在地图片段顶部添加按钮

Question

我正在尝试在我的 Google 地图片段顶部实现一个按钮，但我看不到它。

这是代码（我也尝试将按钮放在片段之外）：

<FrameLayout 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:background="@drawable/side_nav_bar"
android:gravity="bottom"
android:orientation="vertical"
android:theme="@style/ThemeOverlay.AppCompat.Dark">

<fragment 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:id="@+id/map"
    android:name="com.google.android.gms.maps.SupportMapFragment"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.user.car.MapsActivity">


    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="right|top"
        android:text="Demo Button"
        android:padding="10dp"
        android:layout_marginTop="20dp"
        android:paddingRight="10dp"/>

</fragment>

另外，这部分用到的java文件如下：

public class MapsActivity extends FragmentActivity implements OnMapReadyCallback {

private GoogleMap mMap;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_maps);
    // Obtain the SupportMapFragment and get notified when the map is ready to be used.
    SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
            .findFragmentById(R.id.map);
    mapFragment.getMapAsync(this);
}

编辑：这是启动地图的代码，可能会导致问题：

    //this function initializes the map presentation
private void initMap() {
    SupportMapFragment map_fragment = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.main_map);
    map_fragment.getMapAsync(new OnMapReadyCallback() {
        @Override
        public void onMapReady(GoogleMap googleMap) {
            user_map = googleMap;
            Toast.makeText(getApplicationContext(), "Map is ready!", Toast.LENGTH_SHORT).show();

            if (mLocationPermissionGranted) {
                getDeviceLocation();

                if (ActivityCompat.checkSelfPermission(getApplicationContext(), Manifest.permission.ACCESS_FINE_LOCATION)
                        != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(getApplicationContext()
                        , Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
                    return;
                }
                user_map.setMyLocationEnabled(true);

                user_map.getUiSettings().setMyLocationButtonEnabled(true);

            }
        }
    });
}

这是我得到的输出（仅显示地图，没有按钮）： https://prnt.sc/iq5ic3

Answer 1

试试这个。删除了该按钮的一些属性 b'z 被隐藏。

<RelativeLayout 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:orientation="vertical"
    android:theme="@style/ThemeOverlay.AppCompat.Dark">

    <fragment
        xmlns:map="http://schemas.android.com/apk/res-auto"
        xmlns:tools="http://schemas.android.com/tools"
        android:id="@+id/map"
        android:name="com.google.android.gms.maps.SupportMapFragment"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context="com.example.user.car.MapsActivity"/>

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="20dp"
        android:padding="10dp"
        android:layout_centerVertical="true"
        android:layout_centerHorizontal="true"
        android:paddingRight="10dp"
        android:text="Demo Button" />

</RelativeLayout>

Answer 2

试试这个

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 
 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:theme="@style/ThemeOverlay.AppCompat.Dark">

<FrameLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent">

<fragment 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:id="@+id/map"
    android:name="com.google.android.gms.maps.SupportMapFragment"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.user.car.MapsActivity"></fragment>

</FrameLayout>

<Button
    android:id="@+id/button2"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true"
    android:layout_marginBottom="20dp"
    android:text="Demo Button" />

输出：

Answer 3

试试这个

<RelativeLayout 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:theme="@style/ThemeOverlay.AppCompat.Dark">

<fragment 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:id="@+id/map"
    android:name="com.google.android.gms.maps.SupportMapFragment"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    tools:context="com.example.user.car.MapsActivity"></fragment>

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignBottom="@+id/map"
    android:layout_alignParentEnd="true"
    android:layout_marginTop="20dp"
    android:padding="10dp"
    android:paddingRight="10dp"
    android:text="Demo Button" />

将按钮放在RelativeLayout 内