Question

我正在使用tablayout并在onTabSelected（）中，我试图操纵同一活动中存在的视图的可见性，但它不起作用。

以下是代码：

@Override
public void onTabSelected(TabLayout.Tab tab) {
    viewPager.setCurrentItem(tab.getPosition());
    Log.v("tabSelectCount","count: "+ tab.getPosition());
    if(tab.getPosition()==0) {
        viewDetail.setVisibility(View.VISIBLE);
        viewWishlist.setVisibility(View.GONE);
        viewSwap.setVisibility(View.GONE);
    } else if(tab.getPosition()==1){
        viewDetail.setVisibility(View.GONE);
        viewWishlist.setVisibility(View.VISIBLE);
        viewSwap.setVisibility(View.GONE);
    } else {
        viewDetail.setVisibility(View.GONE);
        viewWishlist.setVisibility(View.GONE);
        viewSwap.setVisibility(View.VISIBLE);
    }
}

Answer 1

运行下面的代码，打开导航抽屉，在里面你会看到两个按钮，在导航抽屉打开时更改标签，并按照内部按钮可见性的变化进行操作。

Demo12：------------

public class Demo12 extends AppCompatActivity {

private ViewPager vp;
private TabLayout tl;
private ActionBarDrawerToggle mDrawerToggle;
private DrawerLayout dl;
private TabPagerAdapter adapter;
private Button b;
private Button b1;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.demo12);
    initialize();
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    return super.onCreateOptionsMenu(menu);
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {

    if (mDrawerToggle.onOptionsItemSelected(item)) {
        return true;
    }else {
        return super.onOptionsItemSelected(item);
    }
}

private void initialize() {

    tl = (TabLayout) findViewById(R.id.tl);
    tl.addTab(tl.newTab().setIcon(
            android.R.drawable.ic_dialog_email));
    tl.addTab(tl.newTab().setIcon(
            android.R.drawable.ic_dialog_dialer));
    tl.addTab(tl.newTab().setIcon(
            android.R.drawable.ic_dialog_alert));
    vp =
            (ViewPager) findViewById(R.id.vp);
    adapter = new TabPagerAdapter(getSupportFragmentManager(), tl.getTabCount(), this);
    vp.setAdapter(adapter);
    vp.setOffscreenPageLimit(1);

    b = (Button) findViewById(R.id.b);
    b.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Toast.makeText(getApplicationContext(),"Clicked",Toast.LENGTH_LONG).show();
        }
    });

    b1 = (Button) findViewById(R.id.b1);
    b1.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Toast.makeText(getApplicationContext(),"Clicked1",Toast.LENGTH_LONG).show();
        }
    });

    vp.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tl));
    tl.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {

        @Override
        public void onTabSelected(TabLayout.Tab tab) {
            vp.setCurrentItem(tab.getPosition(), true);
            if(tab.getPosition() == 0) {
                b.setVisibility(View.VISIBLE);
                b1.setVisibility(View.VISIBLE);
            }else if(tab.getPosition() == 1){
                b.setVisibility(View.VISIBLE);
                b1.setVisibility(View.GONE);
            }else{
                b.setVisibility(View.GONE);
                b1.setVisibility(View.VISIBLE);
            }
        }

        @Override
        public void onTabUnselected(TabLayout.Tab tab) {

        }

        @Override
        public void onTabReselected(TabLayout.Tab tab) {

        }

    });

    dl = (DrawerLayout) findViewById(R.id.dl);

    mDrawerToggle = new ActionBarDrawerToggle(this, dl, R.string.open,R.string.close) {

        public void onDrawerOpened(View drawerView) {
            invalidateOptionsMenu();
        }

        public void onDrawerClosed(View view) {
            invalidateOptionsMenu();
        }
    };

    getSupportActionBar().setDisplayHomeAsUpEnabled(true);
    getSupportActionBar().setHomeButtonEnabled(true);

    mDrawerToggle.setDrawerIndicatorEnabled(true);
    dl.addDrawerListener(mDrawerToggle);

}

@Override
protected void onPostCreate(Bundle savedInstanceState) {
    super.onPostCreate(savedInstanceState);
    mDrawerToggle.syncState();
}

@Override
public void onConfigurationChanged(Configuration newConfig) {
    super.onConfigurationChanged(newConfig);
    mDrawerToggle.onConfigurationChanged(newConfig);
}


}

TabPagerAdapter：---------------

public class TabPagerAdapter extends FragmentStatePagerAdapter {

private int tabCount;
private FragmentManager mFragmentManager;
private Context context;

public TabPagerAdapter(FragmentManager fm) {
    super(fm);
}

public TabPagerAdapter(FragmentManager fm, int numberOfTabs , Context context) {
    super(fm);
   mFragmentManager = fm;
   this.tabCount = numberOfTabs;
   this.context = context;
}

@Override
public Fragment getItem(int position) {
    switch (position) {
        case 0:
            return fragment_i.newInstance();
        case 1:
            return fragment_i.newInstance();
        case 2:
            return fragment_i.newInstance();
        default:
            return null;
    }
}


@Override
public Object instantiateItem(ViewGroup container, int position) {
    return super.instantiateItem(container, position);
}

@Override
public void destroyItem(ViewGroup container, int position, Object object) {
    super.destroyItem(container, position, object);

}

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

fragment_i：---------

public class fragment_i extends Fragment {


public fragment_i() {
}

public static fragment_i newInstance() {
    return new fragment_i();
}

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

@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
    super.onViewCreated(view, savedInstanceState);

}
}

fragment_i.xml：------------

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@android:color/holo_blue_light"
android:orientation="horizontal">

</LinearLayout>

demo12.xml：----------------

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/ll"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">

<android.support.design.widget.TabLayout
    android:id="@+id/tl"
    android:layout_width="match_parent"
    android:layout_height="50dp"
    app:tabMode="fixed"
    app:tabGravity="fill"
    android:background="?attr/colorPrimary"
    android:minHeight="?attr/actionBarSize"
    app:tabTextColor="#FFF"
    app:tabSelectedTextColor="@color/colorAccent"
    />

<android.support.v4.widget.DrawerLayout
    android:id="@+id/dl"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <android.support.v4.view.ViewPager
        android:id="@+id/vp"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:visibility="visible"
        app:layout_behavior="@string/appbar_scrolling_view_behavior"
        />

    <RelativeLayout
        android:layout_width="240dp"
        android:layout_height="match_parent"
        android:background="@android:color/holo_orange_light"
        android:layout_gravity="start">

        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Click"
            android:textSize="30sp"
            android:layout_centerInParent="true"
            android:background="@android:color/transparent"
            android:textColor="@android:color/holo_blue_light"
            android:id="@+id/b"/>

        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Click1"
            android:textSize="30sp"
            android:layout_centerInParent="true"
            android:background="@android:color/transparent"
            android:textColor="@android:color/holo_blue_light"
            android:layout_below="@id/b"
            android:id="@+id/b1"/>

    </RelativeLayout>

</android.support.v4.widget.DrawerLayout>

</LinearLayout>

setVisibility（）在tablayout中不起作用

1 个答案: