How to manage startActivityForResult on Android?

Question

In my activity, I'm calling a second activity from the main activity by startActivityForResult. In my second activity there are some methods that finish this activity (maybe without result), however, just one of them return a result.

For example, from the main activity I call a second one. In this activity I'm checking some features of handset such as does it have a camera. If it doesn't have then I'll close this activity. Also, during preparation of MediaRecorder or MediaPlayer if a problem happens then I'll close this activity.

If its device has a camera and recording is done completely, then after recording a video if a user clicks on the done button then I'll send the result (address of the recorded video) back to main activity.

How do I check the result from the main activity?

Answer 1

If you want to update the user interface with activity result, you can't to use this.runOnUiThread(new Runnable() {} Doing this the UI won't refresh with new value. Instead, you can do this:

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

    if (resultCode == RESULT_CANCELED) {
        return;
    }

    global_lat = data.getDoubleExtra("LATITUDE", 0);
    global_lng = data.getDoubleExtra("LONGITUDE", 0);
    new_latlng = true;
}

@Override
protected void onResume() {
    super.onResume();

    if(new_latlng)
    {
        PhysicalTagProperties.this.setLocation(global_lat, global_lng);
        new_latlng=false;
    }
}

This seems silly but works pretty well.

Answer 2

For those who have problem with wrong requestCode in onActivityResult

If you are calling startActivityForResult() from your Fragment, the requestCode is changed by the Activity that owns the Fragment.

If you want to get the correct resultCode in your activity try this:

Change:

startActivityForResult(intent, 1); To:

getActivity().startActivityForResult(intent, 1);

Answer 3

Very common problem in android
It can be broken down into 3 Pieces
1 ) start Activity B (Happens in Activity A)
2 ) Set requested data (Happens in activity B)
3 ) Receive requested data (Happens in activity A)

1) startActivity B

Intent i = new Intent(A.this, B.class);
startActivity(i);

2) Set requested data

In this part, you decide whether you want to send data back or not when a particular event occurs.
Eg: In activity B there is an EditText and two buttons b1, b2.
Clicking on Button b1 sends data back to activity A
Clicking on Button b2 does not send any data.

Sending data

b1......clickListener
{
   Intent resultIntent = new Intent();
   resultIntent.putExtra("Your_key","Your_value");
   setResult(RES_CODE_A,resultIntent);
   finish();
}

Not sending data

b2......clickListener
    {
       setResult(RES_CODE_B,new Intent());
       finish();
    }

user clicks back button
By default, the result is set with Activity.RESULT_CANCEL response code

3) Retrieve result

For that override onActivityResult method

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

if (resultCode == RES_CODE_A) {

     // b1 was clicked 
   String x = data.getStringExtra("RES_CODE_A");

}
else if(resultCode == RES_CODE_B){

   // b2 was clicked

}
else{
   // back button clicked 
}
}

Answer 4

Example

To see the entire process in context, here is a supplemental answer. See my fuller answer for more explanation.

MainActivity.java

public class MainActivity extends AppCompatActivity {

    // Add a different request code for every activity you are starting from here
    private static final int SECOND_ACTIVITY_REQUEST_CODE = 0;

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

    // "Go to Second Activity" button click
    public void onButtonClick(View view) {

        // Start the SecondActivity
        Intent intent = new Intent(this, SecondActivity.class);
        startActivityForResult(intent, SECOND_ACTIVITY_REQUEST_CODE);
    }

    // This method is called when the second activity finishes
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        // check that it is the SecondActivity with an OK result
        if (requestCode == SECOND_ACTIVITY_REQUEST_CODE) {
            if (resultCode == RESULT_OK) { // Activity.RESULT_OK

                // get String data from Intent
                String returnString = data.getStringExtra("keyName");

                // set text view with string
                TextView textView = (TextView) findViewById(R.id.textView);
                textView.setText(returnString);
            }
        }
    }
}

SecondActivity.java

public class SecondActivity extends AppCompatActivity {

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

    // "Send text back" button click
    public void onButtonClick(View view) {

        // get the text from the EditText
        EditText editText = (EditText) findViewById(R.id.editText);
        String stringToPassBack = editText.getText().toString();

        // put the String to pass back into an Intent and close this activity
        Intent intent = new Intent();
        intent.putExtra("keyName", stringToPassBack);
        setResult(RESULT_OK, intent);
        finish();
    }
}

Answer 5

How to check the result from the main activity?

You need to override Activity.onActivityResult() then check its parameters:

• requestCode identifies which app returned these results. This is defined by you when you call startActivityForResult().
• resultCode informs you whether this app succeeded, failed, or something different
• data holds any information returned by this app. This may be null.

Answer 6

Complementing the answer from @Nishant,the best way to return the activity result is:

Intent returnIntent = getIntent();
returnIntent.putExtra("result",result);
setResult(RESULT_OK,returnIntent);
finish();

I was having problem with

new Intent();

Then I found out that the correct way is using

getIntent();

to get the current intent