有片段添加搜索到操作欄

Question

我有一個選項卡式活動，並且我想在第二個選項卡中將搜索圖標添加到操作欄。我不希望它在第一個標籤中顯示。我是否需要將它添加到操作欄中，但只是在第二個選項卡中以某種方式誇大它？

Tab2.java

public class Tab2 extends Fragment { 

@Override 
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) { 
    View v =inflater.inflate(R.layout.tab_2,container,false); 
    return v; 
} 
} 

ViewPagerAdapter.java

public class ViewPagerAdapter extends FragmentStatePagerAdapter { 

CharSequence Titles[]; 
int NumbOfTabs; 


public ViewPagerAdapter(FragmentManager fm,CharSequence mTitles[], int mNumbOfTabsumb) { 
    super(fm); 

    this.Titles = mTitles; 
    this.NumbOfTabs = mNumbOfTabsumb; 

} 


@Override 
public Fragment getItem(int position) { 

    if(position == 0) 
    { 
     Tab1 tab1 = new Tab1(); 
     return tab1; 
    } 
    else 
    { 
     Ta2b tab2 = new Tab2(); 
     return tab2; 
    } 


} 


@Override 
public CharSequence getPageTitle(int position) { 
    return Titles[position]; 
} 


@Override 
public int getCount() { 
    return NumbOfTabs; 
} 
} 

menu_launch.xml

<menu xmlns:android="http://schemas.android.com/apk/res/android" 
xmlns:tools="http://schemas.android.com/tools" 
xmlns:app="http://schemas.android.com/apk/res-auto" 
tools:context=".LaunchActivity"> 

<item android:id="@+id/action_search" 
    android:title="@string/action_search" 
    android:src="@drawable/ic_action_search" 
    app:showAsAction="ifRoom" /> 

<item android:id="@+id/action_settings" 
    android:title="@string/action_settings" 
    android:orderInCategory="100" 
    app:showAsAction="never" /> 

</menu> 

LaunchActivity.java

public class LaunchActivity extends ActionBarActivity { 

Toolbar toolbar; 
ViewPager pager; 
ViewPagerAdapter adapter; 
SlidingTabLayout tabs; 
CharSequence Titles[]={"Tab 1","Tab 2"}; 
int Numboftabs =2; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_launch); 

    toolbar = (Toolbar) findViewById(R.id.tool_bar); 
    setSupportActionBar(toolbar); 

    adapter = new ViewPagerAdapter(getSupportFragmentManager(),Titles,Numboftabs); 

    pager = (ViewPager) findViewById(R.id.pager); 
    pager.setAdapter(adapter); 

    tabs = (SlidingTabLayout) findViewById(R.id.tabs); 
    tabs.setDistributeEvenly(true); 

    tabs.setCustomTabColorizer(new SlidingTabLayout.TabColorizer() { 
     @Override 
     public int getIndicatorColor(int position) { 
      return getResources().getColor(R.color.white); 
     } 
    }); 

    tabs.setViewPager(pager); 



} 


@Override 
public boolean onCreateOptionsMenu(Menu menu) { 
    getMenuInflater().inflate(R.menu.menu_launch, menu); 
    return true; 
} 

@Override 
public boolean onOptionsItemSelected(MenuItem item) { 
    int id = item.getItemId(); 

    if (id == R.id.action_settings) { 
     return true; 
    } 

    return super.onOptionsItemSelected(item); 
} 
} 

Answer 1

在PagerActivity

private MenuItem menuitemMy; 

... 
.. 

    pager = (ViewPager) findViewById(R.id.pager); 
    pager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() { 
     @Override 
     public void onPageSelected(int position) { 

      menuitemMy.setEnabled(true); 

      if(position == 0) { menuitemMy.setEnabled(false); } 

     } 

     @Override 
     public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) { 
     } 

     @Override 
     public void onPageScrollStateChanged(int state) { 


     } 
    }); 




... 
.. 

    @Override 
    public boolean onCreateOptionsMenu(Menu menu) { 
     super.onCreateOptionsMenu(menu); 
     getMenuInflater().inflate(R.menu.optionmenu, menu); 

     menuitemMy = menu.getItem(0); 

     return true; 
    }