Android的GetExtra无法使用

Question

I'm new to the android world so I started practicing by create a "Keep" application. So as you imagine I can add notes. The problem is here I go my main activity here :

@Override
protected void onResume() {
    super.onResume();
    if (newNote) {
        newNote = false;
      findViewById(R.id.note)).setText(intentNewNote.getStringExtra("toto"));
    }
}

public void addNotes(View view) {
    newNote = true;
    intentNewNote = new Intent(this, newNote.class);
    startActivity(intentNewNote);
}

So I have a button that call onClick addNotes and here is the newNote class -

 @Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    this.setContentView(R.layout.new_note);
    intent = this.getIntent();
}

 @Override
protected void onDestroy() {
    intent.putExtra("toto", "tototookiklojlojlllllllllllllllllllllllllllllto");
    super.onDestroy();
}

The toto Extra is a test but it can't be printed and this way it work

 @Override
protected void onResume() {
    super.onResume();
    if (newNote) {
        newNote = false;
        intentNewNote.putExtra("toto", "dzazda");
        ((TextView) findViewById(R.id.note)).setText(intentNewNote.getStringExtra("toto"));
    }
}

So when I put the extra in another activity it don't work the only explanation is that the intent I get on the addNotes class is not the same. Has someone an idea ?

Thank you.

Answer 1

Are you using putExtra in a way to save your data? I am very confused in what you are trying to do.

In order to create a Keep type of application, you will need some sort of database/server. Look at Parse or Firebase.

Answer 2

I am trying to understand what your are doing and I believe you are trying to return some information from your second activity, but you are using the same intent that you receive. The way it works on android is this :

From your FirstActivity call the SecondActivity using startActivityForResult() method

For example:

Intent i = new Intent(this, SecondActivity.class); startActivityForResult(i, 1); In your SecondActivity set the data which you want to return back to FirstActivity. If you don't want to return back, don't set any.

For example: In secondActivity if you want to send back data:

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

If you don't want to return data:

Intent returnIntent = new Intent();
setResult(Activity.RESULT_CANCELED, returnIntent);
finish();

Edited

Now in your FirstActivity class write following code for the onActivityResult() method.

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

if (requestCode == 1) {
    if(resultCode == Activity.RESULT_OK){
        String result=data.getStringExtra("result");
    }
    if (resultCode == Activity.RESULT_CANCELED) {
        //Write your code if there's no result
    }
}
}//onActivityResult