我有一个带有许多不同ViewHolders的RecyclerView适配器.其中一个ViewHolders包含一个 ImageView,它需要能够拍照,调整大小,然后显示它.对于模块化,我希望ViewHolder是自包含的：它不是父活动应该处理有关照片拍摄和显示过程的所有内容.文件路径也是常量(它永远不会改变).实际上,它是/storage/emulated/0/com.company.app/myst/cat.jpg.因此,这是我对ImageView的onClick方法的实现.

@Override
public void onClick(View v) {
    final FragmentManager fm = ((MyActivity) getContext()).getSupportFragmentManager();
    Fragment auxiliary = new Fragment() {
        @Override
        public void onActivityResult(int requestCode,int resultCode,Intent data) {
            resizeResaveAndDisplayPhoto();
            super.onActivityResult(requestCode,resultCode,data);
            fm.beginTransaction().remove(this).commit();
        }
    };
    fm.beginTransaction().add(auxiliary,"FRAGMENT_TAG").commit();
    fm.executePendingTransactions();

    Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
    if (null != takePictureIntent.resolveActivity(view.getContext().getPackageManager())) {
        ((MyActivity)view.getContext()).setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
        takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT,Uri.fromFile(photoFile));
         auxFragment.startActivityForResult(takePictureIntent,Constants.REQUEST_CODE_PHOTO);
    }
}

调用resizeResaveAndDisplayPhoto时,它会执行以下AsyncTask

public static class ResizeThenLoadImageTask extends AsyncTask<String,Void,Bitmap> {

    private final WeakReference<ImageView> imageViewWeakReference;
    private final WeakReference<File> fileWeakReference;
    private final WeakReference<Context> weakContext;
    private final int reqHeight;
    private final int reqWidth;

    public ResizeThenLoadImageTask(Context context,ImageView imageView,File file,int reqHeight,int reqWidth) {
        weakContext = new WeakReference<Context>(context);
        imageViewWeakReference = new WeakReference<>(imageView);
        fileWeakReference = new WeakReference(file);
        this.reqHeight = reqHeight;
        this.reqWidth = reqWidth;
    }

    @Override
    public Bitmap doInBackground(String... params) {
        File file = fileWeakReference.get();
        Bitmap bitmap = null;
        if (null != file) {
            bitmap = ImageUtils.reduceImageSize(file,reqHeight,reqWidth);
            ImageUtils.saveBitmapToGivenFile(bitmap,file);
        }
        return bitmap;
    }

    @Override
    public void onPostExecute(Bitmap bitmap) {
        if (null != imageViewWeakReference && null != fileWeakReference) {
            ImageView imageView = imageViewWeakReference.get();
            File file = fileWeakReference.get();
            if (null != imageView) {
                if (null != bitmap) {
                    imageView.setImageBitmap(bitmap);
                }
                else {
                    imageView.setImageResource(R.drawable.photo);
                }
                imageView.postDelayed(new Runnable() {
                    @Override
                    public void run() {
                        if (null != weakContext.get()) {
                            ((MyActivity) weakContext.get()).setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED);
                        }
                    }
                },10000);
            }
        }
    }
}

您可能会注意到我在拍照前锁定了方向,并在显示照片10秒后将其解锁.这个技巧是我的故障排除的一部分.所以情况就是这样.
上述系统工作得很好.在下列情况下会出现问题

>假设我已经在ImageView中有一张照片但想要替换它.
>所以我点击ImageView拍摄一张新照片.
>如果我旋转设备拍摄新照片,那么当我返回新照片时,会在旧照片返回之前短暂显示.
>所以我锁定方向,看看发生了什么.这是我发现的.
>只要我锁定方向,新照片就会显示.一旦方向解锁(10秒),旧照片就会返回.
>如果我离开活动和返回,旧照片仍在显示.
>如果我完全关闭应用程序然后返回,那么我会看到新照片.