11

我的 /raw 文件夹中有声音，我希望我的用户能够像 RingtonePreference 一样在首选项中选择一种声音，但仅限于我的声音。

4

4 回答 4

18

这是我的 RingtonePreference 替换。列出了所有系统铃声和您的自定义铃声（在 xml 中定义，存储在 res/raw 中）：

ExtraRingtonePreference.java 

package de.almisoft.test;

import java.util.Arrays;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.TreeMap;

import de.almisoft.test.R;

import android.app.AlertDialog.Builder;
import android.content.Context;
import android.content.DialogInterface;
import android.content.res.TypedArray;
import android.database.Cursor;
import android.media.Ringtone;
import android.media.RingtoneManager;
import android.net.Uri;
import android.preference.DialogPreference;
import android.util.AttributeSet;

public class ExtraRingtonePreference extends DialogPreference {

    private Context mContext;
    private String mValue;
    private Ringtone ringtone;
    private int mRingtoneType;
    private boolean mShowSilent;
    private boolean mShowDefault;
    private CharSequence[] mExtraRingtones;
    private CharSequence[] mExtraRingtoneTitles;

    public ExtraRingtonePreference(Context context, AttributeSet attrs) {

        super(context, attrs);

        mContext = context;

        final TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.ExtraRingtonePreference, 0, 0);

        mRingtoneType = a.getInt(R.styleable.ExtraRingtonePreference_ringtoneType, RingtoneManager.TYPE_RINGTONE);
        mShowDefault = a.getBoolean(R.styleable.ExtraRingtonePreference_showDefault, true);
        mShowSilent = a.getBoolean(R.styleable.ExtraRingtonePreference_showSilent, true);
        mExtraRingtones = a.getTextArray(R.styleable.ExtraRingtonePreference_extraRingtones);
        mExtraRingtoneTitles = a.getTextArray(R.styleable.ExtraRingtonePreference_extraRingtoneTitles);

        a.recycle();
    }

    public ExtraRingtonePreference(Context context) {
        this(context, null);
    }

    public String getValue() {
        return mValue;
    }

    private Map<String, Uri> getSounds(int type) {

        RingtoneManager ringtoneManager = new RingtoneManager(mContext);
        ringtoneManager.setType(type);
        Cursor cursor = ringtoneManager.getCursor();

        Map<String, Uri> list = new TreeMap<String, Uri>();
        while (cursor.moveToNext()) {
            String notificationTitle = cursor.getString(RingtoneManager.TITLE_COLUMN_INDEX);
            Uri notificationUri =  ringtoneManager.getRingtoneUri(cursor.getPosition());

            list.put(notificationTitle, notificationUri);
        }

        return list;
    }

    private Uri uriFromRaw(String name) {
        int resId = mContext.getResources().getIdentifier(name, "raw", mContext.getPackageName());
        return Uri.parse("android.resource://" + mContext.getPackageName() + "/" + resId);
    }

    private String getExtraRingtoneTitle(CharSequence name) {
        if (mExtraRingtones != null && mExtraRingtoneTitles != null) {
            int index = Arrays.asList(mExtraRingtones).indexOf(name);
            return mExtraRingtoneTitles[index].toString(); 
        } 

        return null;
    }

    @Override
    public CharSequence getSummary() {

        String ringtoneTitle = null;

        if (mValue != null) {

            if (mValue.length() == 0)
                ringtoneTitle = mContext.getString(R.string.silent);

            if (ringtoneTitle == null && mExtraRingtones != null && mExtraRingtoneTitles != null) {

                for (int i = 0; i < mExtraRingtones.length; i++) {

                    Uri uriExtra = uriFromRaw(mExtraRingtones[i].toString());

                    if (uriExtra.equals(Uri.parse(mValue))) {
                        ringtoneTitle = mExtraRingtoneTitles[i].toString();
                        break;
                    }
                }
            }

            if (ringtoneTitle == null) {
                Ringtone ringtone = RingtoneManager.getRingtone(mContext, Uri.parse(mValue));
                String title = ringtone.getTitle(mContext);
                if (title != null && title.length() > 0)
                ringtoneTitle = title;
            }

        }

        CharSequence summary = super.getSummary();

        if (ringtoneTitle != null) { 
            if (summary != null)
                return String.format(summary.toString(), ringtoneTitle);
            else
                return ringtoneTitle;
        } else return summary;
}

    @Override
    protected void onPrepareDialogBuilder(Builder builder) {

        final Map<String, Uri> sounds = new LinkedHashMap<String, Uri>();

        if (mExtraRingtones != null) {
            for (CharSequence extraRingtone : mExtraRingtones) {
                Uri uri = uriFromRaw(extraRingtone.toString());
                String title = getExtraRingtoneTitle(extraRingtone);

                sounds.put(title, uri);
            }
        }

        if (mShowDefault) {
            Uri uriDefault = RingtoneManager.getDefaultUri(mRingtoneType);
            if (uriDefault != null) {
                Ringtone ringtoneDefault = RingtoneManager.getRingtone(mContext, uriDefault);
                if (ringtoneDefault != null) {
                    sounds.put(ringtoneDefault.getTitle(mContext), uriDefault);
                }
            }   
        }

        if (mShowSilent) 
            sounds.put(mContext.getString(R.string.silent), Uri.parse(""));


        sounds.putAll(getSounds(RingtoneManager.TYPE_NOTIFICATION));


        final String[] titleArray = sounds.keySet().toArray(new String[0]);
        final Uri[] uriArray = sounds.values().toArray(new Uri[0]);

        int index = mValue != null ? Arrays.asList(uriArray).indexOf(Uri.parse(mValue)) : -1;

        builder.setSingleChoiceItems(titleArray, index, new DialogInterface.OnClickListener() {

            public void onClick(DialogInterface dialog, int which) {

                if (ringtone != null)
                    ringtone.stop();

                String title = titleArray[which];
                Uri uri = uriArray[which];

                if (uri != null) {
                    if (uri.toString().length() > 0) {
                        ringtone = RingtoneManager.getRingtone(mContext, uri);
                        ringtone.play();
                    }
                    mValue = uri.toString();
                } else mValue = null;

            }
        });

        builder.setPositiveButton(R.string.ok, this);
        builder.setNegativeButton(R.string.cancel, this);

    }

    @Override
    protected void onDialogClosed(boolean positiveResult) {

        super.onDialogClosed(positiveResult);

        if (ringtone != null)
            ringtone.stop();

        if (positiveResult && callChangeListener(mValue)) {
            persistString(mValue);
            notifyChanged();
        }

    }

    @Override
    protected Object onGetDefaultValue(TypedArray a, int index) {
        return a.getString(index);
    }

    @Override
    protected void onSetInitialValue(boolean restoreValue, Object defaultValue) {

        if (restoreValue)
            mValue = getPersistedString("");
        else {
            if (mExtraRingtones != null && defaultValue != null && defaultValue.toString().length() > 0) {

                int index = Arrays.asList(mExtraRingtones).indexOf((CharSequence) defaultValue);
                if (index >= 0) 
                    mValue = uriFromRaw(defaultValue.toString()).toString();
                else mValue = (String) defaultValue; 

        } else mValue = (String) defaultValue; 

            persistString(mValue);
        }


    }


}

资源/值/attrs.xml

<?xml version="1.0" encoding="UTF-8"?>
<resources>
    <declare-styleable name="ExtraRingtonePreference">
        <attr name="ringtoneType">
            <!-- Ringtones. -->
            <flag name="ringtone" value="1" />
            <!-- Notification sounds. -->
            <flag name="notification" value="2" />
            <!-- Alarm sounds. -->
            <flag name="alarm" value="4" />
            <!-- All available ringtone sounds. -->
            <flag name="all" value="7" />
        </attr>
        <attr name="showSilent" format="boolean"/>
        <attr name="showDefault" format="boolean"/>
        <attr name="extraRingtones" format="reference"/>
        <attr name="extraRingtoneTitles" format="reference"/>
    </declare-styleable>

</resources>

res/values/strings.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <string name="silent">Silent</string>
    <string name="ok">OK</string>
    <string name="cancel">Cancel</string>
    <string name="ringtoneTitle">Ringtone</string>
    <string name="ringtoneSummary">Ringtone: %s</string>

    <string-array name="extraRingtones">
        <item>deichkind_sone_musik</item>
        <item>madonna_like_a_virgin</item>
    </string-array>

    <string-array name="extraRingtoneTitles">
        <item>Sone Musik</item>
        <item>Like A Virgin</item>
    </string-array>
</resources>

资源/原始

res
 ↳ raw
    ↳ deichkind_sone_musik.mp3
    ↳ madonna_like_a_virgin.mp3

res/xml/preferences.xml

<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen 
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:auto="http://schemas.android.com/apk/res-auto">

    <de.almisoft.test.ExtraRingtonePreference
        android:key="ringtone"
        android:title="@string/ringtoneTitle"
        android:summary="@string/ringtoneSummary"
        android:defaultValue="deichkind_sone_musik"
        auto:ringtoneType="notification"
        auto:showSilent="true"
        auto:showDefault="true"
        auto:extraRingtones="@array/extraRingtones"
        auto:extraRingtoneTitles="@array/extraRingtoneTitles"/>

    <!-- set android:defaultValue 
         to "deichkind_sone_musik" for your custom mp3
         to "" for silent
         to "content://settings/system/notification_sound" for system default ringtone -->

</PreferenceScreen>
于 2015-06-23T13:38:20.700 回答
3

所以最后我查看了 ListPreference 的源代码，并做了一些修改。由于我不能使用 com.android.internal.R.styleable.ListPreference 我必须在 attrs.xml 创建自己的样式：

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <declare-styleable name="ListPreference">
        <attr name="entries" format="string"></attr>
        <attr name="entryValues" format="string"></attr>
    </declare-styleable>
    <declare-styleable name="Preference">
        <attr name="summary" format="string"></attr>
    </declare-styleable>
</resources>

然后将其导入到我的preferences.xml 文件中，如下所示：

 xmlns:foo="http://schemas.android.com/apk/res/com.abe.abemoto"

并使用它：

    <com.abe.abemoto.preference.CustomSoundListPreference
        android:defaultValue="@string/pref_alert_ring_value_1"
        android:key="@string/pref_alert_sound_choice_for_notif_key"
        android:title="Sonnerie de notification"
        foo:entries="@array/pref_alert_ring_entries"
        foo:entryValues="@array/pref_alert_ring_values"
        foo:summary="Choisissez la sonnerie pour les notifications" />

在我的类 CustomSoundListPreference 中，我修改了 onPrepareDialogBu​​ilder 方法以在单击的项目上播放我的声音。

    @Override
protected void onPrepareDialogBuilder(Builder builder) {
    super.onPrepareDialogBuilder(builder);

    mMediaPlayer = new MediaPlayer();

    if (mEntries == null || mEntryValues == null) {
        throw new IllegalStateException(
                "ListPreference requires an entries array and an entryValues array.");
    }

    mClickedDialogEntryIndex = getValueIndex();
    builder.setSingleChoiceItems(mEntries, mClickedDialogEntryIndex,
            new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int which) {
                    mClickedDialogEntryIndex = which;

                    String value = mEntryValues[which].toString();

                    Resources res = getContext().getResources();
                    int resId = res.getIdentifier(value, "raw",
                            getContext().getPackageName());

                    Uri uri = Uri.parse(String.format(getContext()
                            .getString(R.string.resource_sound),
                            getContext().getPackageName(), resId));

                    Log.d(TAG, "uri sound = " + uri);
                    try {
                        mMediaPlayer.reset();
                        mMediaPlayer.setDataSource(getContext(), uri);
                        mMediaPlayer.prepare();
                        mMediaPlayer.start();

                    } catch (IllegalStateException e) {
                        e.printStackTrace();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }

                }
            });

    builder.setPositiveButton("Ok", this);
    builder.setNegativeButton("Annuler", this);
}
于 2012-08-05T15:27:00.807 回答
2

这是自定义 ListPreference 的完整代码，就像铃声首选项一样：

import java.io.IOException;

import android.app.AlertDialog.Builder;
import android.content.Context;
import android.content.DialogInterface;
import android.content.res.Resources;
import android.content.res.TypedArray;
import android.database.Cursor;
import android.media.AudioManager;
import android.media.MediaPlayer;
import android.net.Uri;
import android.os.Parcel;
import android.os.Parcelable;
import android.preference.ListPreference;
import android.provider.MediaStore;
import android.util.AttributeSet;
import android.util.Log;

public class CustomListPreference extends ListPreference{

private MediaPlayer mMediaPlayer;
private Context mContext;
CharSequence[] mEntries;
CharSequence[] mEntryValues;
private int mClickedDialogEntryIndex;
private String mValue;

public CustomListPreference(Context context) {
    super(context);
    mContext = context;
}

/**
 * Sets the value of the key. This should be one of the entries in
 * {@link #getEntryValues()}.
 * 
 * @param value The value to set for the key.
 */
public void setValue(String value) {
    mValue = value;

    persistString(value);
}

/**
 * Sets the value to the given index from the entry values.
 * 
 * @param index The index of the value to set.
 */
public void setValueIndex(int index) {
    if (mEntryValues != null) {
        setValue(mEntryValues[index].toString());
    }
}

/**
 * Returns the value of the key. This should be one of the entries in
 * {@link #getEntryValues()}.
 * 
 * @return The value of the key.
 */
public String getValue() {
    return mValue; 
}

/**
 * Returns the entry corresponding to the current value.
 * 
 * @return The entry corresponding to the current value, or null.
 */
public CharSequence getEntry() {
    int index = getValueIndex();
    return index >= 0 && mEntries != null ? mEntries[index] : null;
}

 public int findIndexOfValue(String value) {
    if (value != null && mEntryValues != null) {
        for (int i = mEntryValues.length - 1; i >= 0; i--) {
            if (mEntryValues[i].equals(value)) {
                return i;
            }
        }
    }
    return -1;
}

private int  getValueIndex() {

    return findIndexOfValue(mValue);
}

@Override
protected void onPrepareDialogBuilder(Builder builder) {
    super.onPrepareDialogBuilder(builder);

    mMediaPlayer = new MediaPlayer();
    mEntries = getEntries();
    mEntryValues = getEntryValues();

    if (mEntries == null || mEntryValues == null) {
        throw new IllegalStateException(
                "ListPreference requires an entries array and an entryValues array.");
    }

    mClickedDialogEntryIndex = getValueIndex();
    builder.setSingleChoiceItems(mEntries, mClickedDialogEntryIndex,
            new DialogInterface.OnClickListener() {

                public void onClick(DialogInterface dialog, int which) {
                    mClickedDialogEntryIndex = which;

                    String value = mEntryValues[which].toString();
                    String path = findPathFromName(value);

                    try {
                        playSong(path);
                    } catch (IllegalStateException e) {
                        e.printStackTrace();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            });

    builder.setPositiveButton("Ok", this);
    builder.setNegativeButton("Cancel", this);
}

private void playSong(String path) throws IllegalArgumentException,
    IllegalStateException, IOException {

    Log.d("ringtone", "playSong :: " + path);

    mMediaPlayer.reset();
    mMediaPlayer.setDataSource(path);
    mMediaPlayer.setAudioStreamType(AudioManager.STREAM_RING);
//  mMediaPlayer.setLooping(true);
    mMediaPlayer.prepare();
    mMediaPlayer.start();
}


public String findPathFromName(String name) {
    Cursor mCursor = getContext().getContentResolver().query(
            MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, null, 
            MediaStore.Audio.Media.TITLE  + "='" +  name + "'", null, null );

    String path = "";
    if(mCursor.moveToFirst()){
        path = mCursor.getString(mCursor.getColumnIndex(MediaStore.Audio.Media.DATA));
    }

    mCursor.close();
    mCursor = null;

    return path;
}

@Override
protected void onRestoreInstanceState(Parcelable state) {
    if (state == null || !state.getClass().equals(SavedState.class)) {
        // Didn't save state for us in onSaveInstanceState
        super.onRestoreInstanceState(state);
        return;
    }

    SavedState myState = (SavedState) state;
    super.onRestoreInstanceState(myState.getSuperState());
    setValue(myState.value);
}

private static class SavedState extends BaseSavedState {
    String value;

    public SavedState(Parcel source) {
        super(source);
        value = source.readString();
    }

    @Override
    public void writeToParcel(Parcel dest, int flags) {
        super.writeToParcel(dest, flags);
        dest.writeString(value);
    }

    public SavedState(Parcelable superState) {
        super(superState);
    }

    public static final Parcelable.Creator<SavedState> CREATOR =
            new Parcelable.Creator<SavedState>() {
        public SavedState createFromParcel(Parcel in) {
            return new SavedState(in);
        }

        public SavedState[] newArray(int size) {
            return new SavedState[size];
        }
    };
}

 @Override
protected void onDialogClosed(boolean positiveResult) {
    super.onDialogClosed(positiveResult);

    if (positiveResult && mClickedDialogEntryIndex >= 0 && mEntryValues != null) {
        String value = mEntryValues[mClickedDialogEntryIndex].toString();
        if (callChangeListener(value)) {
            setValue(value);
        }
    }

    mMediaPlayer.stop();
    mMediaPlayer.release();
}

@Override
protected Object onGetDefaultValue(TypedArray a, int index) {
    return a.getString(index);
}

@Override
protected void onSetInitialValue(boolean restoreValue, Object defaultValue) {
    setValue(restoreValue ? getPersistedString(mValue) : (String) defaultValue);
}

@Override
protected Parcelable onSaveInstanceState() {
    final Parcelable superState = super.onSaveInstanceState();
    if (isPersistent()) {
        // No need to save instance state since it's persistent
        return superState;
    }

    final SavedState myState = new SavedState(superState);
    myState.value = getValue();
    return myState;
}
}

希望这对某人有所帮助。

于 2013-02-27T12:47:02.210 回答
0

在进行铃声偏好自定义时，我更喜欢铃声只播放一小段时间，有点像样本声音。如果他们只是从列表中选择声音，用户不需要听到整个声音播放。这是我实现这一目标的方法：

首先创建一个将播放铃声的服务（使用铃声管理器播放声音而不是媒体播放器，因为它为我们处理取消）：

公共类 PlayRingtoneService 扩展服务 { 静态铃声 r; 私有处理程序处理程序；

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
    //activating alarm sound
    if (r != null)
        r.stop();

    String filePath = intent.getStringExtra("uri");
    r = RingtoneManager.getRingtone(this, Uri.parse(filePath));
    r.play();

    handler.removeCallbacksAndMessages(null);

    handler.postDelayed(new Runnable() {
        @Override
        public void run() {
            if(r!=null)
                r.stop();
        }
    },6000L); //stop sound in 6 seconds

    return super.onStartCommand(intent, flags, startId);
}

void setThreadPriority(int priority) {

    try {
        Process.setThreadPriority(priority);
    } catch (Exception e) {
        Timber.e(e);
    }

}

@Override
public void onCreate() {
    super.onCreate();
     handler =new Handler();
    setThreadPriority(Process.THREAD_PRIORITY_URGENT_AUDIO);

}

@Override
public void onDestroy() {
    if (r != null)
        r.stop();
}

@Nullable
@Override
public IBinder onBind(Intent intent) {
    return null;
}

}

还使用服务更新清单：

<service android:name=".services.PlayRingtoneService" />

然后使用上面但修改的解决方案，您可以创建一个列表首选项，其行为就像铃声首选项：

public class CustomRingtoneListPreference extends ListPreference {

CharSequence[] mEntries;
CharSequence[] mEntryValues;
private int mClickedDialogEntryIndex;
private String mValue;

public CustomRingtoneListPreference(Context context) {
    super(context);
}


public CustomRingtoneListPreference(Context context, AttributeSet attrs) {
    super(context, attrs);
}

/**
 * Returns the value of the key. This should be one of the entries in
 * {@link #getEntryValues()}.
 *
 * @return The value of the key.
 */
public String getValue() {
    return mValue;
}

/**
 * Sets the value of the key. This should be one of the entries in
 * {@link #getEntryValues()}.
 *
 * @param value The value to set for the key.
 */
public void setValue(String value) {
    mValue = value;

    persistString(value);
}

/**
 * Returns the entry corresponding to the current value.
 *
 * @return The entry corresponding to the current value, or null.
 */
public CharSequence getEntry() {
    int index = getValueIndex();
    return index >= 0 && mEntries != null ? mEntries[index] : null;
}

public int findIndexOfValue(String value) {
    if (value != null && mEntryValues != null) {
        for (int i = mEntryValues.length - 1; i >= 0; i--) {
            if (mEntryValues[i].equals(value)) {
                return i;
            }
        }
    }
    return -1;
}

private int getValueIndex() {

    return findIndexOfValue(mValue);
}

/**
 * Sets the value to the given index from the entry values.
 *
 * @param index The index of the value to set.
 */
public void setValueIndex(int index) {
    if (mEntryValues != null) {
        setValue(mEntryValues[index].toString());
    }
}

@Override
protected void onPrepareDialogBuilder(AlertDialog.Builder builder) {
    super.onPrepareDialogBuilder(builder);
    mEntries = getEntries();
    mEntryValues = getEntryValues();

    if (mEntries == null || mEntryValues == null) {
        throw new IllegalStateException(
                "ListPreference requires an entries array and an entryValues array.");
    }

    mClickedDialogEntryIndex = getValueIndex();
    builder.setSingleChoiceItems(mEntries, mClickedDialogEntryIndex,
            new DialogInterface.OnClickListener() {

                public void onClick(DialogInterface dialog, int which) {
                    mClickedDialogEntryIndex = which;

                    String value = mEntryValues[which].toString();
                        playSong(value);
                }
            });

    builder.setPositiveButton("Ok", this);
    builder.setNegativeButton("Cancel", this);
}

private void playSong(String path) {
    Intent i = new Intent(getContext(), PlayRingtoneService.class);
    i.putExtra("uri", path);
    getContext().startService(i);

}

@Override
protected void onRestoreInstanceState(Parcelable state) {
    if (state == null || !state.getClass().equals(SavedState.class)) {
        // Didn't save state for us in onSaveInstanceState
        super.onRestoreInstanceState(state);
        return;
    }

    SavedState myState = (SavedState) state;
    super.onRestoreInstanceState(myState.getSuperState());
    setValue(myState.value);
}

@Override
protected void onDialogClosed(boolean positiveResult) {
    super.onDialogClosed(positiveResult);

    if (positiveResult && mClickedDialogEntryIndex >= 0 && mEntryValues != null) {
        String value = mEntryValues[mClickedDialogEntryIndex].toString();
        if (callChangeListener(value)) {
            setValue(value);
        }
    }

    Intent i = new Intent(getContext(), PlayRingtoneService.class);
    getContext().stopService(i);
}

@Override
protected Object onGetDefaultValue(TypedArray a, int index) {
    return a.getString(index);
}

@Override
protected void onSetInitialValue(boolean restoreValue, Object defaultValue) {

    setValue(restoreValue ? getPersistedString(mValue) : (String) defaultValue);
}

@Override
protected Parcelable onSaveInstanceState() {
    final Parcelable superState = super.onSaveInstanceState();
    if (isPersistent()) {
        // No need to save instance state since it's persistent
        return superState;
    }

    final SavedState myState = new SavedState(superState);
    myState.value = getValue();
    return myState;
}

private static class SavedState extends BaseSavedState {
    public static final Parcelable.Creator<SavedState> CREATOR =
            new Parcelable.Creator<SavedState>() {
                public SavedState createFromParcel(Parcel in) {
                    return new SavedState(in);
                }

                public SavedState[] newArray(int size) {
                    return new SavedState[size];
                }
            };
    String value;

    public SavedState(Parcel source) {
        super(source);
        value = source.readString();
    }

    public SavedState(Parcelable superState) {
        super(superState);
    }

    @Override
    public void writeToParcel(Parcel dest, int flags) {
        super.writeToParcel(dest, flags);
        dest.writeString(value);
    }
}

}

现在在你的 xml 中像这样使用它：

<mypackage.blah.blah.CustomRingtoneListPreference
            android:key="myRingtone"
            android:title="my title"
            android:summary="ringtone chosen %s"
            android:defaultValue="0"
            android:dependency="whatever you have"

            />

现在要将值实际加载到列表中，我们创建一个 utils 方法，该方法可以获取所有内部和外部媒体，并将其放入我们的模型类中，称为歌曲，定义如下：

public class Song {

private long id;
private Uri filePath;

private boolean externalPath;


/**
 * Creates a new Song, with specified `songID` and `filePath`.
 *
 * @note It's a unique Android identifier for a media file
 * anywhere on the system.
 */
public Song(long id, String title, String artist, Uri fileUri, boolean externalPath) {
    this.id = id;
    this.title = title;
    this.artist = artist;
    this.filePath = fileUri;
    this.externalPath = externalPath;
}

/**
 * Identifier for the song on the Android system.
 * (so we can locate the file anywhere)
 */
public long getId() {
    return id;
}


public Uri getFilePath() {
    return filePath;
}

public Song setFilePath(Uri filePath) {
    this.filePath = filePath;
    return this;
}

private String title = "";
private String artist = "";


public String getTitle() {
    return title;
}

public void setTitle(String title) {
    this.title = title;
}


public String getArtist() {
    return artist;
}

public void setArtist(String artist) {
    this.artist = artist;
}

public boolean isExternalPath() {
    return externalPath;
}

public Song setIsExternalPath(boolean externalPath) {
    this.externalPath = externalPath;
    return this;
}

}

现在在您的 Util 类中，或者如果您希望创建一个静态方法，该类将查询媒体存储中的所有音频文件：

public static List getAllExternalAudioSongs(Context c) { List songList = new ArrayList<>(); ContentResolver contentResolver = c.getContentResolver();

    List<Uri> contentUriLists = new ArrayList<>();
    contentUriLists.add(MediaStore.Audio.Media.INTERNAL_CONTENT_URI);
    contentUriLists.add(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI);
    String selection= MediaStore.Audio.Media.DURATION + ">= 3000";

    boolean externalPath = false;

    for (Uri uri : contentUriLists) {
        Cursor cursor = contentResolver.query(uri, null, selection, null, android.provider.MediaStore.Audio.Media.TITLE+ " ASC");
        if (cursor == null) {
            // query failed, handle error.
        } else if (!cursor.moveToFirst()) {
            // no media on the device
        } else {
            int titleColumn = cursor.getColumnIndex(android.provider.MediaStore.Audio.Media.TITLE);
            int idColumn = cursor.getColumnIndex(android.provider.MediaStore.Audio.Media._ID);
            int artistColumn = cursor.getColumnIndex(MediaStore.Audio.Media.ARTIST);

            do {
                long id = cursor.getLong(idColumn);
                String title = cursor.getString(titleColumn);
                String artist = cursor.getString(artistColumn);
                Uri contentUri = ContentUris.withAppendedId(
                        uri, id);
                Song song = new Song(id, title, artist, contentUri, externalPath);
                songList.add(song);
            } while (cursor.moveToNext());
            externalPath=true;
        }
    }
    return songList;
}

注意：externalPath 只是为了区分内部音频文件和外部音频文件。

最后，在preferenceActivity（或片段）的onCreate中，您可以这样做：

private void setRingtoneList() {

    ListPreference listPreferenceCategory = (ListPreference) findPreference("myRingtone");
    if (listPreferenceCategory != null) {
        List<Song> songList = Utils.getAllExternalAudioSongs(getApplicationContext());
        CharSequence entries[] = new String[songList.size()];
        CharSequence entryValues[] = new String[songList.size()];
        int i = 0;
        for (Song song : songList) {
            entries[i] = song.getTitle();
            entryValues[i] = song.getFilePath().toString();
            i++;
        }
        listPreferenceCategory.setEntries(entries);
        listPreferenceCategory.setEntryValues(entryValues);
    }
}

注意：您需要外部存储的运行时权限。并且要更新摘要，您必须在我相信的偏好活动中执行此操作。无论如何，这很好地说明了如何播放示例音频而不是整个音频文件。

于 2017-12-09T07:21:47.583 回答