如何在具有 Oreo 及以上操作系統的 Android 設備中從 uri 獲取文件路徑

Question

要使用 Intent 選擇音頻文件，我正在使用此功能：-

fun selectAudioFromStorage() {
    val pictureActionIntent = Intent(Intent.ACTION_GET_CONTENT, null)
    pictureActionIntent.type = "audio/*"
    pictureActionIntent.putExtra("return-data", true)
    startActivityForResult(pictureActionIntent, ResultConstants.RC_SELECT_AUDIO)
}

片段類的 onActivityResult 提供所選音頻文件的 Uri，如下所示：

content://com.android.providers.downloads.documents/document/raw%3A%2Fstorage%2Femulated%2F0%2FDownload%2Forganfinale.mp3

在 Android (Lollipop) 上，使用光標將 uri 轉換為真實路徑可以正常工作，但對於 Oreo 設備，我無法從該音頻的 uri 中獲取真實路徑。

Answer 1

我解決了。 只需調用這個 getPathFromURI 方法，它就會返回文件路徑

object RealPathHelper {

private const val BUFFER_SIZE = 1024 * 2


@TargetApi(Build.VERSION_CODES.O)
fun getPathFromURI(
    context: Context,
    contentUri: Uri,
    fileNamePrefix: String,
    defaultFileExtension: String
): String? {
    val uriPath: String = contentUri.path ?: return null
    val fileName: String = MediaFileHelper.getFileNameWithExtension(uriPath)

    if (fileName.isNotBlank()) {
        val destFile =
            createOutputFile(context, contentUri, fileNamePrefix, defaultFileExtension)
        copyUriToFile(context, contentUri, destFile)
        return destFile.absolutePath
    }
    return null
}

private fun createOutputFile(
    context: Context,
    contentUri: Uri,
    fileNamePrefix: String,
    defaultFileExtension: String
): File {
    var count = 0
    var file: File

    val uriPath: String? = contentUri.path
    val fileExtension = if (uriPath == null) defaultFileExtension
    else MediaFileHelper.getFileExtension(uriPath)

    do {
        count++

        val mFileName = "$fileNamePrefix${StringHelper.getUniqueId()}$count$fileExtension"
        val newFilePath =
            "${context.getExternalFilesDir(null)?.absolutePath}${context.getString(R.string.audio_select_directory)}/$mFileName"

        file = File(newFilePath)

    } while (file.exists() && !file.isDirectory)

    return file
}

private fun copyUriToFile(context: Context, srcUri: Uri, dstFile: File) {
    try {
        val inputStream = context.contentResolver.openInputStream(srcUri) ?: return
        val outputStream = FileOutputStream(dstFile)
        inputStream.copyTo(outputStream, BUFFER_SIZE)
        inputStream.close()
        outputStream.close()
    } catch (e: IOException) {
        e.printStackTrace()
    }
}

Answer 2

由於文件路徑在 API 29 及更高版本中不可用於公共文件，我建議您不要嘗試使用它們，而是使用 Java FileDescriptor 。

根據https://developer.android.com/training/data-storage#scoped-storage

更具體地說https://developer.android.com/training/data-storage/shared/media#open-file-descriptor

許多 API 允許您提供FileDescriptor而不是路徑。

例如使用https://developer.android.com/reference/android/media/MediaPlayer.html#setDataSource(java.io.FileDescriptor)

代替

https://developer.android.com/reference/android/media/MediaPlayer.html#setDataSource(java.lang.String)

要從 URI 獲取fileDescriptor ，請執行以下操作（在 Java 中）

ParcelFileDescriptor pfd =
                this.getContentResolver().
                        openFileDescriptor(URI, "r");

FileDescriptor fileDescriptor = pfd.getFileDescriptor();

Answer 3

我通常使用這個類來獲取路徑，你可以看看這個幾乎適用於所有版本

public class RealPathUtil {

    public static String getRealPath(Context context, Uri fileUri) {
        String realPath;
        // SDK < API11
        if (Build.VERSION.SDK_INT < 11) {
            realPath = RealPathUtil.getRealPathFromURI_BelowAPI11(context, fileUri);
        }
        // SDK >= 11 && SDK < 19
        else if (Build.VERSION.SDK_INT < 19) {
            realPath = RealPathUtil.getRealPathFromURI_API11to18(context, fileUri);
        }
        // SDK > 19 (Android 4.4) and up
        else {
            realPath = RealPathUtil.getRealPathFromURI_API19(context, fileUri);
        }
        return realPath;
    }


    @SuppressLint("NewApi")
    public static String getRealPathFromURI_API11to18(Context context, Uri contentUri) {
        String[] proj = {MediaStore.Images.Media.DATA};
        String result = null;

        CursorLoader cursorLoader = new CursorLoader(context, contentUri, proj, null, null, null);
        Cursor cursor = cursorLoader.loadInBackground();

        if (cursor != null) {
            int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
            cursor.moveToFirst();
            result = cursor.getString(column_index);
            cursor.close();
        }
        return result;
    }

    public static String getRealPathFromURI_BelowAPI11(Context context, Uri contentUri) {
        String[] proj = {MediaStore.Images.Media.DATA};
        Cursor cursor = context.getContentResolver().query(contentUri, proj, null, null, null);
        int column_index = 0;
        String result = "";
        if (cursor != null) {
            column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
            cursor.moveToFirst();
            result = cursor.getString(column_index);
            cursor.close();
            return result;
        }
        return result;
    }

    /**
     * Get a file path from a Uri. This will get the the path for Storage Access
     * Framework Documents, as well as the _data field for the MediaStore and
     * other file-based ContentProviders.
     *
     * @param context The context.
     * @param uri     The Uri to query.
     * @author paulburke
     */
    @SuppressLint("NewApi")
    public static String getRealPathFromURI_API19(final Context context, final Uri uri) {

        final boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;

        // DocumentProvider
        if (isKitKat && DocumentsContract.isDocumentUri(context, uri)) {
            // ExternalStorageProvider
            if (isExternalStorageDocument(uri)) {
                final String docId = DocumentsContract.getDocumentId(uri);
                final String[] split = docId.split(":");
                final String type = split[0];

                if ("primary".equalsIgnoreCase(type)) {
                    return Environment.getExternalStorageDirectory() + "/" + split[1];
                }

                // TODO handle non-primary volumes
            }
            // DownloadsProvider
            else if (isDownloadsDocument(uri)) {

                final String id = DocumentsContract.getDocumentId(uri);
                final Uri contentUri = ContentUris.withAppendedId(
                        Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));

                return getDataColumn(context, contentUri, null, null);
            }
            // MediaProvider
            else if (isMediaDocument(uri)) {
                final String docId = DocumentsContract.getDocumentId(uri);
                final String[] split = docId.split(":");
                final String type = split[0];

                Uri contentUri = null;
                if ("image".equals(type)) {
                    contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
                } else if ("video".equals(type)) {
                    contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
                } else if ("audio".equals(type)) {
                    contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
                }

                final String selection = "_id=?";
                final String[] selectionArgs = new String[]{
                        split[1]
                };

                return getDataColumn(context, contentUri, selection, selectionArgs);
            }
        }
        // MediaStore (and general)
        else if ("content".equalsIgnoreCase(uri.getScheme())) {

            // Return the remote address
            if (isGooglePhotosUri(uri))
                return uri.getLastPathSegment();

            return getDataColumn(context, uri, null, null);
        }
        // File
        else if ("file".equalsIgnoreCase(uri.getScheme())) {
            return uri.getPath();
        }

        return null;
    }

    /**
     * Get the value of the data column for this Uri. This is useful for
     * MediaStore Uris, and other file-based ContentProviders.
     *
     * @param context       The context.
     * @param uri           The Uri to query.
     * @param selection     (Optional) Filter used in the query.
     * @param selectionArgs (Optional) Selection arguments used in the query.
     * @return The value of the _data column, which is typically a file path.
     */
    public static String getDataColumn(Context context, Uri uri, String selection,
                                       String[] selectionArgs) {

        Cursor cursor = null;
        final String column = "_data";
        final String[] projection = {
                column
        };

        try {
            cursor = context.getContentResolver().query(uri, projection, selection, selectionArgs,
                    null);
            if (cursor != null && cursor.moveToFirst()) {
                final int index = cursor.getColumnIndexOrThrow(column);
                return cursor.getString(index);
            }
        } finally {
            if (cursor != null)
                cursor.close();
        }
        return null;
    }


    /**
     * @param uri The Uri to check.
     * @return Whether the Uri authority is ExternalStorageProvider.
     */
    public static boolean isExternalStorageDocument(Uri uri) {
        return "com.android.externalstorage.documents".equals(uri.getAuthority());
    }

    /**
     * @param uri The Uri to check.
     * @return Whether the Uri authority is DownloadsProvider.
     */
    public static boolean isDownloadsDocument(Uri uri) {
        return "com.android.providers.downloads.documents".equals(uri.getAuthority());
    }

    /**
     * @param uri The Uri to check.
     * @return Whether the Uri authority is MediaProvider.
     */
    public static boolean isMediaDocument(Uri uri) {
        return "com.android.providers.media.documents".equals(uri.getAuthority());
    }

    /**
     * @param uri The Uri to check.
     * @return Whether the Uri authority is Google Photos.
     */
    public static boolean isGooglePhotosUri(Uri uri) {
        return "com.google.android.apps.photos.content".equals(uri.getAuthority());
    }

}

參考： https : //gist.github.com/tatocaster/32aad15f6e0c50311626