java - android - 将图像保存到画廊

Question

我有一个带有图片库的应用程序，我希望用户可以将其保存到自己的图库中。我创建了一个带有单个语音“保存”的选项菜单以允许这样做，但问题是...如何将图像保存到图库中？

这是我的代码:

@Override
        public boolean onOptionsItemSelected(MenuItem item) {
            // Handle item selection
            switch (item.getItemId()) {
            case R.id.menuFinale:

                imgView.setDrawingCacheEnabled(true);
                Bitmap bitmap = imgView.getDrawingCache();
                File root = Environment.getExternalStorageDirectory();
                File file = new File(root.getAbsolutePath()+"/DCIM/Camera/img.jpg");
                try 
                {
                    file.createNewFile();
                    FileOutputStream ostream = new FileOutputStream(file);
                    bitmap.compress(CompressFormat.JPEG, 100, ostream);
                    ostream.close();
                } 
                catch (Exception e) 
                {
                    e.printStackTrace();
                }



                return true;
            default:
                return super.onOptionsItemSelected(item);
            }
        }

我不确定这部分代码:

File root = Environment.getExternalStorageDirectory();
                File file = new File(root.getAbsolutePath()+"/DCIM/Camera/img.jpg");

保存到图库是否正确？不幸的是，代码不起作用:(

Answer 1

MediaStore.Images.Media.insertImage(getContentResolver(), yourBitmap, yourTitle , yourDescription);

之前的代码会将图片添加到图库末尾。如果您想修改日期以使其出现在开头或任何其他元数据中，请参见下面的代码(Cortesy of S-K，samkirton):

https://gist.github.com/samkirton/0242ba81d7ca00b475b9

/**
 * Android internals have been modified to store images in the media folder with 
 * the correct date meta data
 * @author samuelkirton
 */
public class CapturePhotoUtils {

    /**
     * A copy of the Android internals  insertImage method, this method populates the 
     * meta data with DATE_ADDED and DATE_TAKEN. This fixes a common problem where media 
     * that is inserted manually gets saved at the end of the gallery (because date is not populated).
     * @see android.provider.MediaStore.Images.Media#insertImage(ContentResolver, Bitmap, String, String)
     */
    public static final String insertImage(ContentResolver cr, 
            Bitmap source, 
            String title, 
            String description) {

        ContentValues values = new ContentValues();
        values.put(Images.Media.TITLE, title);
        values.put(Images.Media.DISPLAY_NAME, title);
        values.put(Images.Media.DESCRIPTION, description);
        values.put(Images.Media.MIME_TYPE, "image/jpeg");
        // Add the date meta data to ensure the image is added at the front of the gallery
        values.put(Images.Media.DATE_ADDED, System.currentTimeMillis());
        values.put(Images.Media.DATE_TAKEN, System.currentTimeMillis());

        Uri url = null;
        String stringUrl = null;    /* value to be returned */

        try {
            url = cr.insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values);

            if (source != null) {
                OutputStream imageOut = cr.openOutputStream(url);
                try {
                    source.compress(Bitmap.CompressFormat.JPEG, 50, imageOut);
                } finally {
                    imageOut.close();
                }

                long id = ContentUris.parseId(url);
                // Wait until MINI_KIND thumbnail is generated.
                Bitmap miniThumb = Images.Thumbnails.getThumbnail(cr, id, Images.Thumbnails.MINI_KIND, null);
                // This is for backward compatibility.
                storeThumbnail(cr, miniThumb, id, 50F, 50F,Images.Thumbnails.MICRO_KIND);
            } else {
                cr.delete(url, null, null);
                url = null;
            }
        } catch (Exception e) {
            if (url != null) {
                cr.delete(url, null, null);
                url = null;
            }
        }

        if (url != null) {
            stringUrl = url.toString();
        }

        return stringUrl;
    }

    /**
     * A copy of the Android internals StoreThumbnail method, it used with the insertImage to
     * populate the android.provider.MediaStore.Images.Media#insertImage with all the correct
     * meta data. The StoreThumbnail method is private so it must be duplicated here.
     * @see android.provider.MediaStore.Images.Media (StoreThumbnail private method)
     */
    private static final Bitmap storeThumbnail(
            ContentResolver cr,
            Bitmap source,
            long id,
            float width, 
            float height,
            int kind) {

        // create the matrix to scale it
        Matrix matrix = new Matrix();

        float scaleX = width / source.getWidth();
        float scaleY = height / source.getHeight();

        matrix.setScale(scaleX, scaleY);

        Bitmap thumb = Bitmap.createBitmap(source, 0, 0,
            source.getWidth(),
            source.getHeight(), matrix,
            true
        );

        ContentValues values = new ContentValues(4);
        values.put(Images.Thumbnails.KIND,kind);
        values.put(Images.Thumbnails.IMAGE_ID,(int)id);
        values.put(Images.Thumbnails.HEIGHT,thumb.getHeight());
        values.put(Images.Thumbnails.WIDTH,thumb.getWidth());

        Uri url = cr.insert(Images.Thumbnails.EXTERNAL_CONTENT_URI, values);

        try {
            OutputStream thumbOut = cr.openOutputStream(url);
            thumb.compress(Bitmap.CompressFormat.JPEG, 100, thumbOut);
            thumbOut.close();
            return thumb;
        } catch (FileNotFoundException ex) {
            return null;
        } catch (IOException ex) {
            return null;
        }
    }
}