Changing the imageView object in android after loading the activity

Question

I am making an application in Android, which requires sending bitmap object from one activity and displaying that bitmap object sent on the second activity page. But , I am getting a blank screen

Here is a sample of my code for sending the Bitmap object :-

Intent intent = new Intent(Display2.this, Display3.class);
ImageView iv = (ImageView) findViewById(R.id.imageView1);
Bitmap bitmap = Bitmap.createBitmap(iv.getWidth(), iv.getHeight(), Bitmap.Config.RGB_565);
intent.putExtra("BitmapImage", bitmap);
startActivity(intent);

Now the part of code on second activity to retrieve the sent object and displaying it on screen :-

public class Display3 extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        Bitmap bitmap = (Bitmap)getIntent().getParcelableExtra("BitmapImage");
        ImageView myIV = (ImageView) findViewById(R.id.imageView1);
        bitmap = bitmap.createBitmap(myIV.getWidth(), myIV.getHeight(), Bitmap.Config.RGB_565);
        myIV.setImageBitmap(bitmap);
        setContentView(R.layout.display3);

    }
}

can anyone suggest whats wrong in this part ?

Thanks !

score 2 · Accepted Answer · answered Apr 03 '12 at 04:54

2

Bitmap implements Parcelable object, so you could always pass it in the intent like below :

Intent intent = new Intent(this, NewActivity.class);
intent.putExtra("BitmapImage", bitmap);

and retrieve it on the other end:

Bitmap bitmap = (Bitmap) intent.getParcelableExtra("BitmapImage");

answered Apr 03 '12 at 04:54

Maulik J

2,745
19
22

But making the suggested changes displays an error in the code – Prashant Singh Apr 03 '12 at 05:00
check weather the bitmap is made successfully to bitmap-object or not – Maulik J Apr 03 '12 at 05:04

score 2 · Answer 2 · edited May 23 '17 at 12:04

this is not good for passing bitmap from one activity to another..

You can simply name you Bitmap as static first. then create a method like

public static Bitmap getBitmap(){
    return bitmap;
}

then you can simply call from other activities,

bitmapexistingclass.getBitmap();

if we use intents for passing bitmap we will get some errors check this question How to pass bitmap from one activity to another

score 1 · Answer 3 · answered Apr 03 '12 at 05:00

1

from your code above you are creating an empty bitmap:

ImageView iv = (ImageView) findViewById(R.id.imageView1);
Bitmap bitmap = Bitmap.createBitmap(iv.getWidth(), iv.getHeight(), Bitmap.Config.RGB_565);

I do not see any reason why from this code you'll get anything else then blank black bitmap with hight and width equals to the imageView hight and width

answered Apr 03 '12 at 05:00

Tal Kanel

10,475
10
60
98

After doing the changes, it says unable to start activity :( – Prashant Singh Apr 03 '12 at 05:08
well, that's another story :) but if you'll write the code that you changed, and atach the stack trace log - maybe I could help with that – Tal Kanel Apr 03 '12 at 05:40

score 0 · Answer 4 · answered Apr 03 '12 at 05:05

what you are expecting from android to fill drawing in Bitmap itself , you are creating an Empty Bitmap Object with height and width equavalent to ImageView object; as Bitmap implements Parcelable you can simply put it in bundle and retrive on other Activity

score 0 · Answer 5 · answered Apr 03 '12 at 05:13

Use below two methods to convert a bitmap to string and vice versa. Then you can pass the string with intents from activity to another activity. I too do the same in my application. Then we dont need to use ParcelableExtra and serialzable class.

public String convertBitmapToString(Bitmap src) {
if(src!= null){
ByteArrayOutputStream os=new ByteArrayOutputStream();
src.compress(android.graphics.Bitmap.CompressFormat.PNG, 100,(OutputStream) os);
byte[] byteArray = os.toByteArray();
return Base64.encodeToString(byteArray,Base64.DEFAULT);  
}
return null;            
}

public Bitmap getBitMapFromString(String src){
Bitmap bitmap = null;
if(src!= null){
byte[] decodedString = Base64.decode(src.getBytes(), Base64.DEFAULT);
bitmap = BitmapFactory.decodeByteArray(decodedString,0,decodedString.length);
return bitmap;
}
return null;
}

Changing the imageView object in android after loading the activity

5 Answers5