android - 在android q中如何获取android文档目录的路径？

Question

我正在努力寻找这个问题的明确答案。我知道这涉及到使用媒体商店，但我不太明白。

谢谢。

编辑:如果有帮助，我目前正在使用 Pixel 2。

Answer 1

如果您的目标是 Android 11 API，则无法直接访问文件路径，因为 API 30(Android R) 中有很多限制。由于在 Android 10(API 29) 中引入了 scoped storage API，现在存储分为 scoped storage(私有(private)存储)和 共享存储(公共(public)存储)。范围存储是一种您只能访问在范围存储目录(即/Android/data/或/Android/media/)中创建的文件的类型。您无法从共享存储(即内部存储/外部 SD 卡存储等)访问文件

共享存储再次进一步分为媒体和下载集合。媒体收藏存储图像、音频和视频文件。下载集合将处理非媒体文件。

要了解有关分区存储和共享存储的更多详细信息，请参阅此链接- Scoped Storage in Android 10 & Android 11 .

为了获取文档目录路径，我创建了 URI utils 类，它将从 URI 获取文件的路径。

    import android.content.ContentUris
    import android.content.Context
    import android.database.Cursor
    import android.net.Uri
    import android.os.Build
    import android.os.Environment
    import android.provider.DocumentsContract
    import android.provider.MediaStore
    import android.provider.OpenableColumns
    import android.util.Log
    import android.widget.Toast
    import java.io.File
    import java.io.FileOutputStream
    
    class UriPathUtils
    {
        fun getRealPathFromURI(context: Context, uri: Uri): String? {
            when {
                // DocumentProvider
                DocumentsContract.isDocumentUri(context, uri) -> {
                    when {
                        // ExternalStorageProvider
                        isExternalStorageDocument(uri) -> {
                            //Toast.makeText(context, "From Internal & External Storage dir", Toast.LENGTH_SHORT).show()
                            val docId = DocumentsContract.getDocumentId(uri)
                            val split = docId.split(":").toTypedArray()
                            val type = split[0]
                            // This is for checking Main Memory
                            return if ("primary".equals(type, ignoreCase = true)) {
                                if (split.size > 1) {
                                    Environment.getExternalStorageDirectory().toString() + "/" + split[1]
                                } else {
                                    Environment.getExternalStorageDirectory().toString() + "/"
                                }
                                // This is for checking SD Card
                            } else {
                                "storage" + "/" + docId.replace(":", "/")
                            }
                        }
                        isDownloadsDocument(uri) -> {
                            //Toast.makeText(context, "From Downloads dir", Toast.LENGTH_SHORT).show()
                            val fileName = getFilePath(context, uri)
                            if (fileName != null) {
                                return Environment.getExternalStorageDirectory().toString() + "/Download/" + fileName
                            }
                            var id = DocumentsContract.getDocumentId(uri)
                            if (id.startsWith("raw:")) {
                                id = id.replaceFirst("raw:".toRegex(), "")
                                val file = File(id)
                                if (file.exists()) return id
                            }
                            val contentUri = ContentUris.withAppendedId(Uri.parse("content://downloads/public_downloads"), java.lang.Long.valueOf(id))
                            return getDataColumn(context, contentUri, null, null)
                        }
                        isMediaDocument(uri) -> {
                            //Toast.makeText(context, "From Documents dir", Toast.LENGTH_SHORT).show()
                            val docId = DocumentsContract.getDocumentId(uri)
                            val split = docId.split(":").toTypedArray()
                            val type = split[0]
                            var contentUri: Uri? = null
                            when (type) {
                                "image" -> {
                                    contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI
                                }
                                "video" -> {
                                    contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI
                                }
                                "audio" -> {
                                    contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI
                                }
                                else -> {
                                    //non-media files i.e documents and other files
                                    contentUri = MediaStore.Files.getContentUri("external")
                                    val selection = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
                                        MediaStore.MediaColumns.RELATIVE_PATH + "=?"
                                    } else "_id=?"
                                    val selectionArgs = arrayOf(Environment.DIRECTORY_DOCUMENTS)
                                    return getMediaDocumentPath(context, contentUri,selection,selectionArgs)
                                }
                            }
                            val selection = "_id=?"
                            val selectionArgs = arrayOf(split[1])
                            return getDataColumn(context, contentUri, selection, selectionArgs)
                        }
                        isGoogleDriveUri(uri) -> {
                            Toast.makeText(context, "From Google Drive", Toast.LENGTH_SHORT).show()
                            return getDriveFilePath(uri, context)
                        }
                        /*else -> {
                            Toast.makeText(context, "Unknown Directory", Toast.LENGTH_SHORT).show()
                        }*/
                    }
                }
                "content".equals(uri.scheme, ignoreCase = true) -> {
                    //Toast.makeText(context, "From Content Uri", Toast.LENGTH_SHORT).show()
                    // Return the remote address
                    return if (isGooglePhotosUri(uri)) uri.lastPathSegment else getDataColumn(context, uri, null, null)
                }
                "file".equals(uri.scheme, ignoreCase = true) -> {
                    //Toast.makeText(context, "From File Uri", Toast.LENGTH_SHORT).show()
                    return uri.path
                }
            }
            return null
        }
    
        private fun getDataColumn(context: Context, uri: Uri?, selection: String?, selectionArgs: Array<String>?): String? {
            var cursor: Cursor? = null
            val column = "_data"
            val projection = arrayOf(column)
            try {
                if (uri == null) return null
                cursor = context.contentResolver.query(uri, projection, selection, selectionArgs, null)
                if (cursor != null && cursor.moveToFirst()) {
                    val index = cursor.getColumnIndexOrThrow(column)
                    return cursor.getString(index)
                }
            } finally {
                cursor?.close()
            }
            return null
        }
    
        private fun getMediaDocumentPath(context: Context, uri: Uri?,selection: String?, selectionArgs: Array<String>?): String? {
            var cursor: Cursor? = null
            val column = "_data"
            val projection = arrayOf(column)
            try {
                if (uri == null) return null
                cursor = context.contentResolver.query(uri, projection, selection, selectionArgs, null)
                if (cursor != null && cursor.moveToFirst()) {
                    val index = cursor.getColumnIndexOrThrow(column)
                    //Toast.makeText(context, "From Media Document --- Non Media Path ${cursor.getString(index)} ", Toast.LENGTH_SHORT).show()
                    return cursor.getString(index)
                }
            } finally {
                cursor?.close()
            }
            return null
        }
    
        private fun getFilePath(context: Context, uri: Uri?): String? {
            var cursor: Cursor? = null
            val projection = arrayOf(MediaStore.MediaColumns.DISPLAY_NAME)
            try {
                if (uri == null) return null
                cursor = context.contentResolver.query(uri, projection, null, null,
                    null)
                if (cursor != null && cursor.moveToFirst()) {
                    val index = cursor.getColumnIndexOrThrow(MediaStore.MediaColumns.DISPLAY_NAME)
                    return cursor.getString(index)
                }
            } finally {
                cursor?.close()
            }
            return null
        }
    
        private fun getDriveFilePath(uri: Uri, context: Context): String? {
            val returnCursor = context.contentResolver.query(uri, null, null, null, null)
            val nameIndex = returnCursor!!.getColumnIndex(OpenableColumns.DISPLAY_NAME)
            val sizeIndex = returnCursor.getColumnIndex(OpenableColumns.SIZE)
            returnCursor.moveToFirst()
            val name = returnCursor.getString(nameIndex)
            val size = returnCursor.getLong(sizeIndex).toString()
            val file = File(context.cacheDir, name)
            try {
                val inputStream = context.contentResolver.openInputStream(uri)
                val outputStream = FileOutputStream(file)
                var read = 0
                val maxBufferSize = 1 * 1024 * 1024
                val bytesAvailable = inputStream!!.available()
    
                //int bufferSize = 1024;
                val bufferSize = Math.min(bytesAvailable, maxBufferSize)
                val buffers = ByteArray(bufferSize)
                while (inputStream.read(buffers).also { read = it } != -1) {
                    outputStream.write(buffers, 0, read)
                }
                Log.e("File Size", "Size " + file.length())
                inputStream.close()
                outputStream.close()
                Log.e("File Path", "Path " + file.path)
                Log.e("File Size", "Size " + file.length())
            } catch (e: Exception) {
                Log.e("Exception", e.message!!)
            }
            return file.path
        }
    
        /**
         * @param uri The Uri to check.
         * @return Whether the Uri authority is ExternalStorageProvider.
         */
        private fun isExternalStorageDocument(uri: Uri): Boolean {
            return "com.android.externalstorage.documents" == uri.authority
        }
    
        /**
         * @param uri The Uri to check.
         * @return Whether the Uri authority is DownloadsProvider.
         */
        private fun isDownloadsDocument(uri: Uri): Boolean {
            return "com.android.providers.downloads.documents" == uri.authority
        }
    
        /**
         * @param uri The Uri to check.
         * @return Whether the Uri authority is MediaProvider.
         */
        private fun isMediaDocument(uri: Uri): Boolean {
            return "com.android.providers.media.documents" == uri.authority
        }
    
        /**
         * @param uri The Uri to check.
         * @return Whether the Uri authority is Google Photos.
         */
        private fun isGooglePhotosUri(uri: Uri): Boolean {
            return "com.google.android.apps.photos.content" == uri.authority
        }
    
        /**
         * @param uri The Uri to check.
         * @return Whether the Uri authority is Google Photos.
         */
        private fun isGoogleDriveUri(uri: Uri): Boolean {
            return "com.google.android.apps.docs.storage" == uri.authority || "com.google.android.apps.docs.storage.legacy" == uri.authority
        }
}

这个 utils 类将帮助您获取文件路径，只需调用这一行 ..

contentUri.let { UriPathUtils().getRealPathFromURI(this, it).toString() }

干杯...!