片段重叠的标签布局

Question

当我启动我的应用程序时，一切都很好，除了片段重叠了我的标签布局。切换选项卡很好，但是片段布局似乎覆盖了整个屏幕，而不是处于布局之下。有人知道解决方案吗？截图：https://imgur.com/a/odeKD0W希望我没有忘记添加一些内容，如果有的话，问我。谢谢。

ActivityMain

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        TabLayout tabLayout = findViewById(R.id.tabBar);
        TabItem tabItem1 = findViewById(R.id.tab1);
        TabItem tabItem2 = findViewById(R.id.tab2);
        TabItem tabItem3 = findViewById(R.id.tab3);
        final ViewPager viewPager = findViewById(R.id.viewPager);

        PagerAdapter pagerAdapter = new PagerAdapter(getSupportFragmentManager(), tabLayout.getTabCount());

        viewPager.setAdapter(pagerAdapter);

        tabLayout.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
            @Override
            public void onTabSelected(TabLayout.Tab tab) {
                viewPager.setCurrentItem(tab.getPosition());
            }

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

            }

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

            }
        });
        viewPager.addOnPageChangeListener(new TabLayout
                .TabLayoutOnPageChangeListener(tabLayout));
    }
}

PagerAdapter类

public class PagerAdapter extends FragmentPagerAdapter {

    private int numOfTabs;
    public PagerAdapter (FragmentManager fm, int numOfTabs) {
        super (fm);
        this.numOfTabs = numOfTabs;
    }
    @NonNull
    @Override
    public Fragment getItem(int position) {
        switch (position){
            case 0:
                return new FragmentTab1();
            case 1:
                return new FragmentTab2();
            case 2:
                return new FragmentTab3();
            default:
                return null;
        }

    }

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

Activity_Main xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <com.google.android.material.tabs.TabLayout
        android:id="@+id/tabBar"
        android:layout_width="409dp"
        android:layout_height="0dp"
        android:layout_marginStart="1dp"
        android:layout_marginEnd="1dp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">

        <com.google.android.material.tabs.TabItem
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/tab1"
            android:text="Tab 1" />

        <com.google.android.material.tabs.TabItem
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/tab2"
            android:text="Tab 2" />

        <com.google.android.material.tabs.TabItem
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/tab3"
            android:text="Tab 3" />
    </com.google.android.material.tabs.TabLayout>

    <androidx.viewpager.widget.ViewPager
        android:id="@+id/viewPager"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="@id/tabBar" />
  </androidx.constraintlayout.widget.ConstraintLayout>

Answer 1

您正在使用

app:layout_constraintTop_toTopOf="@id/tabBar"

代替

app:layout_constraintTop_toBottomOf="@id/tabBar"

首先将片段的顶部与TabLayout的顶部对齐，它们将重叠。片段的顶部应该限制在选项卡的底部。