Question

我正在选择PDF并将其上传到服务器。从下载中选择文件时，以下代码崩溃。如果文件从任何其他目录中选择，也可以正常工作。

我尝试在具有（android 9）Pie OS的oneplus 6和nokia 6.1上使用以下代码。

简单的代码，意图活动开始：

Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
intent.setType("application/pdf");
intent.addCategory(Intent.CATEGORY_OPENABLE);
startActivityForResult(Intent.createChooser(intent, "Select file"), 2);

在onActivityResult

if (resultCode == Activity.RESULT_OK) {
   boolean isError = false;
   Uri selectedURI = data.getData();
   String docPath = getPath(selectedURI);
....
}

这是整个代码getPath(Uri uri)

private String getPath(final Uri uri) {
        final boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;
        if(isKitKat) {
            return getForApi19(uri);
        } else if ("content".equalsIgnoreCase(uri.getScheme())) {
            if (isGooglePhotosUri(uri))
                return uri.getLastPathSegment();

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

    @TargetApi(19)
    private String getForApi19(Uri uri) {
        if (DocumentsContract.isDocumentUri(this.getActivity(), uri)) {
            // ExternalStorageProvider
            if (isExternalStorageDocument(uri)) {
                final String docId = DocumentsContract.getDocumentId(uri);
                if (docId.startsWith("raw:")) {
                    return docId.replaceFirst("raw:", "");
                }
                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);
                if (id.startsWith("raw:")) {
                    return id.replaceFirst("raw:", "");
                }
                String[] contentUriPrefixesToTry = new String[]{
                        "content://downloads/my_downloads",
                        "content://downloads/public_downloads",
                        "content://downloads/all_downloads"
                };

                for (String contentUriPrefix : contentUriPrefixesToTry) {
                    Uri contentUri = ContentUris.withAppendedId(Uri.parse(contentUriPrefix), Long.valueOf(id));
                    try {
                        String path = getDataColumn(contentUri, null, null);
                        if (path != null) {
                            return path;
                        }
                    } catch (Exception e) {}
                }
            }
            // MediaProvider
            else if (isMediaDocument(uri)) {
                final String docId = DocumentsContract.getDocumentId(uri);
                if (docId.startsWith("raw:")) {
                    return docId.replaceFirst("raw:", "");
                }
                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(contentUri, selection, selectionArgs);
            }
        } else if ("content".equalsIgnoreCase(uri.getScheme())) {

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

            return getDataColumn(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 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 String getDataColumn(Uri uri, String selection,
                                String[] selectionArgs) {

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

        try {
            cursor = this.getActivity().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.isClosed())
                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());
    }

仅content://downloads/my_downloads返回Curser对象。其他content://downloads/public_downloads和content://downloads/all_downloads返回null。

问题：

从Downloads中选择文件时，Cursor.moveToFirst()为假。而且我没有文件路径。

Answer 1

我有同样的问题，

将以下代码用于

if (isDownloadsDocument(uri)) {
                String fileName = getFilePath(context, uri);
                if (fileName != null) {
                    return Environment.getExternalStorageDirectory().toString() + "/Download/" + fileName;
                }

                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);
            }

和getFilePath（）

public static String getFilePath(Context context, Uri uri) {

        Cursor cursor = null;
        final String[] projection = {
                MediaStore.MediaColumns.DISPLAY_NAME
        };

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

引用：This link

ACTION_GET_CONTENT从下载中选择文档返回空值

1 个答案: