我尝试添加音频文件，val values = ContentValues().apply {

put(MediaStore.Audio.Media.RELATIVE_PATH, libraryPart.rootFolderRelativePath) // JDrop/1/1

put(MediaStore.Audio.Media.DISPLAY_NAME, remoteLibraryEntry.getFilename()) //12.mp3

put(MediaStore.Audio.Media.IS_PENDING, 1)

if(mimeType != null)

put(MediaStore.Audio.Media.MIME_TYPE, mimeType) // audio/mpeg3

}

val collection = MediaStore.Audio.Media

.getContentUri(MediaStore.VOLUME_EXTERNAL_PRIMARY)

var uri = ctx.contentResolver.insert(collection, values) // returns null for around 300/2000 files consistently

尝试插入新文件时Logcat输出如下。2020-01-24 22:27:33.724 4015-7707/? E/SQLiteDatabase: Error inserting title_key= bucket_display_name=1 owner_package_name=shio.at.jdrop parent=79657 volume_name=external_primary title_resource_uri=null _display_name=12.mp3 mime_type=audio/mpeg3 _data=/storage/emulated/0/Music/JDrop/1/1/12.mp3 title= group_id=1569 artist_id=322 is_pending=1 date_added=1579901253 album_id=2958 primary_directory=Music secondary_directory=JDrop bucket_id=687581593 media_type=2 relative_path=Music/JDrop/1/1/ from {P:30220;U:10165}

android.database.sqlite.SQLiteConstraintException: UNIQUE constraint failed: files._data (code 2067 SQLITE_CONSTRAINT_UNIQUE)

at android.database.sqlite.SQLiteConnection.nativeExecuteForLastInsertedRowId(Native Method)

at android.database.sqlite.SQLiteConnection.executeForLastInsertedRowId(SQLiteConnection.java:879)

at android.database.sqlite.SQLiteSession.executeForLastInsertedRowId(SQLiteSession.java:790)

at android.database.sqlite.SQLiteStatement.executeInsert(SQLiteStatement.java:88)

at android.database.sqlite.SQLiteDatabase.insertWithOnConflict(SQLiteDatabase.java:1639)

at android.database.sqlite.SQLiteDatabase.insert(SQLiteDatabase.java:1494)

at com.android.providers.media.MediaProvider.insertFile(MediaProvider.java:3050)

at com.android.providers.media.MediaProvider.insertInternal(MediaProvider.java:3452)

at com.android.providers.media.MediaProvider.insert(MediaProvider.java:3240)

at android.content.ContentProvider$Transport.insert(ContentProvider.java:325)

at android.content.ContentProviderNative.onTransact(ContentProviderNative.java:164)

at android.os.Binder.execTransactInternal(Binder.java:1032)

at android.os.Binder.execTransact(Binder.java:1005)

files._data表示文件已经存在于MediaStore。JDrop/1/1/12.mp3上没有文件，它只是在MediaStore中，需要删除它，或者为现有OutputStream获取一个MediaStore，

我尝试使用下面的代码在ID中查询MediaStore，但是没有成功，if(uri == null) {

val id: Long = ctx.contentResolver.query(

collection,

arrayOf(BaseColumns._ID),

"${MediaStore.Audio.Media.RELATIVE_PATH}=? AND ${MediaStore.Audio.Media.DISPLAY_NAME}=?",

arrayOf(libraryPart.rootFolderRelativePath, remoteLibraryEntry.getFilename()),

null)?.use {

if (it.moveToNext())

it.getLong(it.getColumnIndex(BaseColumns._ID))

else null

} ?: return false

uri = Uri.withAppendedPath(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, id!!.toString())

}

我现在还尝试用硬编码的路径对_data进行查询，没有成功。val id: Long = ctx.contentResolver.query(

collection,

arrayOf(BaseColumns._ID),

"${MediaStore.Audio.Media.DATA}=?",

arrayOf("/storage/emulated/0/Music/JDrop/1/1/12.mp3"),

null)?.use {

if (it.moveToNext())

it.getLong(it.getColumnIndex(BaseColumns._ID))

else null

} ?: return false

获取null并返回false。(查询所有内容并查看返回的内容)

我试图对entier集合执行一个小的测试查询，class TestQueryObject(val id: Long, val relativePath: String, val displayName: String)

val results = mutableListOf()

ctx.contentResolver.query(

collection,

arrayOf(MediaStore.Audio.Media._ID, MediaStore.Audio.Media.RELATIVE_PATH, MediaStore.Audio.Media.DISPLAY_NAME),

null,

null,

null)?.use {

while (it.moveToNext()) {

results.add(TestQueryObject(

id = it.getLong(it.getColumnIndex(MediaStore.Audio.Media._ID)),

relativePath = it.getString(it.getColumnIndex(MediaStore.Audio.Media.RELATIVE_PATH)),

displayName = it.getString(it.getColumnIndex(MediaStore.Audio.Media.DISPLAY_NAME))

))

}

}

var find12 = results.find { it.displayName =="12.mp3" }

它返回2557个条目的列表，但是find12仍然是空的。