조각이있는 작업 표시 줄 위로 탐색

조각이있는 작업 표시 줄 위로 탐색

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A , B , C 라는 세 개의 탭이있는 탭이있는 Actionbar / viewpager 레이아웃이 있습니다. 탭에서 C의 탭 (조각), 나는 또 다른 조각 말 조각 추가하고 D를 . 와

 DFragment f= new DFragment();
 ft.add(android.R.id.content, f, "");
 ft.remove(CFragment.this);
 ft.addToBackStack(null);
 ft.commit();

DFragment의 onResume에서 액션 바를 수정하여 버튼을 추가합니다.

ActionBar ab = getActivity().getActionBar();
ab.setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD);
ab.setDisplayHomeAsUpEnabled(true);
ab.setDisplayShowHomeEnabled(true);

이제 DFragment에서 하드웨어 (전화) 뒤로 버튼을 누르면 CFragment가 선택된 원래 Tabbed (ABC) 레이아웃으로 돌아갑니다. 액션 바 업 버튼으로이 기능을 어떻게 달성 할 수 있습니까?

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OnBackStackChangedListener이 코드를 구현 하고 조각 활동에 추가합니다.

@Override
public void onCreate(Bundle savedInstanceState) {
    //Listen for changes in the back stack
    getSupportFragmentManager().addOnBackStackChangedListener(this);
    //Handle when activity is recreated like on orientation Change
    shouldDisplayHomeUp();
}

@Override
public void onBackStackChanged() {
    shouldDisplayHomeUp();
}

public void shouldDisplayHomeUp(){
   //Enable Up button only  if there are entries in the back stack
   boolean canGoBack = getSupportFragmentManager().getBackStackEntryCount()>0;
   getSupportActionBar().setDisplayHomeAsUpEnabled(canGoBack);
}

@Override
public boolean onSupportNavigateUp() {
    //This method is called when the up button is pressed. Just the pop back stack.
    getSupportFragmentManager().popBackStack();
    return true;
}

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알았어. 단지 오버라이드 (override) onOptionsItemSelected을 활동을 주최하고, 예를 들면 가기 backstack 팝업

public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
        case android.R.id.home: {
            FragmentManager fm = getSupportFragmentManager();
            if (fm.getBackStackEntryCount() > 0) {
                fm.popBackStack();
                return true;
            }
            break;
        }
    }
    return super.onOptionsItemSelected(item);
}

전화 getActionBar().setDisplayHomeAsUpEnabled(boolean);와 getActionBar().setHomeButtonEnabled(boolean);의 onBackStackChanged()아래 답변에 설명 된대로.

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상위 활동이 하나 있고이 위로 버튼이 뒤로 버튼으로 작동하도록하려면 다음 코드를 사용할 수 있습니다.

이것을 기본 활동 클래스의 onCreate에 추가하십시오.

getSupportFragmentManager().addOnBackStackChangedListener(new FragmentManager.OnBackStackChangedListener() {
        @Override
        public void onBackStackChanged() {
            int stackHeight = getSupportFragmentManager().getBackStackEntryCount();
            if (stackHeight > 0) { // if we have something on the stack (doesn't include the current shown fragment)
                getSupportActionBar().setHomeButtonEnabled(true);
                getSupportActionBar().setDisplayHomeAsUpEnabled(true);
            } else {
                getSupportActionBar().setDisplayHomeAsUpEnabled(false);
                getSupportActionBar().setHomeButtonEnabled(false);
            }
        }

    });

다음과 같이 onOptionsItemSelected를 추가하십시오.

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
        case android.R.id.home:
            getSupportFragmentManager().popBackStack();
            return true;
     ....
 }

나는 일반적으로 이것을 항상 사용하고 꽤 합법적 인 것 같습니다

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뒤로 버튼과 같은 위로 버튼으로 돌아갈 수 있습니다.

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
        case android.R.id.home:
            super.onBackPressed();
            return true;
    }
    return super.onOptionsItemSelected(item);
}

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나는이 질문이 오래되었다는 것을 알고 있지만 (나 같은) 누군가도 그것을 필요로 할 수 있습니다.

활동이 AppCompatActivity를 확장 하는 경우 더 간단한 (2 단계) 솔루션을 사용할 수 있습니다.

1-홈이 아닌 프래그먼트를 추가 할 때마다 프래그먼트 트랜잭션을 커밋 한 직후 up 버튼 만 표시됩니다. 이렇게 :

    // ... add a fragment
    // Commit the transaction
    transaction.commit();

    getSupportActionBar().setDisplayHomeAsUpEnabled(true);

2-UP 버튼을 누르면 숨 깁니다.

@Override
public boolean onSupportNavigateUp() {
    getSupportActionBar().setDisplayHomeAsUpEnabled(false);        
    return true;
}

그게 다야.

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I used a combination of Roger Garzon Nieto's and sohailaziz's answers. My app has a single MainActivity, and fragments A, B, C that are loaded into it. My "home" fragment (A) implements OnBackStackChangedListener, and checks the size of the backStack; if it's less than one, then it hides the UP button. Fragments B and C always load the back button (in my design, B is launched from A, and C is launched from B). The MainActivity itself just pops the backstack on UP button tap, and has methods to show/hide the button, which the fragments call:

MainActivity:

public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
        // Respond to the action bar's Up/Home button
        case android.R.id.home:
            getSupportFragmentManager().popBackStack();
            return true;
    }
    return super.onOptionsItemSelected(item);
}

public void showUpButton() { getSupportActionBar().setDisplayHomeAsUpEnabled(true); }
public void hideUpButton() { getSupportActionBar().setDisplayHomeAsUpEnabled(false); }

fragmentA (implements FragmentManager.OnBackStackChangedListener):

public void onCreate(Bundle savedinstanceSate) {
    // listen to backstack changes
    getActivity().getSupportFragmentManager().addOnBackStackChangedListener(this);

    // other fragment init stuff
    ...
}

public void onBackStackChanged() {
    // enable Up button only  if there are entries on the backstack
    if(getActivity().getSupportFragmentManager().getBackStackEntryCount() < 1) {
        ((MainActivity)getActivity()).hideUpButton();
    }
}

fragmentB, fragmentC:

public void onCreate(Bundle savedinstanceSate) {
    // show the UP button
    ((MainActivity)getActivity()).showUpButton();

    // other fragment init stuff
    ...
}

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Kotlin:

class MyActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        ...
        supportFragmentManager.addOnBackStackChangedListener { setupHomeAsUp() }
        setupHomeAsUp()
    }

    private fun setupHomeAsUp() {
        val shouldShow = 0 < supportFragmentManager.backStackEntryCount
        supportActionBar?.setDisplayHomeAsUpEnabled(shouldShow)
    }

    override fun onSupportNavigateUp(): Boolean = 
        supportFragmentManager.popBackStack().run { true }

    ...
}

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This worked for me. Override onSupportNavigateUp and onBackPressed, for example (code in Kotlin);

override fun onBackPressed() {
    val count = supportFragmentManager.backStackEntryCount
    if (count == 0) {
        super.onBackPressed()
    } else {
        supportFragmentManager.popBackStack()
    }
}

override fun onSupportNavigateUp(): Boolean {
    super.onSupportNavigateUp()
    onBackPressed()
    return true
}

Now in the fragment, if you display the up arrow

activity.supportActionBar?.setDisplayHomeAsUpEnabled(true)

Clicking on it takes you back the previous activity.

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This is a very good and reliable solution: http://vinsol.com/blog/2014/10/01/handling-back-button-press-inside-fragments/

The guy has made an abstract fragment that handles the backPress behaviour and is switching between the active fragments using the strategy pattern.

For some of you there maybe a little drawback in the abstract class...

Shortly, the solution from the link goes like this:

// Abstract Fragment handling the back presses

public abstract class BackHandledFragment extends Fragment {
    protected BackHandlerInterface backHandlerInterface;
    public abstract String getTagText();
    public abstract boolean onBackPressed();

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if(!(getActivity()  instanceof BackHandlerInterface)) {
            throw new ClassCastException("Hosting activity must implement BackHandlerInterface");
        } else {
            backHandlerInterface = (BackHandlerInterface) getActivity();
        }
    }

    @Override
    public void onStart() {
        super.onStart();

        // Mark this fragment as the selected Fragment.
        backHandlerInterface.setSelectedFragment(this);
    }

    public interface BackHandlerInterface {
        public void setSelectedFragment(BackHandledFragment backHandledFragment);
    }
}   

And usage in the activity:

// BASIC ACTIVITY CODE THAT LETS ITS FRAGMENT UTILIZE onBackPress EVENTS 
// IN AN ADAPTIVE AND ORGANIZED PATTERN USING BackHandledFragment

public class TheActivity extends FragmentActivity implements BackHandlerInterface {
    private BackHandledFragment selectedFragment;

    @Override
    public void onBackPressed() {
        if(selectedFragment == null || !selectedFragment.onBackPressed()) {
            // Selected fragment did not consume the back press event.
            super.onBackPressed();
        }
    }

    @Override
    public void setSelectedFragment(BackHandledFragment selectedFragment) {
        this.selectedFragment = selectedFragment;
    }
}

참고URL : https://stackoverflow.com/questions/13086840/actionbar-up-navigation-with-fragments