Determining the size of an Android view at runtime

sqook_14302 0
Viewed 177436

I am trying to apply an animation to a view in my Android app after my activity is created. To do this, I need to determine the current size of the view, and then set up an animation to scale from the current size to the new size. This part must be done at runtime, since the view scales to different sizes depending on input from the user. My layout is defined in XML.

This seems like an easy task, and there are lots of SO questions regarding this though none which solved my problem, obviously. So perhaps I am missing something obvious. I get a handle to my view by:

ImageView myView = (ImageView) getWindow().findViewById(R.id.MyViewID);

This works fine, but when calling getWidth(), getHeight(), getMeasuredWidth(), getLayoutParams().width, etc., they all return 0. I have also tried manually calling measure() on the view followed by a call to getMeasuredWidth(), but that has no effect.

I have tried calling these methods and inspecting the object in the debugger in my activity's onCreate() and in onPostCreate(). How can I figure out the exact dimensions of this view at runtime?

android-view android
13 Answers

You can get both Position and Dimension of the view on screen

 val viewTreeObserver: ViewTreeObserver = videoView.viewTreeObserver;

if (viewTreeObserver.isAlive) {
    viewTreeObserver.addOnGlobalLayoutListener(object : ViewTreeObserver.OnGlobalLayoutListener {
        override fun onGlobalLayout() {
            //Remove Listener
            videoView.viewTreeObserver.removeOnGlobalLayoutListener(this);

            //View Dimentions
            viewWidth = videoView.width;
            viewHeight = videoView.height;

            //View Location
            val point = IntArray(2)
            videoView.post {
                videoView.getLocationOnScreen(point) // or getLocationInWindow(point)
                viewPositionX = point[0]
                viewPositionY = point[1]
            }

        }
    });
}
user_22521130

In Kotlin file, change accordingly

 Handler().postDelayed({

           Your Code

        }, 1)
user_140084070

If you need to know the dimensions of a View right after it is drawn you can simply call post() on that given View and send there a Runnable that executes whatever you need. It is a better solution than ViewTreeObserver and globalLayout since it gets called repeatedly not just once. This Runnsble will execute only once and you will know the views size.

user_84226580
Related