Android:如何查询存储桶名称列表

Question

我想只检索存储桶的名称(相册).例如相机,下载等,但不是所有照片中的相机,下载等列表,那么如何为每个存储桶名称检索一行？

我的意思是在Gallery Application中,你首先有专辑,例如Camera.当您单击它时,它会显示相机的所有照片.

我可以使用查询的Where子句查询Camera Roll中的照片.但是,如果我只想要每个专辑名称的名称而不是照片,那么可以查询吗？如果我查询所有照片并且每组照片只拍一行,那么这将非常耗时.

请帮忙

Answer 1

我有同样的问题,这是我的解决方案(跟踪图库源代码后)获取专辑名称和其中的第一个图像(可以用作此专辑的缩略图):

(注意,通过groupby和order技术删除了bucket重复)

    // which image properties are we querying
    String[] PROJECTION_BUCKET = {
            ImageColumns.BUCKET_ID,
            ImageColumns.BUCKET_DISPLAY_NAME,
            ImageColumns.DATE_TAKEN,
            ImageColumns.DATA};
    // We want to order the albums by reverse chronological order. We abuse the
    // "WHERE" parameter to insert a "GROUP BY" clause into the SQL statement.
    // The template for "WHERE" parameter is like:
    //    SELECT ... FROM ... WHERE (%s)
    // and we make it look like:
    //    SELECT ... FROM ... WHERE (1) GROUP BY 1,(2)
    // The "(1)" means true. The "1,(2)" means the first two columns specified
    // after SELECT. Note that because there is a ")" in the template, we use
    // "(2" to match it.
    String BUCKET_GROUP_BY =
            "1) GROUP BY 1,(2";
    String BUCKET_ORDER_BY = "MAX(datetaken) DESC";

    // Get the base URI for the People table in the Contacts content provider.
    Uri images = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;

    Cursor cur = getContentResolver().query(
            images, PROJECTION_BUCKET, BUCKET_GROUP_BY, null, BUCKET_ORDER_BY);

    Log.i("ListingImages"," query count=" + cur.getCount());

    if (cur.moveToFirst()) {
        String bucket;
        String date;
        String data;
        int bucketColumn = cur.getColumnIndex(
                MediaStore.Images.Media.BUCKET_DISPLAY_NAME);

        int dateColumn = cur.getColumnIndex(
                MediaStore.Images.Media.DATE_TAKEN);
        int dataColumn = cur.getColumnIndex(
                MediaStore.Images.Media.DATA);

        do {
            // Get the field values
            bucket = cur.getString(bucketColumn);
            date = cur.getString(dateColumn);
            data = cur.getString(dataColumn);

            // Do something with the values.
            Log.i("ListingImages", " bucket=" + bucket 
                    + "  date_taken=" + date
                    + "  _data=" + data);
        } while (cur.moveToNext());
    }

Answer 2

这里是.这个对我有用:

Uri images = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
    String[] projection = new String[]{   
            MediaStore.Images.Media.BUCKET_ID,
            MediaStore.Images.Media.BUCKET_DISPLAY_NAME,
            MediaStore.Images.Media.DATE_TAKEN,
            MediaStore.Images.Media.DATA
    };

    String BUCKET_ORDER_BY = MediaStore.Images.Media.DATE_MODIFIED + " DESC";
    String BUCKET_GROUP_BY = "1) GROUP BY 1,(2";
    Cursor imagecursor = managedQuery(images,
            projection, // Which columns to return
            BUCKET_GROUP_BY,       // Which rows to return (all rows)
            null,       // Selection arguments (none)
            BUCKET_ORDER_BY        // Ordering
            );

    this.imageUrls = new ArrayList<String>();
    this.imageBuckets  = new ArrayList<String>();
    for (int i = 0; i < imagecursor.getCount(); i++)
    {
        imagecursor.moveToPosition(i);
        int bucketColumnIndex = imagecursor.getColumnIndex(MediaStore.Images.Media.BUCKET_DISPLAY_NAME);
        String bucketDisplayName = imagecursor.getString(bucketColumnIndex);
        imageBuckets.add(bucketDisplayName);
        int dataColumnIndex = imagecursor.getColumnIndex(MediaStore.Images.Media.DATA);
        imageUrls.add(imagecursor.getString(dataColumnIndex));

    }

imageBuckets Arraylist包含专辑名称

imageUrls Arraylist包含相册的最后修改图像的路径,您可以将其用作缩略图

Answer 3

您可以查询 MediaStore.Images.Media.BUCKET_DISPLAY_NAME 来获取它。Peter Knego举了一个很好的例子。这是一个很好的示例，您可以使用 ContentResolver 对象中的 query() 来更新它，而不是使用已弃用的 ManagedQuery() 。

// which image properties are we querying
String[] projection = new String[]{
        MediaStore.Images.Media._ID,
        MediaStore.Images.Media.BUCKET_DISPLAY_NAME,
        MediaStore.Images.Media.DATE_TAKEN
};

// Get the base URI for the People table in the Contacts content provider.
Uri images = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;

// Make the query.
ContentResolver cr = getContentResolver();
Cursor cur = cr.query(images,
        projection, // Which columns to return
        "",         // Which rows to return (all rows)
        null,       // Selection arguments (none)
        ""          // Ordering
        );

Log.i("ListingImages"," query count="+cur.getCount());

if (cur.moveToFirst()) {
    String bucket;
    String date;
    int bucketColumn = cur.getColumnIndex(
        MediaStore.Images.Media.BUCKET_DISPLAY_NAME);

    int dateColumn = cur.getColumnIndex(
        MediaStore.Images.Media.DATE_TAKEN);

    do {
        // Get the field values
        bucket = cur.getString(bucketColumn);
        date = cur.getString(dateColumn);

        // Do something with the values.
        Log.i("ListingImages", " bucket=" + bucket 
               + "  date_taken=" + date);
    } while (cur.moveToNext());

}