从另一个活动中完成一个活动

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.

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...

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.

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.

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
}

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);
}

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);
}

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.

First call startactivity() then use finish()

Start your activity with request code :

StartActivityForResult(intent,1234);

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

finishActivity(1234);