Finish an activity from another activity

问题:

I want to finish one activity from another activity, like:

In Activity [A], on button click, I am calling Activity [B] without finishing Activity [A].

Now in Activity [B], there are two buttons, New and Modify. When the user clicks on modify then pop an activity [A] from the stack with all the options ticked..

But when the user click on New button from Activity [B], then I will have to finish Activity [A] from the stack and reload that Activity [A] again into the stack.

I am trying it, but I am not able to finish Activity [A] from the stack... How can I do it?

I am using the code as:

From Activity [A]:

Intent GotoB = new Intent(A.this,B.class);
startActivityForResult(GotoB,1);

Another method in same activity

public void onActivityResult(int requestCode, int resultCode, Intent intent) {

    if (requestCode == 1)
    {
        if (resultCode == 1) {
            Intent i = getIntent();
            overridePendingTransition(0, 0);
            i.addFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION);
            finish();

            overridePendingTransition(0, 0);
            startActivity(i);
        }
    }
}

And in Activity [B], on button click:

setResult(1);
finish();

回答1:

1. Make your activity A in manifest file: launchMode = \"singleInstance\"

2. When the user clicks new, do FirstActivity.fa.finish(); and call the new Intent.

3. When the user clicks modify, call the new Intent or simply finish activity B.

FIRST WAY

In your first activity, declare one Activity object like this,

public static Activity fa;
onCreate()
{
    fa = this;
}

now use that object in another Activity to finish first-activity like this,

onCreate()
{
    FirstActivity.fa.finish();
}

SECOND WAY

While calling your activity FirstActivity which you want to finish as soon as you move on, You can add flag while calling FirstActivity

intent.addFlags(Intent.FLAG_ACTIVITY_NO_HISTORY);

But using this flag the activity will get finished evenif you want it not to. and sometime onBack if you want to show the FirstActivity you will have to call it using intent.

回答2:

That you can do, but I think you should not break the normal flow of activity. If you want to finish you activity then you can simply send a broadcast from your activity B to activity A.

Create a broadcast receiver before starting your activity B:

BroadcastReceiver broadcastReceiver = new BroadcastReceiver() {

    @Override
    public void onReceive(Context arg0, Intent intent) {
        String action = intent.getAction();
        if (action.equals(\"finish_activity\")) {
            finish();
            // DO WHATEVER YOU WANT.
        }
    }
};
registerReceiver(broadcastReceiver, new IntentFilter(\"finish_activity\"));

Send broadcast from activity B to activity A when you want to finish activity A from B

Intent intent = new Intent(\"finish_activity\");
sendBroadcast(intent);

I hope it will work for you...

回答3:

This is a fairly standard communication question. One approach would be to use a ResultReceiver in Activity A:

Intent GotoB=new Intent(A.this,B.class);
GotoB.putExtra(\"finisher\", new ResultReceiver(null) {
    @Override
    protected void onReceiveResult(int resultCode, Bundle resultData) {
        A.this.finish();
    }
});
startActivityForResult(GotoB,1);

and then in Activity B you can just finish it on demand like so:

((ResultReceiver)getIntent().getExtra(\"finisher\")).send(1, new Bundle());

Try something like that.

回答4:

There is one approach that you can use in your case.

Step1: Start Activity B from Activity A

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

Step2: If the user clicks on modify button start Activity A using the FLAG_ACTIVITY_CLEAR_TOP.Also, pass the flag in extra.

Intent i = new Intent(B.this, A.class);
i.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
i.putExtra(\"flag\", \"modify\");
startActivity(i);
finish();

Step3: If the user clicks on Add button start Activity A using the FLAG_ACTIVITY_CLEAR_TOP.Also, pass the flag in extra. FLAG_ACTIVITY_CLEAR_TOP will clear all the opened activities up to the target and restart if no launch mode is defined in the target activity

Intent i = new Intent(B.this, A.class);
i.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
i.putExtra(\"flag\", \"add\");
startActivity(i);
finish();

Step4: Now onCreate() method of the Activity A, need to retrieve that flag.

String flag = getIntent().getStringExtra(\"flag\");
if(flag.equals(\"add\")) {
    //Write a code for add
}else {
    //Write a code for modifying
}

回答5:

See my answer to Stack Overflow question Finish All previous activities.

What you need is to add the Intent.FLAG_CLEAR_TOP. This flag makes sure that all activities above the targeted activity in the stack are finished and that one is shown.

Another thing that you need is the SINGLE_TOP flag. With this one you prevent Android from creating a new activity if there is one already created in the stack.

Just be wary that if the activity was already created, the intent with these flags will be delivered in the method called onNewIntent(intent) (you need to overload it to handle it) in the target activity.

Then in onNewIntent you have a method called restart or something that will call finish() and launch a new intent toward itself, or have a repopulate() method that will set the new data. I prefer the second approach, it is less expensive and you can always extract the onCreate logic into a separate method that you can call for populate.

回答6:

I\'ve just applied Nepster\'s solution and works like a charm. There is a minor modification to run it from a Fragment.

To your Fragment

// sending intent to onNewIntent() of MainActivity
Intent intent = new Intent(getActivity(), MainActivity.class);
intent.putExtra(\"transparent_nav_changed\", true);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(intent);

And to your OnNewIntent() of the Activity you would like to restart.

// recreate activity when transparent_nav was just changed
if (getIntent().getBooleanExtra(\"transparent_nav_changed\", false)) {
    finish(); // finish and create a new Instance
    Intent restarter = new Intent(MainActivity.this, MainActivity.class);
    startActivity(restarter);
}

回答7:

I think i have the easiest approach... on pressing new in B..

Intent intent = new Intent(B.this, A.class);
intent.putExtra(\"NewClicked\", true);
 intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(intent);

and in A get it

  if (getIntent().getBooleanExtra(\"NewClicked\", false)) {
        finish();// finish yourself and make a create a new Instance of yours.
      Intent intent = new Intent(A.this,A.class);
      startActivity(intent);
    }

回答8:

Start your activity with request code :

StartActivityForResult(intent,1003);

And you can close it from any other activity like this :

FinishActivity(1003);

回答9:

I know this is an old question, a few of these methods didn\'t work for me so for anyone looking in the future or having my troubles this worked for me

I overrode onPause and called finish() inside that method.

回答10:

I want you to look at the sharing here. It works completely and without trouble.

Activity a

public static ActivityA instance = null;
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    instance = this;
}

@Override
public void finish() {
    super.finish();
    instance = null;
}

Activity b

public void onCreate(Bundle savedInstanceState) {
    if(ActivityA.instance != null) {
        try {  
            ActivityA.instance.finish(); 
        } catch (Exception e) {}
    }
}

回答11:

First call startactivity() than use finish()