Android清除中间活动

Question

I have 5 Activities,

A - Base Activity

B,C,D - Normal Activities

E - Final Activity

ABCDE

I navigate from A to B to C to D, D takes me to E. I want behaviour : if I press back button on D it should take me to C , back button from C should take me to B down to A. But if I have moved to Activity E from D, I want the back button from E it should take me to A skipping B,C and D.

Answer 1

In E :

@Override
public void onBackPressed() {
    Intent intent = new Intent(this, ActivityA.class);
    intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP) | Intent.FLAG_ACTIVITY_SINGLE_TOP);
    startActivity(intent);
}

This will go back to A , finishing B , C , D and E .

Using FLAG_ACTIVITY_SINGLE_TOP will ensure that you return to the existing instance of A . If you want to also finish the existing instance of A and create a new one to return to, simply remove FLAG_ACTIVITY_SINGLE_TOP .

Answer 2

You can use a static variable to track which activity you're coming from. Then override onBackPressed to check that variable and move to the appropriate activity. Something like:

public static Boolean skipActivities = false;

Then when you start activity E from D set it to true. For your activity E:

@Override
public void onBackPressed() {
    if (skipActivities){
        //start activity A, skipActivities should be reset to false also
    } else {
        super.onBackPressed();
    }
}

Answer 3

you can "group" you activities, by using affinity . So in Manifest file add android:taskAffinity="activity.normal" to activities B,C,D,E. And now you'll be able to finish all this group in any of this activities by calling finishAffinity() (instead of usual finish() ) in your case you can just add to E activity:

@Override
public void onBackPressed() {
    finishAffinity();
    super.onBackPressed();
}