Android – Explain RESULT_FIRST_USER

androidandroid-activityandroid-intent

I don't understand the meaning, value, or importance of RESULT_FIRST_USER, other than that my own result codes must be greater than 1. Will someone please explain it? RESULT_OK and RESULT_CANCELED make perfect sense to an english speaker. But what in the world of android is RESULT_FIRST_USER? All the documentations says about it is

Start of user-defined activity results.

Best Answer

The answer to the question is actually the combination of comments from @CommonsWare and @Chris. So, for the sake of progeny, I am going to consolidate the comments and make it available in one place.

Basically, there are two predefined constants for the requestCode and they are Activity.RESULT_OK and Activity.RESULT_CANCELLED. However, android developers can also set custom codes for their apps by using the offset Activity.RESULT_FIRST_USER. Doing so ensures that there are no clashes between constants set at the OS level and the app level.

Purely, my opinion, I think that the FIRST USER suffix is meant to refer to developers – just like how end consumer refers to consumers of a said product – who are the first users before the app users.

Below is an example of how you can use this offset,

public static final int MY_RESULT_CODE = Activity.RESULT_FIRST_USER + 1;

Related Solutions

Android Intents – Understanding Intent from OnActivityResult Parameters

When you call Activity.startActivityForResult(), you set the requestCode. Later, this request code is needed by onActivityResult() in order to determine what Activity is sending data to it. We don't need to supply requestCode again on setResult() because the requestCode is carried along.

The data is intent data returned from launched intent. We usually use this data when we set extras on the called intent.

Consider this example:

CALL SECOND ACTIVITY

Intent i = new Intent(MainActivity.this, CheckActivity.class);
startActivityForResult(i, REQUEST_CODE_CHECK);

ON SECOND ACTIVITY, SET INTENT RESULT

getIntent().putExtra("TADA", "bla bla bla");
setResult(RESULT_OK, getIntent());
finish();

BACK TO FIRST ACTIVITY, ONACTIVITYRESULT()

if(requestCode == REQUEST_CODE_CHECK && resultCode == RESULT_OK){
    text1.setText(data.getExtras().getString("TADA") );
}

There you go. You should now understand what is Intent data and how to set and fetch the value.

Best Answer

Related Solutions

Android Intents – Understanding Intent from OnActivityResult Parameters

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