不可轉換的類型； 無法將“android.support.v4.app.Fragment”轉換為“com.google.android.gms.maps.SupportMapFragment”

Question

我已經創建了一個谷歌地圖的活動，那就是當錯誤彈出時，在活動的構建完成后就會出現錯誤。 錯誤是：

 Inconvertible types; cannot cast 'android.support.v4.app.Fragment' to 'com.google.android.gms.maps.SupportMapFragment'

在行中（在 MapsActivity 中）：

SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager() .findFragmentById(R.id.map);

而且我還在資源中輸入了API密鑰！！

進口：

import android.support.v4.app.FragmentActivity;

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 com.google.android.gms.maps.model.MarkerOptions;

顯現：

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    package="com.purabjain.memorableplaces">

    <!--
         The ACCESS_COARSE/FINE_LOCATION permissions are not required to use
         Google Maps Android API v2, but you must specify either coarse or fine
         location permissions for the 'MyLocation' functionality.
    -->
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme"
        tools:replace="android:appComponentFactory"
        android:appComponentFactory="whateverString">

        <!--
             The API key for Google Maps-based APIs is defined as a string resource.
             (See the file "res/values/google_maps_api.xml").
             Note that the API key is linked to the encryption key used to sign the APK.
             You need a different API key for each encryption key, including the release key that is used to
             sign the APK for publishing.
             You can define the keys for the debug and release targets in src/debug/ and src/release/.
        -->
        <meta-data
            android:name="com.google.android.geo.API_KEY"
            android:value="@string/google_maps_key" />

        <activity
            android:name=".MapsActivity"
            android:label="@string/title_activity_maps"></activity>
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

構建.gradle：

android {
    compileSdkVersion 28
    defaultConfig {
        applicationId "com.purabjain.memorableplaces"
        minSdkVersion 21
        targetSdkVersion 28
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support:appcompat-v7:28.0.0'
    implementation 'com.android.support.constraint:constraint-layout:1.1.3'
    implementation 'com.google.android.gms:play-services-maps:17.0.0'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.2'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
}

地圖活動：

import android.os.Bundle;
import android.support.v4.app.FragmentActivity;

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 com.google.android.gms.maps.model.MarkerOptions;

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);
    }


    /**
     * Manipulates the map once available.
     * This callback is triggered when the map is ready to be used.
     * This is where we can add markers or lines, add listeners or move the camera. In this case,
     * we just add a marker near Sydney, Australia.
     * If Google Play services is not installed on the device, the user will be prompted to install
     * it inside the SupportMapFragment. This method will only be triggered once the user has
     * installed Google Play services and returned to the app.
     */
    @Override
    public void onMapReady(GoogleMap googleMap) {
       /* mMap = googleMap;

        // Add a marker in Sydney and move the camera
        LatLng sydney = new LatLng(-34, 151);
        mMap.addMarker(new MarkerOptions().position(sydney).title("Marker in Sydney"));
        mMap.moveCamera(CameraUpdateFactory.newLatLng(sydney));*/
    }
}

api.xml：

    <!--
    TODO: Before you run your application, you need a Google Maps API key.

    To get one, follow this link, follow the directions and press "Create" at the end:

    https://console.developers.google.com/flows/enableapi?apiid=maps_android_backend&keyType=CLIENT_SIDE_ANDROID&r=E6:56:90:82:E2:58:42:66:59:4C:5A:F2:E5:9B:64:06:EC:1E:05:49%3Bcom.purabjain.memorableplaces

    You can also add your credentials to an existing key, using these values:

    Package name:
    E6:56:90:82:E2:58:42:66:59:4C:5A:F2:E5:9B:64:06:EC:1E:05:49

    SHA-1 certificate fingerprint:
    E6:56:90:82:E2:58:42:66:59:4C:5A:F2:E5:9B:64:06:EC:1E:05:49

    Alternatively, follow the directions here:
    https://developers.google.com/maps/documentation/android/start#get-key

    Once you have your key (it starts with "AIza"), replace the "google_maps_key"
    string in this file.
    -->
    <string name="google_maps_key" templateMergeStrategy="preserve" translatable="false">AIzaSyDaCq_mx5h741VnM-4tNkNmQiT70yf7ykw</string>
</resources>

Answer 1

我也為這個問題而苦苦掙扎，但事實證明，新版的Google地圖使用的AndroidX版本為17.0.0。 所以你應該使用16.1.0

所以改變這個：

implementation 'com.google.android.gms:play-services-maps:17.0.0'

對此：

implementation 'com.google.android.gms:play-services-maps:16.1.0'

另外，請確保您沒有使用任何使用AndroidX的應用：在我的情況下，我使用了這會造成麻煩：

implementation 'com.google.android.gms:play-services-location:17.0.0'

所以我也這么做了

implementation 'com.google.android.gms:play-services-location:16.0.0'

這是版本列表； https://mvnrepository.com/artifact/com.google.android.gms/play-services-maps

正確版本的Google Play服務： https ： //developers.google.com/android/guides/releases

Answer 2

將它們添加到build.gradle（Module：app）文件中：

androidTestImplementation 'androidx.test:runner:1.2.0'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'

Answer 3

我在'androidx.fragment.app.fragment' 到 'com.google.android.gms.maps.supportmapfragment'有類似的問題，解決方案是更改谷歌地圖的版本。

從：

implementation 'com.google.android.gms:play-services-maps:16.0.0'

到：

implementation 'com.google.android.gms:play-services-maps:17.0.0'