Android-如何直接转到后退堆栈中的上一个活动，而忽略片段后退堆栈或当前活动中的剩余片段？

Question

There are questions regarding back stack and fragmentManager but I didn't find any that have this similar use case.

So Here is my use case: on a tablet, I have the main activity on the left that acts as a navigation page, and fragments showing on the right when users click on things on the left. Eg when clicking on General , the general page will be shown on the right. Let's say I navigate from Homepage to this Settings activity which has General and other settings, I show the General page on the right as default on the tablet (so that the right part won't be blank), and when I click on the back button, I want to go back directly to Homepage instead of showing the blank right part. I fixed this by:

override fun onBackPressed() {
    //some code
    if (isTabletLayout && supportFragmentManager.backStackEntryCount == 1) {
        supportFragmentManager.popBackStack()
    }
    super.onBackPressed()
    //some other code
}

However, even if I do this, I will see the right part flashes to blank and then I was shown the previous activity (in the example, the Homepage )

Now I'm wondering if I can just ignore that last fragment or delete the fragment back stack when there is only one left and directly show the previous activity?

Thanks in advance.

Answer 1

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

Just call finish() on onBackPressed() method.

Answer 2

There's a way around by just calling finish();

However you shouldn't use your main activity as a navigation Tab. That's straight up bad UI and will lead to a bad UX.

Rearrange your UI now and avoid bigger problems in the future.