java Android TabLayout setOnTabSelectedListener 不起作用
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时间：2020-11-02 22:26:55 来源:igfitidea点击:
Android TabLayout setOnTabSelectedListener not working
提问by bernzkie
Let's say I have MainActivityclass where the TabLayoutand ViewPager are initialized with corresponding 4 pages.
假设我有一个MainActivity类，其中TabLayout和ViewPager 用相应的 4 页初始化。
MainActivity.class
主Activity.class
public class MainActivity extends AppCompatActivity {
private SectionsPagerAdapter mSectionsPagerAdapter;
private ViewPager mViewPager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());
// Set up the ViewPager with the sections adapter.
mViewPager = (ViewPager) findViewById(R.id.pager);
mViewPager.setAdapter(mSectionsPagerAdapter);
// TabLayout
TabLayout tabLayout = (TabLayout) findViewById(R.id.tab_layout);
tabLayout.setupWithViewPager(mViewPager);
}
public class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int position) {
// getItem is called to instantiate the fragment for the given page.
// Return a PlaceholderFragment (defined as a static inner class below).
// return PlaceholderFragment.newInstance(position + 1);
switch (position) {
case 0:
ActivityZero tab0 = new ActivityZero();
return tab0;
case 1:
ActivityOne tab1 = new ActivityOne();
return tab1;
case 2:
ActivityTwo tab2 = new ActivityTwo();
return tab2;
case 3:
ActivityThree tab3 = new ActivityThree();
return tab3;
default:
return null;
}
}
@Override
public int getCount() {
// Show 4 total pages.
return 4;
}
//Setting the ICON
private int[] imageResId = {
R.drawable.ic_zero
R.drawable.ic_one,
R.drawable.ic_two,
R.drawable.ic_three
};
@Override
public CharSequence getPageTitle(int position) {
Drawable image = ContextCompat.getDrawable(getApplicationContext(), imageResId[position]);
image.setBounds(0, 0, image.getIntrinsicWidth(), image.getIntrinsicHeight());
SpannableString sb = new SpannableString(" ");
ImageSpan imageSpan = new ImageSpan(image, ImageSpan.ALIGN_BOTTOM);
sb.setSpan(imageSpan, 0, 1, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
return sb;
}
}
}
Everything is working fine with the above code, but when I add setOnTabSelectedListenerin onCreatewith this:
一切工作正常与上面的代码，但是当我添加setOnTabSelectedListener在onCreate此：
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());
// Set up the ViewPager with the sections adapter.
mViewPager = (ViewPager) findViewById(R.id.pager);
mViewPager.setAdapter(mSectionsPagerAdapter);
// TabLayout
TabLayout tabLayout = (TabLayout) findViewById(R.id.tab_layout);
tabLayout.setupWithViewPager(mViewPager);
//This is what i'm trying to add
mViewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
tabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
@Override
public void onTabSelected(TabLayout.Tab tab) {
mViewPager.setCurrentItem(tab.getPosition());
tab.getIcon().setAlpha(255);
}
@Override
public void onTabUnselected(TabLayout.Tab tab) {
tab.getIcon().setAlpha(127);
}
@Override
public void onTabReselected(TabLayout.Tab tab) {
}
});
}
When I run, everything's work fine, but when I swipe to change the tab, the app is no longer responding and start to crash.
当我运行时，一切正常，但是当我滑动以更改选项卡时，应用程序不再响应并开始崩溃。
I'm trying to get the selected tab positionand set the iconwith setAlpha(127)on the selected page, but no luck.
我试图让所选择的选项卡position，并设置icon有setAlpha(127)上selected page，但没有运气。
NOTE:I'm using support library and my current API is 8.
注意：我正在使用支持库，我当前的 API 是 8。
UPDATE:
更新：
12-04 11:32:12.342 11884-11884/com.sample.app.mysampleapp E/InputEventReceiver: Exception dispatching input event.
12-04 11:32:12.342 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: Exception in MessageQueue callback: handleReceiveCallback
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: java.lang.NullPointerException
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at com.sample.app.mysampleapp.MainActivity.onTabUnselected(MainActivity.java:53)
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at android.support.design.widget.TabLayout.selectTab(TabLayout.java:867)
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at android.support.design.widget.TabLayout$TabLayoutOnPageChangeListener.onPageSelected(TabLayout.java:1759)
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at android.support.v4.view.ViewPager.dispatchOnPageSelected(ViewPager.java:1794)
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at android.support.v4.view.ViewPager.scrollToItem(ViewPager.java:569)
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at android.support.v4.view.ViewPager.setCurrentItemInternal(ViewPager.java:553)
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at android.support.v4.view.ViewPager.onTouchEvent(ViewPager.java:2102)
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at android.view.View.dispatchTouchEvent(View.java:7396)
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2462)
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2195)
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2468)
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2210)
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2468)
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2210)
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2468)
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2210)
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2468)
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2210)
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2468)
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2210)
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2468)
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2210)
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:2177)
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1482)
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at android.app.Activity.dispatchTouchEvent(Activity.java:2470)
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at android.support.v7.view.WindowCallbackWrapper.dispatchTouchEvent(WindowCallbackWrapper.java:60)
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at android.support.v7.view.WindowCallbackWrapper.dispatchTouchEvent(WindowCallbackWrapper.java:60)
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:2125)
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at android.view.View.dispatchPointerEvent(View.java:7581)
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at android.view.ViewRootImpl.deliverPointerEvent(ViewRootImpl.java:3571)
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:3503)
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:4614)
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:4592)
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(ViewRootImpl.java:4696)
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at android.view.InputEventReceiver.dispatchInputEvent(InputEventReceiver.java:171)
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at android.os.MessageQueue.nativePollOnce(Native Method)
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at android.os.MessageQueue.next(MessageQueue.java:125)
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at android.os.Looper.loop(Looper.java:138)
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at android.app.ActivityThread.main(ActivityThread.java:4947)
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at java.lang.reflect.Method.invokeNative(Native Method)
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at java.lang.reflect.Method.invoke(Method.java:511)
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1038)
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:805)
12-04 11:32:12.402 11884-11884/com.sample.app.mysampleapp E/MessageQueue-JNI: at dalvik.system.NativeStart.main(Native Method)
12-04 11:32:12.412 11884-11884/com.sample.app.mysampleapp D/AndroidRuntime: Shutting down VM
12-04 11:32:12.412 11884-11884/com.sample.app.mysampleapp W/dalvikvm: threadid=1: thread exiting with uncaught exception (group=0x4131e2a0)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: FATAL EXCEPTION: main
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: java.lang.NullPointerException
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at com.sample.app.mysampleapp.MainActivity.onTabUnselected(MainActivity.java:53)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at android.support.design.widget.TabLayout.selectTab(TabLayout.java:867)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at android.support.design.widget.TabLayout$TabLayoutOnPageChangeListener.onPageSelected(TabLayout.java:1759)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at android.support.v4.view.ViewPager.dispatchOnPageSelected(ViewPager.java:1794)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at android.support.v4.view.ViewPager.scrollToItem(ViewPager.java:569)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at android.support.v4.view.ViewPager.setCurrentItemInternal(ViewPager.java:553)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at android.support.v4.view.ViewPager.onTouchEvent(ViewPager.java:2102)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at android.view.View.dispatchTouchEvent(View.java:7396)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2462)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2195)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2468)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2210)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2468)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2210)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2468)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2210)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2468)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2210)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2468)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2210)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2468)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2210)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:2177)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1482)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at android.app.Activity.dispatchTouchEvent(Activity.java:2470)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at android.support.v7.view.WindowCallbackWrapper.dispatchTouchEvent(WindowCallbackWrapper.java:60)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at android.support.v7.view.WindowCallbackWrapper.dispatchTouchEvent(WindowCallbackWrapper.java:60)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:2125)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at android.view.View.dispatchPointerEvent(View.java:7581)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at android.view.ViewRootImpl.deliverPointerEvent(ViewRootImpl.java:3571)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:3503)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:4614)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:4592)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(ViewRootImpl.java:4696)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at android.view.InputEventReceiver.dispatchInputEvent(InputEventReceiver.java:171)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at android.os.MessageQueue.nativePollOnce(Native Method)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at android.os.MessageQueue.next(MessageQueue.java:125)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at android.os.Looper.loop(Looper.java:138)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at android.app.ActivityThread.main(ActivityThread.java:4947)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at java.lang.reflect.Method.invokeNative(Native Method)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at java.lang.reflect.Method.invoke(Method.java:511)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1038)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:805)
12-04 11:32:12.502 11884-11884/com.sample.app.mysampleapp E/AndroidRuntime: at dalvik.system.NativeStart.main(Native Method)
Someone can help me here? Thank you very much.
有人可以在这里帮助我吗？非常感谢你。
回答by cziemba
Okay I think I understand now, you are using the method getIcon()but you never actually set an icon via setIcon()so you are returning nullon getIcon(). You are instead using the getPageTitle()to display the icon so the tab has no idea there even is an icon.
好吧，我想我现在明白了，你所使用的方法getIcon()，但你从来没有真正通过设置一个图标setIcon()，这样你就回来null的getIcon()。您改为使用getPageTitle()来显示图标，因此选项卡甚至不知道有图标。
What I would recommend doing is modify getPageTitle()to always return nulland then create a tab setup method setupTabs()in your main activity class which should look something like:
我建议做的是修改getPageTitle()为始终返回null，然后setupTabs()在您的主活动类中创建一个选项卡设置方法，该方法应如下所示：
private void setupTabs() {
mTabLayout.getTabAt(0).setIcon(mTabIcons[0]);
mTabLayout.getTabAt(1).setIcon(mTabIcons[1]);
mTabLayout.getTabAt(2).setIcon(mTabIcons[2]);
mTabLayout.getTabAt(2).setIcon(mTabIcons[3]);
}
Also move your imageResIdarray from the adapter out to the activity:
还将您的imageResId阵列从适配器移出到活动：
private int[] mTabIcons = {
R.drawable.ic_zero
R.drawable.ic_one,
R.drawable.ic_two,
R.drawable.ic_three
};
You should also change your setOnTabSelectedListenerto use TabLayout.ViewPagerOnTabSelectedListenerso that keeping the tabs in sync is handled for you:
您还应该更改您setOnTabSelectedListener的使用，TabLayout.ViewPagerOnTabSelectedListener以便为您处理保持选项卡同步：
tabLayout.setOnTabSelectedListener(new TabLayout.ViewPagerOnTabSelectedListener(mViewPager) {
@Override
public void onTabSelected(TabLayout.Tab tab) {
super.onTabSelected(tab);
tab.getIcon().setAlpha(255);
}
@Override
public void onTabUnselected(TabLayout.Tab tab) {
super.onTabUnselected(tab);
tab.getIcon().setAlpha(127);
}
});
Then you can call setupTabs()in your onCreate():
然后你可以调用setupTabs()你的onCreate()：
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());
// Set up the ViewPager with the sections adapter.
mViewPager = (ViewPager) findViewById(R.id.pager);
mViewPager.setAdapter(mSectionsPagerAdapter);
// TabLayout
TabLayout tabLayout = (TabLayout) findViewById(R.id.tab_layout);
tabLayout.setupWithViewPager(mViewPager);
// Set up our tab icons
setupTabs();
//This is what i'm trying to add
mViewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
tabLayout.setOnTabSelectedListener(new TabLayout.ViewPagerOnTabSelectedListener(mViewPager) {
@Override
public void onTabSelected(TabLayout.Tab tab) {
super.onTabSelected(tab);
tab.getIcon().setAlpha(255);
}
@Override
public void onTabUnselected(TabLayout.Tab tab) {
super.onTabUnselected(tab);
tab.getIcon().setAlpha(127);
}
});
}
