android - 如何使用任何 "not Activity"中的铃声选择器(无 Activity)

Question

有没有办法在没有 Activity 的情况下使用铃声选择器？在我的案例中，这是来自 DialogPreference。

由于DialogPreference不是Activity，这里有两个问题:

1. 没有startActivityForResult
2. 没有 onActivityResult 方法。

我设法通过将构造函数中接收到的 Context 转换为 Activity 来使用 startActivityForResult，但我找不到捕获任何结果的方法。

作为变通方法，我使用来自 RingtoneManager 的铃声光标创建了带有 singleChoiceItems 设置的自定义 AlertDialog，但这不包括“默认铃声”、选定的铃声、不播放音乐，只是与默认铃声选择器“感觉不同”。

总而言之 - 是否有任何方法可以从 DialogPreference 运行铃声选择器，或者我是否需要创建整个自定义对话框？

编辑:那是我想出的自定义铃声选择器解决方案(问题仍然存在 - 如何使用默认铃声选择器？)。它有一些缺点(尤其是临时路径 - 如何修复它？)，但可能对某些人有用

// all this is inside some Dialog or other non Activity
Context mContext;
    // that is the string I want to get from Ringtone picker
    // something like  content://media/internal/audio/media/60
    // I can also get it stored version from somewhere else (preferences and such)
private String mRingtonePath = null; 

    // that is temp path I am using, because I can't find other way to store path 
    // received in setSingleChoiceItems onClickListener
private String mRingtoneTempPath = null;

void showRingtoneDialog() {
    RingtoneManager rm = new RingtoneManager(mContext);
    final Cursor ringtones = rm.getCursor();
    final MediaPlayer mp = new MediaPlayer();

    int selected = -1;

            // moving to proper ringtone in case some path was already supplied
    if (mRingtonePath != null)
        for (ringtones.moveToFirst(); !ringtones.isAfterLast(); ringtones
                .moveToNext()) {
            selected++;
            String path = ringtones
                    .getString(RingtoneManager.URI_COLUMN_INDEX)
                    + "/"
                    + ringtones.getInt(RingtoneManager.ID_COLUMN_INDEX);
            if (path.equals(mRingtonePath)) {
                break;
            }
        }

    AlertDialog.Builder builder = new AlertDialog.Builder(mContext);
    builder.setTitle("TITLE");
    builder.setSingleChoiceItems(ringtones, selected,
            ringtones.getColumnName(RingtoneManager.TITLE_COLUMN_INDEX),
            new DialogInterface.OnClickListener() {

                @Override
                public void onClick(DialogInterface dialog, int which) {
                    ringtones.moveToPosition(which);
                    String path = ringtones
                            .getString(RingtoneManager.URI_COLUMN_INDEX)
                            + "/"
                            + ringtones
                                    .getInt(RingtoneManager.ID_COLUMN_INDEX);
                    // ugly solution to store temp path
                                            setTempPathTo(path);
                    mp.reset();
                    try {
                        Uri uri = Uri.parse(path);
                        mp.setDataSource(mContext, uri);
                        mp.prepare();
                        mp.start();
                    } catch (Exception e) {
                        e.printStackTrace();
                    }

                }
            });
    builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            mp.reset();
            mp.release();

                            // I could read path nicely from here instead of using temp path,
                            // but ringtones Cursor somehow moves couple positions forward
                            // since last call to onClick in setSingleChoiceItems and 
            // String s = ringtones
            // .getString(RingtoneManager.URI_COLUMN_INDEX)
            // + "/"
            // + ringtones.getInt(RingtoneManager.ID_COLUMN_INDEX);
            mRingtonePath = mRingtoneTempPath;
        }
    });
    builder.setNegativeButton("Cancel",
            new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    mp.reset();
                    mp.release();
                }
            });
    AlertDialog alert = builder.create();
    alert.show();
}

void setTempPathTo(String path) {
    mRingtoneTempPath = path;
}

Answer 1

您需要的这两种方法都是 Context 类的一部分。只需将 getApplicationContext 传递到需要它的地方即可。