android - 无法在Android Studio上解析符号'mapView'

Question

经过无数次尝试，我找不到解决方法。
Android不会在以下位置解析符号“ mapView”：

  mMapView = (MapView) v.findViewById(R.id.mapView);

我正在尝试做的是让Google Maps在模拟器上工作。
我知道这段代码可以在另一台PC上运行，所以我在这里猜测还有其他问题。（系统问题或Google Maps API问题）

这是代码。
有人可以帮忙吗？谢谢..

    package com.example.matant.gpsportclient.Controllers;
    import android.app.Fragment;
    import android.os.Bundle;
    import android.view.LayoutInflater;
    import android.view.View;
    import android.view.ViewGroup;

import com.example.matant.gpsportclient.AsyncResponse;
import com.example.matant.gpsportclient.R;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.MapView;
import com.google.android.gms.maps.MapsInitializer;
import com.google.android.gms.maps.model.BitmapDescriptorFactory;
import com.google.android.gms.maps.model.CameraPosition;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;

/**
 * Created by matant on 8/24/2015.
 */
public class GoogleMapFragmentController extends Fragment implements AsyncResponse {
    MapView mMapView;
    private GoogleMap googleMap;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // inflat and return the layout
        View v = inflater.inflate(R.layout.fragment_google_map_fragment_controller, container,
                false);
        mMapView = (MapView) v.findViewById(R.id.mapView);
        mMapView.onCreate(savedInstanceState);

        mMapView.onResume();//    display map immediately

        try {
            MapsInitializer.initialize(getActivity().getApplicationContext());
        } catch (Exception e) {
            e.printStackTrace();
        }

        googleMap = mMapView.getMap();
        // latitude and longitude
        double latitude = 17.385044;
        double longitude = 78.486671;

        // create marker
        MarkerOptions marker = new MarkerOptions().position(
                new LatLng(latitude, longitude)).title("Hello Maps");

        // Changing marker icon
        marker.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_ROSE));

        // adding marker
        googleMap.addMarker(marker);
        CameraPosition cameraPosition = new CameraPosition.Builder()
                .target(new LatLng(17.385044, 78.486671)).zoom(12).build();
        googleMap.animateCamera(CameraUpdateFactory
                .newCameraPosition(cameraPosition));
        googleMap.getUiSettings().setZoomControlsEnabled(true);

        // Perform any camera updates here
        return v;
    }

    @Override
    public void onResume() {
        super.onResume();
        mMapView.onResume();
    }

    @Override
    public void onPause() {
        super.onPause();
        mMapView.onPause();
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        mMapView.onDestroy();
    }

    @Override
    public void onLowMemory() {
        super.onLowMemory();
        mMapView.onLowMemory();
    }

    @Override
    public void handleResponse(String resStr) {

    }

    @Override
    public void sendDataToDBController() {

    }

    @Override
    public void preProcess() {

    }
}

表现：

    <?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.matant.gpsportclient"
    android:versionCode="1"
    android:versionName="1.0" >


    <uses-feature
        android:glEsVersion="0x00020000"
        android:required="true" />

    <uses-sdk
        android:minSdkVersion="17"
        android:targetSdkVersion="17" />

    <permission
        android:name="com.example.matant.gpsportclient.permission.MAPS_RECEIVE"
        android:protectionLevel="signature" />

    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.MANAGE_DOCUMENTS" />
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="com.google.android.providers.gsf.permission.READ_GSERVICES" />

    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
    <uses-permission android:name="com.example.matant.gpsportclient.permission.MAPS_RECEIVE" />

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".SplashScreen"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity
            android:name=".Controllers.ForgotPassword"
            android:label="@string/app_name" >
        </activity>
        <activity
            android:name=".Controllers.Login"
            android:label="@string/title_activity_login" >
        </activity>
        <activity
            android:name=".Controllers.SignUp"
            android:label="@string/title_activity_sign_up" >
        </activity>
        <activity
            android:name=".MainScreen"
            android:label="@string/title_activity_main_screen" >
        </activity>

        <meta-data
            android:name="com.google.android.gms.version"
            android:value="@integer/google_play_services_version" />
        <meta-data
            android:name="com.google.android.maps.v2.API_KEY"
            android:value="@string/google_maps_key" />
    </application>

</manifest>

build.gradle：

  apply plugin: 'com.android.application'

android {
    compileSdkVersion 21
    buildToolsVersion "23.0.0 "
    defaultConfig {
        applicationId "com.example.matant.gpsportclient"
        minSdkVersion 23
        targetSdkVersion 22
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
    productFlavors {
    }
}

dependencies {
    compile files('C:/Users/Adi/AndroidStudioProjects/GPSportClient/libs/additionnal.jar')
    compile files('C:/Users/Adi/AndroidStudioProjects/GPSportClient/libs/mail.jar')
    compile files('C:/Users/Adi/AndroidStudioProjects/GPSportClient/libs/activation.jar')
    compile fileTree(include: ['*.jar'], dir: 'libs')
    compile 'com.android.support:appcompat-v7:22.2.1'
    compile 'com.google.android.gms:play-services-maps:7.8.0'
}

布局：

<RelativeLayout 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=".MainActivity" >

    <fragment
        android:id="@+id/map"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        class="com.google.android.gms.maps.MapFragment" />

</RelativeLayout>

Answer 1

更换

 mMapView = (MapView) v.findViewById(R.id.mapView);

与

 mMapView = (MapView) v.findViewById(R.id.map);

因为片段的ID为 map。请参阅xml

<fragment
        android:id="@+id/map"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        class="com.google.android.gms.maps.MapFragment" />