Attempt to invoke virtual method 'void android.graphics.Bitmap.copyPixelsFromBuffer(java.nio.Buffer)' on a null object reference

Question

I have a ImageView I am getting bitmap out of that, and then use copyPixelstoBuffer and I am copying it to buffer_temp, now I want to use reverse algorithm to again convert it to another bitmap and from that bitmap to ImageView2,

what exactly I am doing is Copying an Image in ImageView using Buffer and Pasting it onto another Imageview using Buffer, but while Copying copyPixelsFromBuffer always throw

java.lang.NullPointerException: Attempt to invoke virtual method 'void android.graphics.Bitmap.copyPixelsFromBuffer(java.nio.Buffer)' on a null object reference.

Dont know why, Need help,

try {
                Buffer bfr = null;
                iv1.setImageResource(R.drawable.olx);
                BitmapDrawable drawable = (BitmapDrawable) iv1.getDrawable();
                Bitmap bitmap = drawable.getBitmap();
                int bytes=bitmap.getByteCount();
                ByteBuffer buffer_temp= ByteBuffer.allocate(bytes);
                bitmap.copyPixelsToBuffer(buffer_temp);
                System.out.println("Values are "+ bitmap.getAllocationByteCount());

                Bitmap btmp=null;

                //btmp.copyPixelsFromBuffer(buffer_temp);


                if(buffer_temp==null)
                 return;

                buffer_temp.rewind();

                btmp.copyPixelsFromBuffer(buffer_temp);


                if(buffer_temp==null)
                {
                    Toast.makeText(getApplicationContext(), "Null", Toast.LENGTH_SHORT).show();
                }
                else
                {
                    Toast.makeText(getApplicationContext(), "Not Null", Toast.LENGTH_SHORT).show();
                }



            } catch (NotFoundException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

use a debugger and check the contents of your buffer_temp after buffer_temp.rewind() this error is only possible when either buffer_temp is null or btmp is — Aditya Chauhan
– Aditya Chauhan, Commented Aug 1, 2015 at 19:40

erginduran · Accepted Answer · 2016-10-04 15:29:50Z

2

btmp is null. There is no way that by using the attached code.Then, the value of btmp would be anything. But it's null!

If you want to clone Bitmap the use create method or any other of that sort.

Bitmap btmp = Bitmap.create(drawable.getBitmap());

edited Oct 4, 2016 at 15:29

erginduran

1,6925 gold badges29 silver badges53 bronze badges

answered Aug 1, 2015 at 19:40

EE66

4,6611 gold badge19 silver badges20 bronze badges

Sign up to request clarification or add additional context in comments.

6 Comments

Alexander Zaldostanov Over a year ago

yes, btmp is null, because I want a new bitmap into ImageView2

EE66 Over a year ago

Paste way more code. You have serious issue back there.

Alexander Zaldostanov Over a year ago

so what should I do, because I want to use new Bitmap object

Alexander Zaldostanov Over a year ago

its the same exception which I have described, you can go ahead and do that, take two ImageView and one button, and try the above code snippet, it keeps crashing

EE66 Over a year ago

If the code above throws then you dont have any Bitmap at the first place

|

ankhzet · Accepted Answer · 2015-08-01 20:32:07Z

2

"yes, btmp is null"

But, you trying to invoke method call on it:

btmp.copyPixelsFromBuffer(buffer_temp); // <- here

That not going to work. You should initialize btmp before using it.

Update:

Init it like this:

...
System.out.println("Values are "+ bitmap.getAllocationByteCount());

// here's the initialization
Bitmap btmp = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), bitmap.getConfig());

buffer_temp.rewind();

// now you can call copyPixelsFromBuffer() on btmp
btmp.copyPixelsFromBuffer(buffer_temp);
...

edited Aug 1, 2015 at 20:32

answered Aug 1, 2015 at 19:52

ankhzet

2,5991 gold badge27 silver badges36 bronze badges

Collectives™ on Stack Overflow

Attempt to invoke virtual method 'void android.graphics.Bitmap.copyPixelsFromBuffer(java.nio.Buffer)' on a null object reference

2 Answers 2

6 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

6 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related