我试图在Android Studio中学习编码，但我在活动中遇到了问题。
我有一个谷歌地图代码，我想添加到导航抽屉中，但我不能，因为错误总是说MapsActivity不能转换为androidx.fragment.app.fragment
这是我的MapActivity.Java
package ***.***.***.ui.map;
import androidx.fragment.app.FragmentActivity;
import android.annotation.SuppressLint;
import android.content.Context;
import android.location.Address;
import android.location.Geocoder;
import android.location.LocationManager;
import android.os.Bundle;
import android.view.WindowManager;
import android.widget.TextView;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
import java.io.IOException;
import java.util.List;
public class MapsActivity extends FragmentActivity implements OnMapReadyCallback {
private Object LocationServices;
GoogleMap mMap;
private GoogleMap.OnCameraIdleListener onCameraIdleListener;
private TextView resutText;
@Override
public void onResume() {
super.onResume();
// 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);
resutText = (TextView) findViewById(***.***.***.R.id.dragg_result);
configureCameraIdle();
}
@Override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
mMap.setOnCameraIdleListener(onCameraIdleListener);
googleMap.setMapType(GoogleMap.MAP_TYPE_NORMAL);
LocationManager locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
String locationProvider = LocationManager.NETWORK_PROVIDER;
@SuppressLint("MissingPermission") android.location.Location lastKnownLocation = locationManager.getLastKnownLocation(locationProvider);
double userLat = lastKnownLocation.getLatitude();
double userLong = lastKnownLocation.getLongitude();
LatLng user = new LatLng(userLat, userLong);
googleMap.animateCamera(CameraUpdateFactory.newLatLngZoom(new LatLng(userLat, userLong), 16.0f));
}
private void configureCameraIdle() {
onCameraIdleListener = new GoogleMap.OnCameraIdleListener() {
@Override
public void onCameraIdle() {
LatLng latLng = mMap.getCameraPosition().target;
Geocoder geocoder = new Geocoder(MapsActivity.this);
try {
List<Address> addressList = geocoder.getFromLocation(latLng.latitude, latLng.longitude, 1);
if (addressList != null && addressList.size() > 0) {
String locality = addressList.get(0).getAddressLine(0);
String country = addressList.get(0).getCountryName();
if (!locality.isEmpty() && !country.isEmpty())
resutText.setText(locality + " " + country);
}
} catch (IOException e) {
e.printStackTrace();
}
}
};
}
protected void setStatusBarTranslucent(boolean makeTranslucent) {
if (makeTranslucent) {
getWindow().addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
} else {
getWindow().clearFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
}
}
}
和activity_maps.xml
<?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"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<fragment
android:id="@+id/map"
android:name="com.google.android.gms.maps.SupportMapFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MapsActivity" />
<ImageView
android:id="@+id/imageView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:layout_alignParentEnd="true"
android:layout_alignParentBottom="true"
android:layout_marginStart="172dp"
android:layout_marginTop="310dp"
android:layout_marginEnd="172dp"
android:layout_marginBottom="356dp"
android:adjustViewBounds="true"
android:maxWidth="65dp"
android:maxHeight="65dp"
android:src="@drawable/car_pin" />
<!-- Implementation of find my location button -->
<TextView
android:id="@+id/dragg_result"
android:layout_width="260dp"
android:layout_height="84dp"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:layout_alignParentEnd="true"
android:layout_alignParentBottom="true"
android:layout_marginStart="75dp"
android:layout_marginTop="74dp"
android:layout_marginEnd="75dp"
android:layout_marginBottom="572dp"
android:text="TextView" />
<fragment
android:id="@+id/nav_host_fragment"
android:name="androidx.navigation.fragment.NavHostFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:defaultNavHost="true"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:navGraph="@navigation/mobile_navigation" />
</RelativeLayout>
还有MainActivity.java
package ***.***.***;
import android.os.Bundle;
import android.view.View;
import android.view.Menu;
import com.google.android.material.floatingactionbutton.FloatingActionButton;
import com.google.android.material.snackbar.Snackbar;
import com.google.android.material.navigation.NavigationView;
import androidx.navigation.NavController;
import androidx.navigation.Navigation;
import androidx.navigation.ui.AppBarConfiguration;
import androidx.navigation.ui.NavigationUI;
import androidx.drawerlayout.widget.DrawerLayout;
import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;
public class MainActivity extends AppCompatActivity {
private AppBarConfiguration mAppBarConfiguration;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
FloatingActionButton fab = findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
}
});
DrawerLayout drawer = findViewById(R.id.drawer_layout);
NavigationView navigationView = findViewById(R.id.nav_view);
// Passing each menu ID as a set of Ids because each
// menu should be considered as top level destinations.
mAppBarConfiguration = new AppBarConfiguration.Builder(
R.id.nav_home, R.id.nav_gallery, R.id.nav_slideshow)
.setDrawerLayout(drawer)
.build();
NavController navController = Navigation.findNavController(this, R.id.nav_host_fragment);
NavigationUI.setupActionBarWithNavController(this, navController, mAppBarConfiguration);
NavigationUI.setupWithNavController(navigationView, navController);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public boolean onSupportNavigateUp() {
NavController navController = Navigation.findNavController(this, R.id.nav_host_fragment);
return NavigationUI.navigateUp(navController, mAppBarConfiguration)
|| super.onSupportNavigateUp();
}
}
我能做些什么让它在不重做所有代码的情况下工作，提前谢谢。
我不太确定，但我认为您必须将<framgent>放入xml文件中的<FramgeLayout>中，如下所示：
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<fragment
android:id="@+id/mapfragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
class="com.google.android.gms.maps.MapFragment"/>
<!-- other components -->
<fragment
android:id="@+id/nav_host_fragment"
android:name="androidx.navigation.fragment.NavHostFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:defaultNavHost="true"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:navGraph="@navigation/mobile_navigation" />
</FrameLayout>
你们的进口可能是错的。如果您在java类android.support.v4.app.FragmentActivity而不是androidx.fragment.app.FragmentActivity中导入它，它会起作用吗？我认为错误是在进口比