Question

我有这个查询来获取非媒体文件，我想获得光标的正确列但我无法获得列

    Uri uri = MediaStore.Files.getContentUri("external");
    String[] projection = null;
    String selectionMimeType = MediaStore.Files.FileColumns.MIME_TYPE + "=?";
    String mimeType = MimeTypeMap.getSingleton().getMimeTypeFromExtension("pdf");
    String[] selectionArgsPdf = new String[]{mimeType};
    String sortOrder = MediaStore.Files.FileColumns.MIME_TYPE; // unordered
    final Cursor allNonMediaFiles = managedQuery(uri, projection, selectionMimeType, selectionArgsPdf, sortOrder);

我正在使用此代码获取列并获取其中的所有数据，但它无法返回值

    int file_column_index = allNonMediaFiles.getColumnIndex(MediaStore.Files.FileColumns._ID);
    this.fileCount = allNonMediaFiles.getCount();
    this.pdf = new String[this.fileCount];
    this.pdfPath = new String[this.fileCount];
    for (int i = 0; i < this.fileCount; i++) {
        int pdfColumnIndex = allNonMediaFiles.getColumnIndex(MediaStore.Files.FileColumns.TITLE);
        pdfPath[i] = allNonMediaFiles.getString(pdfColumnIndex);
    }

Answer 1

确保在遍历游标项目之前执行 cursor.moveToFirst（）。

下面的代码工作正常

final Cursor allNonMediaFiles =（getBaseContext（）。getContentResolver（））。query（uri，projection，selectionMimeType，selectionArgsPdf，sortOrder）;

的 allNonMediaFiles.moveToFirst（）; 的

int file_column_index = allNonMediaFiles.getColumnIndex（MediaStore.Files.FileColumns._ID）;

...

Answer 2

最后我弄清楚我需要做的就是将光标放在光标的第一位

    final Cursor allNonMediaFiles = managedQuery(uri, projection, selectionMimeType, selectionArgsPdf, sortOrder);

    int file_column_index = allNonMediaFiles.getColumnIndex(MediaStore.Files.FileColumns._ID);
    this.fileCount = allNonMediaFiles.getCount();
    this.pdf = new String[this.fileCount];
    this.pdfPath = new String[this.fileCount];

    for (int i = 0; i < this.fileCount; i++) {
        allNonMediaFiles.moveToFirst();
        pdfPath[i] = allNonMediaFiles.getString(1);
    }

如何获取此光标的列？

2 个答案: