正如标题所说,我的应用程序中有多个使用 ViewPager 创建的选项卡。我有一个 Android 浮动操作按钮,我只想在两个选项卡上显示。我[大部分]都在工作。
当我启动我的应用程序时,将显示选项卡 #1。 当我单击选项卡 #1 上的 FAB 时,没有任何反应。如果我滑动到选项卡 #2 并单击其 FAB,则可以完美运行。但是,如果我滑动回选项卡#1,那么FAB也可以正常工作。选项卡 #1 的 FAB 仅在我切换到新选项卡然后返回选项卡 #1 后才有效。
那么,如何在首次启动时修复默认选项卡(选项卡 #1(上的 FAB?
谢谢!
这是我所拥有的:
主活动.java
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final FloatingActionButton fab = (FloatingActionButton)findViewById(R.id.fab);
TabLayout tabLayout = (TabLayout) findViewById(R.id.tab_layout);
tabLayout.addTab(tabLayout.newTab().setText(Constants.TAB_01));
tabLayout.addTab(tabLayout.newTab().setText(Constants.TAB_02));
tabLayout.addTab(tabLayout.newTab().setText(Constants.TAB_03));
tabLayout.addTab(tabLayout.newTab().setText(Constants.TAB_04));
tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);
viewPager = (ViewPager) findViewById(R.id.pager);
pagerAdapter = new PagerAdapter (getSupportFragmentManager(), tabLayout.getTabCount());
viewPager.setAdapter(pagerAdapter);
viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
tabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
@Override
public void onTabSelected(TabLayout.Tab tab) {
viewPager.setCurrentItem(tab.getPosition());
if (tab.getPosition() == Constants.TAB_INDEX_TAB_01) {
if (fab != null) {
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent activity01Intent = new Intent(getApplicationContext(), Activity01.class);
if (activity01Intent != null) {
try {
startActivity(activity01Intent);
} catch (ActivityNotFoundException anfe) {
Toast.makeText(getApplicationContext(), "ERROR ...", Toast.LENGTH_SHORT).show();
}
}
}
});
}
fab.show();
} else if(tab.getPosition() == Constants.TAB_INDEX_TAB_02){
if(fab != null) {
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent activity02Intent = new Intent(getApplicationContext(), Activity02.class);
if (activity02Intent != null) {
try {
startActivity(activity02Intent);
} catch (ActivityNotFoundException anfe) {
Toast.makeText(getApplicationContext(), "ERROR ...", Toast.LENGTH_SHORT).show();
}
}
}
});
}
fab.show();
} else {
fab.hide();
}
}
@Override
public void onTabUnselected(TabLayout.Tab tab) { }
@Override
public void onTabReselected(TabLayout.Tab tab) { }
});
}
}
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true">
<include layout="@layout/content_main" />
<android.support.design.widget.FloatingActionButton
android:id="@+id/fab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="bottom|end"
android:layout_margin="@dimen/fab_margin"
app:backgroundTint="@color/DIMGRAY"
android:src="@android:drawable/ic_input_add" />
</android.support.design.widget.CoordinatorLayout>
只需在Oncreate中定义它,也希望它有效。
if (fab != null) {
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent activity01Intent = new Intent(getApplicationContext(), Activity01.class);
if (activity01Intent != null) {
try {
startActivity(activity01Intent);
} catch (ActivityNotFoundException anfe) {
Toast.makeText(getApplicationContext(), "ERROR ...", Toast.LENGTH_SHORT).show();
}
}
}
});
}
fab.show();