startActivityForResult(Intent intent, int requestCode, Bundle options) how to retrieve the extra bundle option?

问题:

According to the Android documentation public void startActivityForResult (Intent intent, int requestCode, Bundle options).

I can not figure it out how to retrieve the extra bundle options that I am passing on the intent.

I want to pass an ArrayList with data as an extra bundle option when I am calling the startActivityForResult method.

Sample of code:

ArrayList<String> list = new ArrayList<>();         list.add("test1");         list.add("test2");          Bundle bundleOptions = new Bundle();         bundleOptions.putStringArrayList("key", list);  startActivityForResult(intent, 10, bundleOptions); 

Upon retrieving the data:

@Override     protected void onActivityResult(int requestCode, int resultCode, Intent data)  Bundle extras = data.getExtras(); 

Bundle extras does not contain the extra bundle that I am trying to pass. What I am missing and I can not retrieve the extra Bundle data that I am passing to the method?

I also tried with intent.putExtra("key", bundleOptions);, also with intent.putExtra("key", list); but with no success either and calling the method startActivityForResult(intent, 10); but again with no success.

I am sure that I am missing something does anybody know how to achieve this?

Thank you for your time and effort.

回答1:

Bundle extras does not contain the extra bundle that I am trying to pass.

Correct.

What I am missing

If you wish to retrieve a value using getExtras(), use putExtras() or individual putExtra() methods.

I can not retrieve the extra Bundle data that I am passing to the method?

That third parameter to startActivity()/startActivityForResult() are to pass options to Android itself, not to pass data to another activity.

I also tried with... intent.putExtra("key", list); but with no success either

In general, that works. For example, this sample app has worked since Android 1.0. The launcher activity uses putExtra() to add a string extra; the other activity uses getStringExtra() to get the value.

If you have continued problems using putExtra(), post a separate Stack Overflow question, where you supply your code for setting and retrieving the extra, along with a detailed description of your symptoms.

回答2:

I am sure that I am missing something

I suspect you misunderstand how the result thing works.

Let's suppose you have a HomeActivity and a SettingsActivity. HomeActivity starts a SettingsActivity with some parameters and wants to know some result. Here's how it works:

HomeActivity

This is how you open the SettingsActivity:

public void openSettings() {     Intent i = new Intent(this, SettingsActivity.class);     i.putExtra("myParam", 1);     startActivityForResult(i, 10); } 

This is the call you receive when SettingsActivity is closed:

public void onActivityResult(int requestCode, int resultCode, Intent data) {     if (requestCode == 10) {         if (resultCode == RESULT_OK) {             // Get result from the result intent.             String result = data.getStringExtra("myResult");              // Do something with result...         }     } } 

SettingsActivity

This is just the necessary bit. Reads the input, builds the output and closes itself. I hope it's enough for a demonstration.

public void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);      // Retrieve the parameter.     int param = getIntent().getIntExtra("myParam");      // Get a result somewhere.     String resultValue = "RESULT=" + param;      // Build a result intent and post it back.     Intent resultIntent = new Intent();     resultIntent.putExtra("myResult", resultValue);     setResult(RESULT_OK, resultIntent);     finish(); } 

See this http://developer.android.com/training/basics/intents/result.html.

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