Wie man zwischen Fragmenten durch Knöpfe

Question

wechselt Ich baue eine App. Ich habe meinen Übersichtsbildschirm als Fragmenthalter, wo ich Fragmente für die anderen Bildschirme verwenden möchte: Gruppen/Chat/Suche/Einstellungen. Unten ist mein OverviewActivity

public class Overview extends AppCompatActivity implements View.OnClickListener{ 
    ImageButton btn_search, btn_groups, btn_chat, btn_settings; 
    android.app.FragmentManager manager = getFragmentManager(); 
    android.app.FragmentTransaction transaction = manager.beginTransaction(); 
    SettingsFrg frg = new SettingsFrg(); 
    ChatFrg chfrg = new ChatFrg(); 
    GrouFrg grpfrg = new GrouFrg(); 
    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_overview); 
     loadUI(); 
     transaction.add(R.id.frg_holder,frg,"SRCHFRG"); 

    } 

    private void loadSettingsFrg() { 
     transaction.add(R.id.frg_holder,frg, "SRCHFRG"); 
     transaction.addToBackStack(null); 
     transaction.commit(); 
    } 

    private void loadUI() { 
     btn_chat = (ImageButton) findViewById(R.id.chatBtn); 
     btn_search = (ImageButton)findViewById(R.id.searchBtn); 
     btn_settings = (ImageButton)findViewById(R.id.settingsBtn); 
     btn_groups = (ImageButton) findViewById(R.id.groupsBtn); 
     btn_chat.setOnClickListener(this); 
     btn_groups.setOnClickListener(this); 
     btn_settings.setOnClickListener(this); 
     btn_search.setOnClickListener(this); 

    } 


    public void onClick(View view){ 
    switch (view.getId()){ 
     case R.id.chatBtn: 
      loadChatFrg(); 
      Toast.makeText(Overview.this, "go to chat", Toast.LENGTH_SHORT).show(); 
      break; 
     case R.id.searchBtn: 
      loadSettingsFrg(); 
      Toast.makeText(Overview.this, "go to search", Toast.LENGTH_SHORT).show(); 
      break; 
     case R.id.settingsBtn: 
      Toast.makeText(Overview.this, "go to settings", Toast.LENGTH_SHORT).show(); 
      break; 
     case R.id.groupsBtn: 
      loadGrouFrg(); 
      Toast.makeText(Overview.this, "go to groups", Toast.LENGTH_SHORT).show(); 
      break; 

    } 

    } 

    private void loadGrouFrg() { 

     transaction.replace(R.id.frg_holder,grpfrg,"GRPFRG"); 
     transaction.addToBackStack(null); 
     transaction.commit(); 
    } 

    private void loadChatFrg() { 
     transaction.replace(R.id.frg_holder,chfrg,"CHTFRG"); 
     transaction.addToBackStack(null); 
     transaction.commit(); 
    } 
} 

Bisher habe ich nur ein Fragment laden kann, wenn ich versuche, sie zu ersetzen, die App stürzt ab. Link zu git

Answer 1

Try verwenden diese Funktion wechseln Fragment

public void switchFragment(final Fragment fragment, final String tag) { 
    runOnUiThread(new Runnable() { 
     @Override 
     public void run() { 
      if (fragment != null) { 
       FragmentManager fragmentManager = getSupportFragmentManager(); 
       fragmentManager.beginTransaction().replace(R.id.frg_holder, fragment, tag).addToBackStack(null).commitAllowingStateLoss(); 
      } 
     } 
    }); 
}