cannot understand the finish method android

Question

protected void onCreate(Bundle savedInstanceState) {
  //if user is already logged in open the profile activity directly
  if (SharedPrefManager.getInstance(this).isLoggedIn()) {
    finish();
    startActivity(new Intent(this, Home.class));
  }
  buttonSignIn.setOnClickListener(this);
  buttonSignUp.setOnClickListener(this);
}

Can someone please explain to me why is finish() called before launching the Home.class if the user is already logged in. I'm trying to go through some source code and not able to understand this.

Program execution does not stop after you call finish(). It just means "finish this activity, and then start the Home activity". — Ken Wolf, Sep 20 '17 at 08:46
What if i have some line of codes in between finish and startActivity? — Grace Jochu, Sep 20 '17 at 08:57
found what i exactly needed after https://stackoverflow.com/questions/18111245/is-it-a-good-idea-to-call-finish-after-starting-a-new-activity-in-android Thank you guys — Grace Jochu, Sep 20 '17 at 09:02

Raja · Answer 1 · 2017-09-20T09:17:46.007

0

After finish() you can't get context from the activity.

You have to start activity like this:

if (SharedPrefManager.getInstance(this).isLoggedIn()) {            
        startActivity(new Intent(this, Home.class));
        finish();
    }

edited Sep 20 '17 at 09:17

answered Sep 20 '17 at 08:49

Raja

2,775
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So is it a better idea to call finish after starting a newactivty? – Grace Jochu Sep 20 '17 at 08:58
yes, its right way – Raja Sep 20 '17 at 09:08

score 0 · Answer 2 · answered Sep 20 '17 at 08:54

0

simply when you call finish(); its more like an intent which do this :

Intent intent = new Intent(whereYouareActivity.this , mainActivity.class};
startActivity(intent);

answered Sep 20 '17 at 08:54

White Druid

295
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12

score 0 · Answer 3 · answered Sep 20 '17 at 08:54

when you finish an activity, the activity gets destroyed but not the process. This is an important aspect of Android programming and is important to understand how it's different from other platforms.

And you can finish your activity by adding these lines :-

if (SharedPrefManager.getInstance(this).isLoggedIn()) {            
        startActivity(new Intent(this, Home.class));
        finish();
    }

score 0 · Answer 4 · answered Sep 20 '17 at 09:40

0

By calling finish() you actively close your current Activity. This prevents your activity from being shown again when the user presses the back button.

answered Sep 20 '17 at 09:40

Ombrax

95
7

cannot understand the finish method android

4 Answers4