Where in the lifecycle of my Android app should I get width and height of image view?

Question

private void getPicDetails() {

            targetW = img_cow.getWidth();
            targetH = img_cow.getHeight();

            Log.e("targetW: ", "" + targetW);
            Log.e("targetH: ", "" + targetH); 
        }

I have an image view and the method above gets the height and width to print the values of height and width. Now when I call getPicDetails() in onCreate, the values are 0, same as when I put it in OnStart and onResume.

My question is: where should I put my method such that the imageview is initialized and exists?

Could you please post the code which instantiates img_cow, assuming it is ImageView — stack_ved, Nov 28 '13 at 08:58
possible duplicate of [Android get width returns 0](http://stackoverflow.com/questions/3591784/android-get-width-returns-0) — Steve Benett, Nov 28 '13 at 09:03

score 2 · Accepted Answer · answered Nov 28 '13 at 08:58

2

you can call inside the onWindowFocusChanged

@Override
public void onWindowFocusChanged(boolean hasFocus){
    int width=imageView.getWidth();
    int height=imageView.getHeight();
}

answered Nov 28 '13 at 08:58

Aerrow

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what if you need to use it in a fragment? – android developer Dec 24 '13 at 09:58

Caner · Answer 2 · 2013-11-28T09:12:59.720

0

where in the lifecycle of my android app should i get width and height of image view

After layout is complete:

@Override
public void onLayout(boolean changed, int left, int top, int right, int bottom) {
    super.onLayout(changed, left, top, right, bottom);
    getPicDetails();
}

edited Nov 28 '13 at 09:12

answered Nov 28 '13 at 09:00

Caner

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eclipse says remove @Override, as if onLayout is not a method of Activity – Operative Nov 28 '13 at 10:19
how do you create your images? – Caner Nov 28 '13 at 10:32
call camera using photointent and then convert it into bitmap which i have to scale to size of the imageview (which is the reason i'm asking where to call `getPicDetails()`). then stick the bitmap into imageview, you want the code? – Operative Nov 28 '13 at 11:21
call it after you inflate your layout – Caner Nov 28 '13 at 11:28
`onLayout` is a method from the View class, not Activity – gatti Apr 14 '16 at 08:47

android developer · Answer 3 · 2018-07-10T10:05:31.833

you can use the next function i've made:

  public static void runJustBeforeBeingDrawn(View view, Runnable runnable)
  {
    ViewTreeObserver.OnPreDrawListener preDrawListener = new ViewTreeObserver.OnPreDrawListener(view, runnable)
    {
      public boolean onPreDraw() {
        ViewUtil.this.getViewTreeObserver().removeOnPreDrawListener(this);
        runnable.run();
        return true;
      }
    };
    view.getViewTreeObserver().addOnPreDrawListener(preDrawListener);
  }

EDIT: Alternative to runJustBeforeBeingDrawn: https://stackoverflow.com/a/28136027/878126

Where in the lifecycle of my Android app should I get width and height of image view?

3 Answers3