How to finish current activity in Android

问题

I have an Android application. I am making a loading screen with a progress bar.

I entered a delay in the onCreate method. When the timer finishes, I want to finish the current activity and start a new one.

It just gives me an exception when it calls the finish() method.

public class LoadingScreen extends Activity{
    private LoadingScreen loadingScreen;
    Intent i = new Intent(this, HomeScreen.class);
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.loading);

        CountDownTimer timer = new CountDownTimer(10000, 1000) //10 second Timer
        {
            public void onTick(long l) 
            {

            }

            @Override
            public void onFinish() 
            {
                loadingScreen.finishActivity(0);
                startActivity(i);
            };
        }.start();
    }
}

How can I change the code so that it ends when the progress bar is done?

回答1:

If you are doing a loading screen, just set the parameter to not keep it in activity stack. In your manifest.xml, where you define your activity do:

<activity android:name=".LoadingScreen" android:noHistory="true" ... />

And in your code there is no need to call .finish() anymore. Just do startActivity(i);

There is also no need to keep a instance of your current activity in a separate field. You can always access it like LoadingScreen.this.doSomething() instead of private LoadingScreen loadingScreen;

回答2:

I tried using this example but it failed miserably. Every time I use to invoke finish()/ finishactivity() inside a handler, I end up with this menacing java.lang.IllegalAccess Exception. i'm not sure how did it work for the one who posed the question.

Instead the solution I found was that create a method in your activity such as

void kill_activity()
{ 
    finish();
}

Invoke this method from inside the run method of the handler. This worked like a charm for me. Hope this helps anyone struggling with "how to close an activity from a different thread?".

回答3:

You need to call finish() from the UI thread, not a background thread. The way to do this is to declare a Handler and ask the Handler to run a Runnable on the UI thread. For example:

public class LoadingScreen extends Activity{
    private LoadingScreen loadingScreen;
    Intent i = new Intent(this, HomeScreen.class);
    Handler handler;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        handler = new Handler();
        setContentView(R.layout.loading);

        CountDownTimer timer = new CountDownTimer(10000, 1000) //10seceonds Timer
        {
             @Override
             public void onTick(long l) 
             {

             }

             @Override
             public void onFinish() 
             {
                 handler.post(new Runnable() {
                     public void run() {
                         loadingScreen.finishActivity(0);
                         startActivity(i);
                     }
                 });
             };
        }.start();
    }
}

回答4:

Just call the finish() method:

context.finish();

回答5:

When you want start a new activity and finish the current activity you can do this:

API 11 or greater

Intent intent = new Intent(OldActivity.this, NewActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
startActivity(intent);

API 10 or lower

Intent intent = new Intent(OldActivity.this, NewActivity.class);
intent.setFlags(IntentCompat.FLAG_ACTIVITY_NEW_TASK | IntentCompat.FLAG_ACTIVITY_CLEAR_TASK);
startActivity(intent);

I hope this can help somebody =)

回答6:

You can also use: finishAffinity()

Finish this activity as well as all activities immediately below it in the current task that have the same affinity.

回答7:

I found many answers but not one is simple... I hope this will help you...

try{
    Intent intent = new Intent(CurrentActivity.this, NewActivity.class);
    startActivity(intent);
} finally {
    finish();
}

so, Very simple logic is here, as we know that in java we write code that has some chances of exception in a try block and handle that exception in catch block but in finally block we write code that has to be executed in any cost (Either the exception comes or not).

来源：https://stackoverflow.com/questions/5000787/how-to-finish-current-activity-in-android

标签

android

activity-finish