android - 如何检测Android上的哪个存储空间，其中存在图像

Question

我正在构建类似图片库应用程序的东西。但是当我使用下面的代码在 Android 设备上检索图像时，我似乎不知道图像是否存在于设备的主要外部存储（内部存储器）或辅助外部存储（SD 卡）中。我将如何区分这两者？

我的代码如下

// root_extra was gotten from the starter of this activity. It can either be MediaStore.Images.Media.EXTERNAL_CONTENT_URI or MediaStore.Images.Media.INTERNAL_CONTENT_URI based on whichever storage location user wants to access by clicking either of two buttons available in the starter activity (Phone storage and SD card)
     String root_extra = getIntent().getStringExtra(STORAGE_ACCESS_ROOT);
            Uri storageUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
            if (root_extra != null) {
                storageUri = root_extra.equals(EXTERNAL) ? MediaStore.Images.Media.EXTERNAL_CONTENT_URI
                        : MediaStore.Images.Media.INTERNAL_CONTENT_URI;
            }
    
            String[] projection = {
                    MediaStore.Images.Media._ID,
                    MediaStore.Images.Media.BUCKET_DISPLAY_NAME,
                    MediaStore.Images.Media.SIZE,
                    MediaStore.Images.Media.DISPLAY_NAME};
            Cursor imgCursor = getApplicationContext()
                    .getContentResolver()
                    .query(storageUri, projection, null, null, null);
    
            int bucketId = imgCursor.getColumnIndexOrThrow(MediaStore.Images.Media._ID);
            int imgSize = imgCursor.getColumnIndexOrThrow(MediaStore.Images.Media.SIZE);
            int name = imgCursor.getColumnIndexOrThrow(MediaStore.Images.Media.DISPLAY_NAME);
            int bucketName
                    = imgCursor.getColumnIndexOrThrow(MediaStore.Images.Media.BUCKET_DISPLAY_NAME);
    
            List<String> dirName = new ArrayList<>();
            while (imgCursor.moveToNext()) {
                long id = imgCursor.getLong(bucketId);
                int size = imgCursor.getInt(imgSize);
                String fileName = imgCursor.getString(name);
                String folderName = imgCursor.getString(bucketName);
    
                Uri contentUri
                        = ContentUris.withAppendedId(storageUri, id);
                Image currentImage = new Image(contentUri, size, fileName, folderName);
    
                int directoryIndex = linearSearch(dirName, folderName);
                // if search result (directoryIndex) passes this test, then it means that there is
                // no such directory in list of directory names
                if (directoryIndex < 0) {
                    imageDirectoryList.add(new ArrayList<>());
                    dirName.add(folderName);
                    directoryIndex = linearSearch(dirName, folderName);
                    if (directoryIndex >= 0)
                        imageDirectoryList.get(directoryIndex).add(currentImage);
                } else {
                    imageDirectoryList.get(directoryIndex).add(currentImage);
                }
            }
    
            imgCursor.close();
            runOnUiThread(() -> {
                imageAdapter.notifyDataSetChanged();
                doViewUpdate();
            });

我MediaStore.Images.Media.INTERNAL_CONTENT_URI用来访问主外部存储（或我称之为内部存储器），但它不起作用。

标签： androidstorageandroid-sdcardmediastore