如何獲取已選擇的片段

我正在使用片段創建選項卡應用程序。如何獲取已選擇的片段

我已經成功創建了選項卡，但是現在我需要在選擇特定片段時創建一個對象。例如當我選擇SettingsTab時，我需要調用Test class中定義的函數。類似地摧毀

// SettingsTab 
package com.example.sensorspositioningn; 

import android.app.Fragment; 
import android.os.Bundle; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 

public class SettingsTab extends Fragment { 

    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { 
     // Inflate the layout for this fragment 
     return inflater.inflate(R.layout.settingstab, container, false); 

    } 
}

這裏是mainActivity代碼：

protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 


     appContext = getApplicationContext(); 

     //ActionBar 
     ActionBar actionbar = getActionBar(); 
     actionbar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS); 

     ActionBar.Tab Tab1= actionbar.newTab().setText("Tab1"); 
     ActionBar.Tab Tab2= actionbar.newTab().setText("Tab2"); 
     ActionBar.Tab Tab3= actionbar.newTab().setText("Tab3"); 
     ActionBar.Tab SettingsTab = actionbar.newTab().setText("Settings"); 

     Fragment Tab1F= new Tab1(); 
     Fragment Tab2F= new Tab2(); 
     Fragment Tab3F= new Tab3(); 
     Fragment mSettingsFragment = new SettingsTab(); 

     Tab1.setTabListener(new MyTabsListener(Tab1F)); 
     Tab1.setTabListener(new MyTabsListener(Tab2F)); 
     Tab1.setTabListener(new MyTabsListener(Tab3F)); 
     SettingsTab.setTabListener(new MyTabsListener(mSettingsFragment)); 

     actionbar.addTab(Tab1); 
     actionbar.addTab(Tab2); 
     actionbar.addTab(Tab3); 
     actionbar.addTab(SettingsTab); 


    } 
protected void onSaveInstanceState(Bundle outState) { 
     super.onSaveInstanceState(outState); 
     outState.putInt("tab", getActionBar().getSelectedNavigationIndex()); 
    } 

class MyTabsListener implements ActionBar.TabListener { 
     public Fragment fragment; 

     public MyTabsListener(Fragment fragment) { 
      this.fragment = fragment; 
     } 


     public void onTabReselected(Tab tab, FragmentTransaction ft) { 
      Toast.makeText(MainActivity.appContext, "Reselected!", Toast.LENGTH_LONG).show(); 
     } 


     public void onTabSelected(Tab tab, FragmentTransaction ft) { 
      ft.replace(R.id.fragment_container, fragment); 




     } 


     public void onTabUnselected(Tab tab, FragmentTransaction ft) { 
      ft.remove(fragment); 


     } 
    }

來源

2013-06-20 Dawood Awan

請解釋你的問題，明確你想要什麼？ –

在你ActionBar.TabListener你可以這樣做 - （我假設你所需要的對象是在Activity），我發現這個

class MyTabsListener implements ActionBar.TabListener { 
    public Fragment fragment; 

    public MyTabsListener(Fragment fragment) { 
     this.fragment = fragment; 
    } 


    public void onTabReselected(Tab tab, FragmentTransaction ft) { 
     Toast.makeText(MainActivity.appContext, "Reselected!", Toast.LENGTH_LONG).show(); 
    } 


    public void onTabSelected(Tab tab, FragmentTransaction ft) { 
     ft.replace(R.id.fragment_container, fragment); 

     if(fragment instanceof SettingsTab) { 
      // Create your object, call your function 
     } 
    } 


    public void onTabUnselected(Tab tab, FragmentTransaction ft) { 
     ft.remove(fragment); 

     if(fragment instanceof SettingsTab) { 
      // Destroy your object 
     } 
    } 
}

來源

2013-09-26 11:33:25 jaibatrik

試試這個

public void onTabSelected(Tab tab, FragmentTransaction ft) { 
     ft.replace(R.id.fragment_container, fragment); 

     if(fragment instanceof SettingsTab){ 
      doSettingsMethod(); 
     } 

     if(fragment instanceof Tab1){ 
      doOtherMethod1(); 
     } 

     if(fragment instanceof Tab2){ 
      doOtherMethod2(); 
     } 

     if(fragment instanceof Tab3){ 
      doOtherMethod3(); 
     } 
    }

你也可以改變這種方式TabListener類。至於我這是一個更好的設計。

class MyTabsListener implements ActionBar.TabListener { 
    public Fragment fragment; 
    private final Runnable onSelect; 

    public MyTabsListener(Fragment fragment) { 
     this.fragment = fragment; 
     this.onSelect = null; 
    } 

    public MyTabsListener(Fragment fragment, Runnable onSelect) { 
     this.fragment = fragment; 
     this.onSelect = onSelect; 
    } 


    public void onTabReselected(Tab tab, FragmentTransaction ft) { 
     Toast.makeText(MainActivity.appContext, "Reselected!", Toast.LENGTH_LONG).show(); 
    } 


    public void onTabSelected(Tab tab, FragmentTransaction ft) { 
     ft.replace(R.id.fragment_container, fragment); 
     if(onSelect != null){ 
      fragment.getActivity().runOnUiThread(onSelect); 
     } 
    } 


    public void onTabUnselected(Tab tab, FragmentTransaction ft) { 
     ft.remove(fragment); 


    } 
}

來源

2013-09-26 10:29:16

唯一的官方消息是在開發商site： http://developer.android.com/training/implementing-navigation/lateral.html

他們只是爲每個創建的片段添加參數，並在片段被選中時讀取參數。

來源

2013-10-02 13:37:37 Manu

默認情況下，如果您選擇一個選項卡，它將被突出顯示。如果要選擇明確表示，請使用onTabSelected（TabLayout.Tab選項卡）下給定的帶有指定選項卡索引位置的註釋代碼。該代碼將使用viewpager解釋關於選項卡選定位置的更改片段。

public class GalleryFragment extends Fragment implements TabLayout.OnTabSelectedListener 
{ 
private ViewPager viewPager;public ViewPagerAdapter adapter;private TabLayout tabLayout; 
@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container, 
         Bundle savedInstanceState) { 
View rootView = inflater.inflate(R.layout.fragment_gallery, container, false); 
viewPager = (ViewPager) rootView.findViewById(R.id.viewpager); 
adapter = new ViewPagerAdapter(getChildFragmentManager()); 
adapter.addFragment(new PaymentCardFragment(), "PAYMENT CARDS"); 
adapter.addFragment(new LoyaltyCardFragment(), "LOYALTY CARDS"); 
viewPager.setAdapter(adapter); 
tabLayout = (TabLayout) rootView.findViewById(R.id.tabs); 
    tabLayout.setupWithViewPager(viewPager); 
    tabLayout.setOnTabSelectedListener(this); 
} 

@Override 
public void onTabSelected(TabLayout.Tab tab) { 
    //This will be called 2nd when you select a tab or swipe using viewpager 
    final int position = tab.getPosition(); 
    Log.i("card", "Tablayout pos: " + position); 
    //TabLayout.Tab tabdata=tabLayout.getTabAt(position); 
    //tabdata.select(); 
    tabLayout.post(new Runnable() { 
     @Override 
     public void run() { 
      if (position == 0) { 
       PaymentCardFragment paymentCardFragment = getPaymentCardFragment(); 
       if (paymentCardFragment != null) { 
        VerticalViewpager vp = paymentCardFragment.mypager; 
        if(vp!=null) 
        { 
         //vp.setCurrentItem(position,true); 
         vp.setCurrentItem(vp.getAdapter().getCount()-1,true); 
        } 
        } 
      } 
      if (position == 1) { 
       LoyaltyCardFragment loyaltyCardFragment = getLoyaltyCardFragment(); 
       if (loyaltyCardFragment != null) { 
        VerticalViewpager vp = loyaltyCardFragment.mypager; 
        if(vp!=null) 
        { 
         vp.setCurrentItem(position); 
        } 
        } 
      } 
     } 
    }); 
} 

@Override 
public void onTabUnselected(TabLayout.Tab tab) { 
//This will be called 1st when you select a tab or swipe using viewpager 
} 
@Override 
public void onTabReselected(TabLayout.Tab tab) { 
    //This will be called only when you select the already selected tab(Ex: selecting 3rd tab again and again) 
} 
private PaymentCardFragment getLoyaltyCardFragment() { 
    Fragment f = adapter.mFragmentList.get(viewPager.getCurrentItem()); 

    if(f instanceof PaymentCardFragment) 
    { 
    return (PaymentCardFragment) f; 
    } 
    return null; 
} 
private LoyaltyCardFragment getPaymentCardFragment() { 
    Fragment f = adapter.mFragmentList.get(viewPager.getCurrentItem()); 
    if(f instanceof LoyaltyCardFragment) 
    { 
    return (LoyaltyCardFragment) f; 
    } 
    return null; 
} 
    class ViewPagerAdapter extends FragmentPagerAdapter { 
    public List<Fragment> mFragmentList = new ArrayList<>(); 
    private final List<String> mFragmentTitleList = new ArrayList<>(); 
    public void addFragment(Fragment fragment, String title) { 
    mFragmentList.add(fragment); 
    mFragmentTitleList.add(title); 
    } 
} 
}

來源

2016-02-01 10:05:08

如何獲取已選擇的片段

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