android - save image into gallery

问题:

i have an app with a gallery of images and i want that the user can save it into his own gallery. I've created an option menu with a single voice "save" to allow that but the problem is...how can i save the image into the gallery?

this is my code:

@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);
            }
        }

i'm not sure of this part of code:

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

is it correct to save into the gallery? unfortunately the code doesn't work :(

回答1:

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

The former code will add the image at the end of the gallery. If you want to modify the date so it appears at the beginning or any other metadata, see the code below (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;
        }
    }
}

回答2:

Actually, you can save you picture at any place. If you want to save in a public space, so any other application can access, use this code:

storageDir = new File(
    Environment.getExternalStoragePublicDirectory(
        Environment.DIRECTORY_PICTURES
    ), 
    getAlbumName()
);

The picture doesn't go to the album. To do this, you need to call a scan:

private void galleryAddPic() {
    Intent mediaScanIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
    File f = new File(mCurrentPhotoPath);
    Uri contentUri = Uri.fromFile(f);
    mediaScanIntent.setData(contentUri);
    this.sendBroadcast(mediaScanIntent);
}

You can found more info at https://developer.android.com/training/camera/photobasics.html#TaskGallery

回答3:

I've tried a lot of things to let this work on Marshmallow and Lollipop. Finally i ended up moving the saved picture to the DCIM folder (new Google Photo app scan images only if they are inside this folder apparently)

public static File createImageFile() throws IOException {
    // Create an image file name
    String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss")
         .format(System.currentTimeInMillis());
    File storageDir = new File(Environment
         .getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM) + "/Camera/");
    if (!storageDir.exists())
        storageDir.mkdirs();
    File image = File.createTempFile(
            timeStamp,                   /* prefix */
            ".jpeg",                     /* suffix */
            storageDir                   /* directory */
    );
    return image;
}

And then the standard code for scanning files which you can find in the Google Developers site too.

public static void addPicToGallery(Context context, String photoPath) {
    Intent mediaScanIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
    File f = new File(photoPath);
    Uri contentUri = Uri.fromFile(f);
    mediaScanIntent.setData(contentUri);
    context.sendBroadcast(mediaScanIntent);
}

Please remember that this folder could not be present in every device in the world and that starting from Marshmallow (API 23), you need to request the permission to WRITE_EXTERNAL_STORAGE to the user.

回答4:

According to this course, the correct way to do this is:

Environment.getExternalStoragePublicDirectory(
        Environment.DIRECTORY_PICTURES
    )

This will give you the root path for the gallery directory.

回答5:

private void galleryAddPic() {
    Intent mediaScanIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
    File f = new File(mCurrentPhotoPath);
    Uri contentUri = Uri.fromFile(f);
    mediaScanIntent.setData(contentUri);
    this.sendBroadcast(mediaScanIntent);
}

回答6:

You can create a directory inside the camera folder and save. And scan once you complete. It will instantly show your image in the gallery. Cheers!!

            String root = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM).toString()+ "/Camera/Your_Directory_Name";
            File myDir = new File(root);
            myDir.mkdirs();
            String fname = "Image-" + image_name + ".png";
            File file = new File(myDir, fname);
            System.out.println(file.getAbsolutePath());
            if (file.exists()) file.delete();
            Log.i("LOAD", root + fname);
            try {
                FileOutputStream out = new FileOutputStream(file);
                finalBitmap.compress(Bitmap.CompressFormat.PNG, 90, out);
                out.flush();
                out.close();
            } catch (Exception e) {
                e.printStackTrace();
            }

            MediaScannerConnection.scanFile(context, new String[]{file.getPath()}, new String[]{"image/jpeg"}, null);

回答7:

I come here with the same doubt but for Xamarin for Android, I have used the Sigrist answer to do this method after save my file:

private void UpdateGallery()
{
    Intent mediaScanIntent = new Intent(Intent.ActionMediaScannerScanFile);
    Java.IO.File file = new Java.IO.File(_path);
    Android.Net.Uri contentUri = Android.Net.Uri.FromFile(file);
    mediaScanIntent.SetData(contentUri);
    Application.Context.SendBroadcast(mediaScanIntent);
} 

and it solved my problem, Thx Sigrist. I put it here becouse i did not found an answare about this for Xamarin and i hope it can help other people.

回答8:

In my case the solutions above did not work I had to do the following:

sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, Uri.fromFile(f)));

回答9:

 String filePath="/storage/emulated/0/DCIM"+app_name;
    File dir=new File(filePath);
    if(!dir.exists()){
        dir.mkdir();
    }

This code is in onCreate method.This code is for creating a directory of app_name. Now,this directory can be accessed using default file manager app in android. Use this string filePath wherever required to set your destination folder. I am sure this method works on Android 7 too because I tested on it.Hence,it can work on other versions of android too.