ActivityC for example:

@OnClick(R.id.btn_two)
public void toActivityC(){
    Intent intent = new Intent();
    intent.setClass(this, ActivityC.class);
    intent.setFlag( Intent.FLAG_ACTIVITY_FORWARD_RESULT );
    startActivityForResult(intent, 2);
}

This way the new activity can call setResult(int) and have that result sent back to the reply target of the original activity.

(quoted from Intent documentation)

In your case this means also that each Activity (B and C) has to pass the data which has been collected so far along with the Intent used for starting the next Activity. Finally, ActivityD can call setResult() to transmit the data to ActivityA.

EDIT (1) I'm adding some code to demonstrate how to react if the user presses the BACK key. For simplicity's sake, let's assume that the user would only decide to press BACK while in ActivityD.

EDIT (2) Note that Intent.putExtra() can take a Bundle, so you can pass a whole Bundle with all your data along instead of transferring all the values one by one to the new Intent. Using one Bundle extra instead of several other extras can result in less lines of code.

The xml files

activity_a.xml

activity_b.xml

activity_c.xml

activity_d.xml

The activities

ActivityA

public class ActivityA extends AppCompatActivity
{
    static final int REQUEST_CODE = 42;

    static final String KEY_RESULT_FROM_B = "result_b";
    static final String KEY_RESULT_FROM_C = "result_c";
    static final String KEY_RESULT_FROM_D = "result_d";

    private TextView tvResult1, tvResult2, tvResult3;
    private Button btnGetResults;

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

    tvResult1 = (TextView) findViewById(R.id.tv_result1);
    tvResult2 = (TextView) findViewById(R.id.tv_result2);
    tvResult3 = (TextView) findViewById(R.id.tv_result3);

    btnGetResults = (Button) findViewById(R.id.btn_get_results);
    btnGetResults.setOnClickListener(new View.OnClickListener()
    {
        @Override
        public void onClick(View v)
        {
            startActivityForResult(new Intent(ActivityA.this, ActivityB.class), REQUEST_CODE);
        }
    });

}


@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data)
{
    if (REQUEST_CODE == requestCode)
    {
        if (resultCode == RESULT_OK)
        {
            tvResult1.setText(data.getStringExtra(KEY_RESULT_FROM_B));
            tvResult2.setText(data.getStringExtra(KEY_RESULT_FROM_C));
            tvResult3.setText(data.getStringExtra(KEY_RESULT_FROM_D));
            btnGetResults.setEnabled(false);
        }
        else
        {
            Toast.makeText(ActivityA.this, "no result", Toast.LENGTH_SHORT).show();
            // do something else
        }
    }
}
}

ActivityB

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

    TextView tvResult = (TextView) findViewById(R.id.tv_result);
    final String result = tvResult.getText().toString();

    Button btnGetResults = (Button) findViewById(R.id.btn_get_results);
    btnGetResults.setOnClickListener(new View.OnClickListener()
    {
        @Override
        public void onClick(View v)
        {
            Intent intent = new Intent(ActivityB.this, ActivityC.class);
            intent.setFlags(Intent.FLAG_ACTIVITY_FORWARD_RESULT);

            intent.putExtra(ActivityA.KEY_RESULT_FROM_B, result);
            startActivity(intent);
            finish();
        }
    });
}

ActivityC

public class ActivityC extends AppCompatActivity
{
    static final String IS ="is";
    static final String IS_NOT = "is not";

    private CheckBox cbResult;

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

    cbResult = (CheckBox) findViewById(R.id.cb_result);
    cbResult.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener()
    {
        @Override
        public void onCheckedChanged(CompoundButton buttonView, boolean isChecked)
        {
            buttonView.setText(isChecked ? IS : IS_NOT);
        }
    });

    String previousResult = getIntent().getStringExtra(ActivityA.KEY_RESULT_FROM_C);
    cbResult.setChecked( ! IS_NOT.equals(previousResult) );

    final String result1 = getIntent().getStringExtra(ActivityA.KEY_RESULT_FROM_B);

    Button btnGetResults = (Button) findViewById(R.id.btn_get_results);
    btnGetResults.setOnClickListener(new View.OnClickListener()
    {
        @Override
        public void onClick(View v)
        {
            Intent intent = new Intent(ActivityC.this, ActivityD.class);
            intent.setFlags(Intent.FLAG_ACTIVITY_FORWARD_RESULT);
            intent.putExtra(ActivityA.KEY_RESULT_FROM_B, result1);
            String result2= cbResult.getText().toString();
            intent.putExtra(ActivityA.KEY_RESULT_FROM_C, result2);
            startActivity(intent);
            finish();
        }
    });
}
}

ActivityD

public class ActivityD extends AppCompatActivity
{
    static final String POSSIBLE = "possible :)";
    static final String COMPLICATED = "complicated";

    private String result1, result2;

    private TextView tvResult;

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

    tvResult = (TextView) findViewById(R.id.tv_result);
    result1 = getIntent().getStringExtra(ActivityA.KEY_RESULT_FROM_B);
    result2 = getIntent().getStringExtra(ActivityA.KEY_RESULT_FROM_C);

    if (ActivityC.IS.equals(result2))
    {
        tvResult.setText(POSSIBLE);
    }
    else
    {
        tvResult.setText(COMPLICATED);
    }


    Button btnSendResults = (Button) findViewById(R.id.btn_send_results);
    btnSendResults.setOnClickListener(new View.OnClickListener()
    {
        @Override
        public void onClick(View v)
        {
            Intent intent = new Intent();

            intent.putExtra(ActivityA.KEY_RESULT_FROM_B, result1);
            intent.putExtra(ActivityA.KEY_RESULT_FROM_C, result2);
            intent.putExtra(ActivityA.KEY_RESULT_FROM_D,  tvResult.getText().toString());
            setResult(RESULT_OK, intent);
            finish();
        }
    });
}

@Override
public void onBackPressed()
{
    // start ActivityC once more
    Intent intent = new Intent(ActivityD.this, ActivityC.class);
    intent.setFlags(Intent.FLAG_ACTIVITY_FORWARD_RESULT);

    intent.putExtra(ActivityA.KEY_RESULT_FROM_B, result1);
    // pass this to set the CheckBox like the user left it:
    intent.putExtra(ActivityA.KEY_RESULT_FROM_C, result2);
    startActivity(intent);
    finish();
}
}