如何使用 java 从 Android 10 中的外部存储中获取所有带有 FileName 的 PDF 文件 Uri

Question

我正在尝试列出应用程序创建的外部存储中的所有 PDF 文件。遍历光标后如何在App中列出pdf文件？

private void getExternalPDFFiles() {

    ContentResolver cr = getContentResolver();
    Uri uri = MediaStore.Files.getContentUri("external");

    // every column, although that is huge waste, you probably need
    // BaseColumns.DATA (the path) only.
    String[] projection = null;

    // exclude media files, they would be here also.
    String selection = MediaStore.Files.FileColumns.MEDIA_TYPE + "="
            + MediaStore.Files.FileColumns.MEDIA_TYPE;
    String[] selectionArgs = null; // there is no ? in selection so null here

    String sortOrder = null; // unordered
    //        Cursor allNonMediaFiles = cr.query(uri, projection, selection, selectionArgs, sortOrder);


    // only pdf
    String selectionMimeType = MediaStore.Files.FileColumns.MIME_TYPE + "=?";
    String mimeType = MimeTypeMap.getSingleton().getMimeTypeFromExtension("pdf");
    String[] selectionArgsPdf = new String[]{mimeType};
    Cursor cursor = cr.query(uri, projection, selectionMimeType, selectionArgsPdf, sortOrder);
    assert cursor != null;
    if (cursor.moveToFirst()) {
        while (!cursor.isAfterLast()) {
            //your code to implement
            Log.d("TAG", cursor.getColumnNames().toString());
            cursor.moveToNext();
        }
    }
    Log.d("TAG", cursor.getCount() + "");
    Log.d("TAG", cursor.getColumnCount() + "");
    cursor.close();

}

Answer 1

获取Android-10及以上所有包含Uri和FileName的文件列表：

class FileModel {
    String displayName;
    Uri fileUri;

    FileModel(String displayName, Uri fileUri) {
        this.displayName = displayName;
        this.fileUri = fileUri;
    }
}

...

private ArrayList<FileModel> getExternalPDFFileList() {

    ContentResolver cr = getContentResolver();
    Uri uri = MediaStore.Files.getContentUri("external");

    String[] projection = {MediaStore.Files.FileColumns._ID, MediaStore.Files.FileColumns.DISPLAY_NAME};
    String selection = MediaStore.Files.FileColumns.MEDIA_TYPE + "="
            + MediaStore.Files.FileColumns.MEDIA_TYPE;
    String[] selectionArgs = null;
    String selectionMimeType = MediaStore.Files.FileColumns.MIME_TYPE + "=?";
    String mimeType = MimeTypeMap.getSingleton().getMimeTypeFromExtension("pdf");
    String[] selectionArgsPdf = new String[]{mimeType};

    Cursor cursor = cr.query(uri, projection, selectionMimeType, selectionArgsPdf, null);

    assert cursor != null;
    ArrayList<FileModel> uriList = new ArrayList<>();
    for (cursor.moveToFirst(); !cursor.isAfterLast(); cursor.moveToNext()) {
        int columnIndex = cursor.getColumnIndex(projection[0]);
        long fileId = cursor.getLong(columnIndex);
        Uri fileUri = Uri.parse(uri.toString() + "/" + fileId);
        String displayName = cursor.getString(cursor.getColumnIndex(projection[1]));
        uriList.add(new FileModel(displayName, fileUri));
    }
    cursor.close();
    return uriList;
}

如何使用 java 从 Android 10 中的外部存储中获取所有带有 FileName 的 PDF 文件 Uri

How to get all PDF files Uri with FileName from external storage in Android 10 using java

file

android-cursor

mediastore

android-10.0

android-external-storage