java - fragment 未在家庭 Activity 中显示

Question

我在 map Activity 上添加了抽屉导航。现在，我尝试在我的家庭 Activity 中添加一个 fragment ，但 fragment 未在 Activity 中显示，但 fragment 类中的代码正在运行。我的 FrameLayout 是否隐藏在 map fragment 后面？

我对 Fragments 很陌生。请帮助我。

首页布局

       <?xml version="1.0" encoding="utf-8"?>

    <androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"

xmlns:map="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/constrain_layout"
android:orientation="vertical">


    <FrameLayout
        android:id="@+id/fragment_container"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        map:layout_constraintBottom_toBottomOf="parent"
        map:layout_constraintEnd_toEndOf="parent"
        map:layout_constraintStart_toStartOf="parent"
        map:layout_constraintTop_toTopOf="parent" />

    <fragment
        android:id="@+id/map"
        android:name="com.google.android.gms.maps.SupportMapFragment"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        map:layout_constraintBottom_toBottomOf="parent"
        map:layout_constraintEnd_toEndOf="parent"
        map:layout_constraintHorizontal_bias="0.0"
        map:layout_constraintStart_toStartOf="parent"
        map:layout_constraintTop_toTopOf="parent"
        map:layout_constraintVertical_bias="0.0"
        tools:context=".HomeActivity" />

</androidx.constraintlayout.widget.ConstraintLayout>

fragment 类

public class RideHistory extends Fragment {

@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {

    Toast.makeText(getActivity(), "Ride History", Toast.LENGTH_SHORT).show();
    View view = inflater.inflate(R.layout.fragment_ride_history,container,false);
    return view;
}

}

xml fragment

    <?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Fragments.RideHistory">

    <!-- TODO: Update blank fragment layout -->
    <TextView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:text="Ride History" />

</FrameLayout>

Answer 1

更改布局约束，以便小部件框架布局和 map fragment 不会相互重叠。例如:

<FrameLayout
    android:id="@+id/fragment_container"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    map:layout_constraintBottom_toTopOf="@+id/map"
    map:layout_constraintEnd_toEndOf="parent"
    map:layout_constraintStart_toStartOf="parent"
    map:layout_constraintTop_toTopOf="parent" />
<fragment
    android:id="@+id/map"
    android:name="com.google.android.gms.maps.SupportMapFragment"
    android:layout_width="434dp"
    android:layout_height="297dp"
    map:layout_constraintBottom_toBottomOf="parent"
    map:layout_constraintEnd_toEndOf="parent"
    map:layout_constraintHorizontal_bias="0.0"
    map:layout_constraintStart_toStartOf="parent"
    tools:context=".HomeActivity" />