如何让图片在相册中展示 (将图片保存到系统相册中)

一. 系统相册的数源其实来自系统媒体库, 即android.provider.MediaStore. 既然如此, 只需要将图片数据插入到系统媒体库就行啦 !

二. 系统图库相关API

MediaStore.Images.Media.insertImage()  //将图信息片插入到系统相册中
MediaStore.Images.Media.query()            //查询系统相册
MediaStore.Images.Media.getBitmap()     //从系统相册中获取图片

利用MediaStore.Images.Media.insertImage()方法把图片数据插入到系统相册中, 上代码:

下载网络图片, 并保存到系统相册中 AlbumManager.java

public class AlbumManager {

    /**
     * 下载图片
     * @param imageUrl
     * @param downloadCallback
     */
    public static void download(final String imageUrl, final DownloadCallback downloadCallback) {
        Flowable.create(new FlowableOnSubscribe<Boolean>() {
            @Override
            public void subscribe(FlowableEmitter<Boolean> e) throws Exception {
                OkHttpClient client = new OkHttpClient();
                Request request = new Request.Builder().url(imageUrl).build();
                Call call = client.newCall(request);
                Response response = call.execute();

                if(response != null && response.body() != null) {
                    BufferedSink sink = null;
                    try {
                        sink = Okio.buffer(Okio.sink(FileUtils.createFileFrom(imageUrl)));
                        sink.write(response.body().bytes());
                        e.onNext(true);
                    } catch (Exception exception) {
                        Log.e("_stone_", "AlbumManager-download-subscribe(): " + exception.getMessage());
                        e.onNext(false);
                    } finally {
                        if(sink != null) sink.close();
                    }
                } else {
                    e.onNext(false);
                }
            }
        }, BackpressureStrategy.BUFFER)
                .subscribeOn(Schedulers.io())
                .observeOn(AndroidSchedulers.mainThread())
                .subscribe(new Consumer<Boolean>() {
                    @Override
                    public void accept(@NonNull Boolean result) throws Exception {
                        //将下载的图片插入到系统相册, 并同步刷新系统相册(更新UI)
                        if(result) insertSystemAlbumAndRefresh(imageUrl);

                        //回调更新UI
                        if(downloadCallback != null) downloadCallback.onDownloadCompleted(result);
                    }
                }, new Consumer<Throwable>() {
                    @Override
                    public void accept(@NonNull Throwable throwable) throws Exception {
                        Log.d("_stone_", "AlbumManager-download-OnError-accept: " + throwable.getMessage());
                        if(downloadCallback != null) downloadCallback.onDownloadCompleted(false);
                    }
                });
    }

    /**
     * 插入到系统相册, 并刷新系统相册
     * @param imageUrl
     */
    private static void insertSystemAlbumAndRefresh(final String imageUrl) {
        Flowable.create(new FlowableOnSubscribe<Object>() {
            @Override
            public void subscribe(FlowableEmitter<Object> e) throws Exception {
                File file = FileUtils.createFileFrom(imageUrl);
                String imageUri = MediaStore.Images.Media.insertImage(ApplicationProvider.IMPL.getApp().getContentResolver(), file.getAbsolutePath(), file.getName(), "图片: " + file.getName());
                Log.d("_stone_", "insertSystemAlbumAndRefresh-subscribe: imageUri=" + imageUri);
                syncAlbum(imageUrl);
            }
        }, BackpressureStrategy.BUFFER)
                .subscribeOn(Schedulers.io())
                .observeOn(AndroidSchedulers.mainThread())
                .subscribe();
    }

    /**
     * 同步刷新系统相册
     * @param imageUrl
     */
    private static void syncAlbum(String imageUrl) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
            final Intent scanIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
            final Uri contentUri = Uri.fromFile(FileUtils.createFileFrom(imageUrl).getAbsoluteFile());
            scanIntent.setData(contentUri);
            ApplicationProvider.IMPL.getApp().sendBroadcast(scanIntent);
        } else {
            //4.4开始不允许发送"Intent.ACTION_MEDIA_MOUNTED"广播, 否则会出现: Permission Denial: not allowed to send broadcast android.intent.action.MEDIA_MOUNTED from pid=15410, uid=10135
            final Intent intent = new Intent(Intent.ACTION_MEDIA_MOUNTED, Uri.parse("file://" + Environment.getExternalStorageDirectory()));
            ApplicationProvider.IMPL.getApp().sendBroadcast(intent);
        }
    }
}

调用MediaStore.Images.Media.insertImage()方法保持图片信息到系统相册后, 打开系统相册APP就可以看到刚才保存的图片了; 为了保险起见, 可以同步一下系统相册, 即下面这段代码:

private static void syncAlbum(String imageUrl) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
            final Intent scanIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
            final Uri contentUri = Uri.fromFile(FileUtils.createFileFrom(imageUrl).getAbsoluteFile());
            scanIntent.setData(contentUri);
            ApplicationProvider.IMPL.getApp().sendBroadcast(scanIntent);
        } else {
            //4.4开始不允许发送"Intent.ACTION_MEDIA_MOUNTED"广播, 否则会出现: Permission Denial: not allowed to send broadcast android.intent.action.MEDIA_MOUNTED from pid=15410, uid=10135
            final Intent intent = new Intent(Intent.ACTION_MEDIA_MOUNTED, Uri.parse("file://" + Environment.getExternalStorageDirectory()));
            ApplicationProvider.IMPL.getApp().sendBroadcast(intent);
        }
    }
}

代码已经上传到GitHub SaveImage2SystemAlbum, 如有不妥之处, 欢迎指正 !

@@@@@@@@@@@@@@@@@@@@@@@@@

更新(2017-04-07)

如果你调用系统相机拍摄视频, 而不把视频加入到媒体库中, 视频同样也是不会在系统相册中展示的. 因此拍摄完视频后需要将拍摄的视频加入到系统媒体库中.
调用系统相机拍摄视频 并 将拍摄的视频加入到系统媒体库中 (这样就可以在系统相册中看到你拍摄的视频啦):

//调用系统相机拍摄视频
private void captureVideo() {
        // 激活系统的照相机进行录像
        Intent intent = new Intent();
        intent.setAction("android.media.action.VIDEO_CAPTURE");
        intent.addCategory("android.intent.category.DEFAULT");

        // 保存录像到指定的路径
        videoFile = new File(videoFileName + ".3gp");
        if (Build.VERSION.SDK_INT >= 24) { //判断版本是否在7.0以上
            mUri = FileProvider.getUriForFile(this, getApplicationContext().getPackageName() + ".provider", videoFile);
            intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
        } else {
            mUri = Uri.fromFile(videoFile);
        }
        intent.putExtra(MediaStore.EXTRA_OUTPUT, mUri);
        startActivityForResult(intent, REQUEST_CAMERA);
    }
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == REQUEST_CAMERA && resultCode == RESULT_OK) {
        addVideo2MediaStore(videoFile);
    }
}

//将视频加入到系统媒体库中
private void addVideo2MediaStore(File videoFile) {
    //此处需要rxjava2的支持
    Flowable.create(new FlowableOnSubscribe<Boolean>() {
        @Override
        public void subscribe(FlowableEmitter<Boolean> e) throws Exception {
            try {
                // 将视频加入到媒体库
                ContentValues contentValues = new ContentValues();
                contentValues.put(MediaStore.Video.Media.DATA, videoFile.getAbsolutePath());
                contentValues.put(MediaStore.Video.Media.TITLE, videoFile.getName());
                contentValues.put(MediaStore.Video.Media.DISPLAY_NAME, videoFile.getName());
                Uri uri = getContentResolver().insert(MediaStore.Video.Media.EXTERNAL_CONTENT_URI, contentValues);
                DevUtil.dd("video uri: " + uri.toString());
                e.onNext(true);
                e.onComplete();
            } catch(Exception exception) {
                e.onNext(false);
                e.onComplete();
            }
        }
    }, BackpressureStrategy.BUFFER)
    .subscribeOn(Schedulers.io())
    .observeOn(AndroidSchedulers.mainThread())
    .subscribe(new Consumer<Boolean>() {
        @Override
        public void accept(Boolean result) throws Exception {
            DevUtil.dd("addVideo2MediaStore() : " + (result ? "插入成功!" : "插入失败!") );
        }
    }, new Consumer<Throwable>() {
        @Override
        public void accept(Throwable throwable) throws Exception {
            DevUtil.dd("addVideo2MediaStore() : " + "插入失败!");
        }
    });
}