添加和替换片段，在android中不能正常工作

Question

我尝试了android碎片，并且我无法理解这一点;请帮助

public class MainActivity extends FragmentActivity { 
    private static final String TAG = "MyActivity"; 
    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 

     if (findViewById(R.id.fragment_container) !=null) { 
      if(savedInstanceState!=null){ 
       return ; 
      } 
      ArticleFragment first_fragment = new ArticleFragment(); 
      HeadlineFragment second_fragment = new HeadlineFragment(); 
      first_fragment.setArguments(getIntent().getExtras()); 
      second_fragment.setArguments(getIntent().getExtras()); 
      FragmentTransaction manager=getSupportFragmentManager().beginTransaction(); 
      manager.add(R.id.fragment_container, first_fragment,"first"); 
      manager.add(R.id.yo, second_fragment,"second"); 
      manager.commit(); 
     } 
    } 

现在我想删除second_fragment在一个按钮按下并替换为另一个。所以我试过这个

if(getSupportFragmentManager().findFragmentByTag("second")!=null) { 
        Log.d(TAG,"found"); 
        abc newFragment = new abc(); 
        Bundle args = new Bundle(); 
        FragmentTransaction transaction = getSupportFragmentManager().beginTransaction(); 
        transaction.remove(getSupportFragmentManager().findFragmentByTag("second")); 
        transaction.add(R.id.fragment_container,newFragment,"third"); 
        transaction.addToBackStack(null); 
        transaction.commit(); 
       } 

但是当我再次按下该按钮时，条件通过。 这里有什么问题？

Answer 1

请勿删除和添加。简单地用新的替换第二个片段。你会完成的。