android - 获取主存储和二级存储上 DCIM 文件夹的路径

Question

我正在编写一个应用程序，它应该上传存储在内存和 SD 卡上的 DCIM/Camera 文件夹中的相机拍摄的照片。

这意味着在每次上传之前，必须检查所有可用存储空间是否存在任何图像。

我使用 Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM) 访问主存储，它可以是 SD 卡或内存(取决于设备)。

来自文档:

Note: don't be confused by the word "external" here. This directory can better be thought as media/shared storage. It is a filesystem that can hold a relatively large amount of data and that is shared across all applications (does not enforce permissions). Traditionally this is an SD card, but it may also be implemented as built-in storage in a device that is distinct from the protected internal storage and can be mounted as a filesystem on a computer.

我的问题是，如何在不对路径进行硬编码的情况下访问辅助存储来检查 DCIM/Camera 文件夹中是否存在图像，这不能很好地工作，因为 SD 卡可能会在不同的路径中被模拟。

Answer 1

尝试使用此代码选择上次使用的 DCIM/Camera 文件夹。

String getDCIMCamera() {
    try {
        String[] projection = new String[]{
                MediaStore.Images.ImageColumns._ID,
                MediaStore.Images.ImageColumns.DATA,
                MediaStore.Images.ImageColumns.BUCKET_DISPLAY_NAME,
                MediaStore.Images.ImageColumns.DATE_TAKEN,
                MediaStore.Images.ImageColumns.MIME_TYPE};

        Cursor cursor = getContentResolver().query(
                MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
                projection,
                null,
                null,
                MediaStore.Images.ImageColumns.DATE_TAKEN + " DESC");
        if (cursor != null) {
            cursor.moveToFirst();
            do {
                String path = cursor.getString(cursor.getColumnIndex(MediaStore.Images.Media.DATA));
                if (path.contains("/DCIM/")) {
                    File file = new File(path);
                    path = file.getParent();
                    cursor.close();
                    return path;
                }
            } while (cursor.moveToNext());
            cursor.close();
        }
    }
    catch (Exception e) {
    }
    return "";
}

另见@Pedram 提示:https://stackoverflow.com/a/24189813/966789