应用程序不会进入静音模式，可能的音频管理器错误？

Question

在这里，当我到达特定位置时，我正试图将手机更改为静音模式。

这是一个大学项目，在这里，我试图在进入大学校园时将设备置于静音模式。

这是我的MainActivity文件。

import android.Manifest;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.location.Location;
import android.location.LocationManager;
import android.provider.Settings;
import android.support.v4.app.ActivityCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
import android.media.AudioManager;


public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    private static final int REQUEST_LOCATION = 1;
    Button button;
    TextView textView;
    LocationManager locationManager;
    public double lattitude,longitude;

    public AudioManager am;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        am = (AudioManager)getSystemService(Context.AUDIO_SERVICE);

        ActivityCompat.requestPermissions(this, new String[]{android.Manifest.permission.ACCESS_FINE_LOCATION}, REQUEST_LOCATION);

        textView = (TextView)findViewById(R.id.text_location);
        button = (Button)findViewById(R.id.button_location);

        button.setOnClickListener(this);

        if(lattitude == 21.92000007629394 || longitude == 82.77999877929686){
           am.setRingerMode(AudioManager.RINGER_MODE_SILENT);

        }
        else if(lattitude == 18.587765599999997 || longitude == 73.7407158){
            am.setRingerMode(AudioManager.RINGER_MODE_SILENT);
        }

    }

    @Override
    public void onClick(View view) {
        locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
        if (!locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER)) {
            buildAlertMessageNoGps();

        } else if (locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER)) {
            getLocation();


        }
    }

    private void getLocation() {
        if (ActivityCompat.checkSelfPermission(MainActivity.this, Manifest.permission.ACCESS_FINE_LOCATION)
                != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission
                (MainActivity.this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {

            ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, REQUEST_LOCATION);

        } else {
            Location location = locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);

            Location location1 = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);

            Location location2 = locationManager.getLastKnownLocation(LocationManager. PASSIVE_PROVIDER);

            if (location != null) {
                double latti = location.getLatitude();
                double longi = location.getLongitude();
                lattitude = latti;
                longitude = longi;

                textView.setText("Your current location is"+ "\n" + "Lattitude = " + lattitude
                        + "\n" + "Longitude = " + longitude);




            } else  if (location1 != null) {
                double latti = location1.getLatitude();
                double longi = location1.getLongitude();
                lattitude = latti;
                longitude = longi;

                textView.setText("Your current location is"+ "\n" + "Lattitude = " + lattitude
                        + "\n" + "Longitude = " + longitude);




            } else  if (location2 != null) {
                double latti = location2.getLatitude();
                double longi = location2.getLongitude();
                lattitude = latti;
                longitude = longi;

                textView.setText("Your current location is"+ "\n" + "Lattitude = " + lattitude
                        + "\n" + "Longitude = " + longitude);



            }else{

                Toast.makeText(this,"Unable to Trace your location",Toast.LENGTH_SHORT).show();

            }
        }
    }

    protected void buildAlertMessageNoGps() {

        final AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setMessage("Please Turn ON your GPS Connection")
                .setCancelable(false)
                .setPositiveButton("Yes", new DialogInterface.OnClickListener() {
                    public void onClick(final DialogInterface dialog, final int id) {
                        startActivity(new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS));
                    }
                })
                .setNegativeButton("No", new DialogInterface.OnClickListener() {
                    public void onClick(final DialogInterface dialog, final int id) {
                        dialog.cancel();
                    }
                });
        final AlertDialog alert = builder.create();
        alert.show();
    }

}

我尝试将代码设置为在不同的地方将手机更改为静音模式，例如在打印纬度和经度之后以及在调用getLocation（）之前，但是其中任何一个都会崩溃应用程序。

这是我的清单文件

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.idks.locationsilent">



    <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">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

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

    <uses-permission android:name="android.permission.INTERNET"/>
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
    <uses-permission android:name="android.permission.WRITE_SETTINGS"/>
    <uses-permission android:name="android.permission.WRITE_SECURE_SETTINGS"/>
</manifest>

Answer 1

在最近的API中，我们需要访问应用程序来更改手机配置文件。

我只需要添加这个片段。

 NotificationManager notificationManager =
                (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M
                && !notificationManager.isNotificationPolicyAccessGranted()) {

            Intent intent = new Intent(
                    android.provider.Settings
                            .ACTION_NOTIFICATION_POLICY_ACCESS_SETTINGS);

            startActivity(intent);
        }