How to prevent going back to the previous activity?

When the BACK button is pressed on the phone, I want to prevent a specific activity from returning to its previous one.

Specifically, I have login and sign up screens, both start a new activity called HomeScreen when successful login/signup occurs. Once HomeScreen is started, I want to prevent the users from being able to return to the login or sign up screens by pressing the BACK key.

I tried using Intent.FLAG_ACTIVITY_NO_HISTORY, but since the application has Facebook integration, when the 'Login with Facebook' is used, Facebook should return to the initial login screen, therefore I should keep a history of these activities.

I thought of overriding the behaviour of the BACK button on HomeScreen to directly finish an application when the button is pressed and I used

@Override
public void onBackPressed() {
	finish();
}

but that also does not work.

My suggestion would be to finish the activity that you don't want the users to go back to. For instance, in your sign in activity, right after you call startActivity, call finish(). When the users hit the back button, they will not be able to go to the sign in activity because it has been killed off the stack.

Following solution can be pretty useful in the usual login / main activity scenario or implementing a blocking screen.

To minimize the app rather than going back to previous activity, you can override onBackPressed() like this:

@Override
public void onBackPressed() {
    moveTaskToBack(true);
}

moveTaskToBack(boolean nonRoot) leaves your back stack as it is, just puts your task (all activities) in background. Same as if user pressed Home button.

Parameter boolean nonRoot - If false then this only works if the activity is the root of a task; if true it will work for any activity in a task.

I'm not sure exactly what you want, but it sounds like it should be possible, and it also sounds like you're already on the right track.

Here are a few links that might help:

https://stackoverflow.com/questions/4779954/disable-back-button-in-android

  MyActivity.java =>
    @Override
    public void onBackPressed() {
    
       return;
    }

https://stackoverflow.com/questions/6376708/how-can-i-disable-go-back-to-some-activity

  AndroidManifest.xml =>
<activity android:name=".SplashActivity" android:noHistory="true"/>

There are two solutions for your case, activity A starts activity B, but you do not want to back to activity A in activity B.

1. Removed previous activity A from back stack.

    Intent intent = new Intent(activityA.this, activityB.class);
    startActivity(intent);
    finish(); // Destroy activity A and not exist in Back stack

2. Disabled go back button action in activity B.

There are two ways to prevent go back event as below,

1. Recommend approach

   @Override public void onBackPressed() { }

2）Override onKeyDown method

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    if(keyCode==KeyEvent.KEYCODE_BACK) {
        return false;
    }
    return super.onKeyDown(keyCode, event);
}

Hope that it is useful, but still depends on your situations.

Since there are already many great solutions suggested, ill try to give a more dipictive explanation.

> How to skip going back to the previous activity?

Remove the previous Activity from Backstack. Simple

> How to remove the previous Activity from Backstack?

Call finish() method

The Normal Flow:

All the activities are stored in a Stack known as Backstack.
When you start a new Activity(startActivity(...)) then the new Activity is pushed to top of the stack and when you press back button the Activity is popped from the stack.
One key point to note is that when the back button is pressed then finish(); method is called internally. This is the default behavior of onBackPressed() method.

So if you want to skip Activity B?

> ie A<--- C

Just add finish(); method after your startActvity(...) in the Activity B

Intent i = new Intent(this, C.class);
startActivity(i);
finish();

finish() gives you method to close current Activity not whole application. And you better don't try to look for methods to kill application. Little advice.

Have you tried conjunction of Intent.FLAG_ACTIVITY_EXCLUDE_FROM_RECENTS | Intent.FLAG_ACTIVITY_NO_HISTORY? Remember to use this flags in Intent starting activity!

Put finish() just after

Intent i = new Intent(Summary1.this,MainActivity.class);
            startActivity(i);
finish();

If you don't want to go back to all the activities on your application, you can use

android:launchMode="singleTask"

Learn more here: http://developer.android.com/guide/topics/manifest/activity-element.html

paulsm4's answer is the correct one. If in onBackPressed() you just return, it will disable the back button. However, I think a better approach given your use case is to flip the activity logic, i.e. make your home activity the main one, check if the user is signed in there, if not, start the sign in activity. The reason is that if you override the back button in your main activity, most users will be confused when they press back and your app does nothing.

This method is working fine

Intent intent = new Intent(Profile.this, MainActivity.class); 
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK); 
startActivity(intent);

@Override
public void onBackPressed() {
}

When you create onBackPressed() just remove super.onBackPressed();and that should work

Just override the onKeyDown method and check if the back button was pressed.

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) 
{
	if (keyCode == KeyEvent.KEYCODE_BACK) 
	{
		//Back buttons was pressed, do whatever logic you want
	}

	return false;
}

Put

finish();

immediately after ActivityStart to stop the activity preventing any way of going back to it. Then add

onCreate(){
    getActionBar().setDisplayHomeAsUpEnabled(false);
    ...
}

to the activity you are starting.