The code is simple:
<ImageView android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:src="@drawable/cat"/>
Notice the ImageView used fill_parent for width and height.
The image cat is a small image and it will be zoomed in to fit the ImageView, and keep the width/height ratio at the same time.
My question is how to get the displayed size of the image? I tried:
imageView.getDrawable().getIntrinsicHeight()
But which it the original height of the image cat.
I tried:
imageView.getDrawable().getBounds()
But which returns Rect(0,0,0,0).
the following will work:
ih=imageView.getMeasuredHeight();//height of imageView
iw=imageView.getMeasuredWidth();//width of imageView
iH=imageView.getDrawable().getIntrinsicHeight();//original height of underlying image
iW=imageView.getDrawable().getIntrinsicWidth();//original width of underlying image
if (ih/iH<=iw/iW) iw=iW*ih/iH;//rescaled width of image within ImageView
else ih= iH*iw/iW;//rescaled height of image within ImageView
(iw x ih) now represents the actual rescaled (width x height) for the image within the view (in other words the displayed size of the image)
EDIT: I think a nicer way to write the above answer (and one that works with ints) :
final int actualHeight, actualWidth;
final int imageViewHeight = imageView.getHeight(), imageViewWidth = imageView.getWidth();
final int bitmapHeight = ..., bitmapWidth = ...;
if (imageViewHeight * bitmapWidth <= imageViewWidth * bitmapHeight) {
actualWidth = bitmapWidth * imageViewHeight / bitmapHeight;
actualHeight = imageViewHeight;
} else {
actualHeight = bitmapHeight * imageViewWidth / bitmapWidth;
actualWidth = imageViewWidth;
}
return new Point(actualWidth,actualHeight);
Here is a helper function to get the bounds of image in an imageView.
/**
* Helper method to get the bounds of image inside the imageView.
*
* @param imageView the imageView.
* @return bounding rectangle of the image.
*/
public static RectF getImageBounds(ImageView imageView) {
RectF bounds = new RectF();
Drawable drawable = imageView.getDrawable();
if (drawable != null) {
imageView.getImageMatrix().mapRect(bounds, new RectF(drawable.getBounds()));
}
return bounds;
}
I guess a lot of people are coming from this example https://developer.android.com/training/animation/zoom.html and don't want to use android:scaleType="centerCrop" (maybe because the ImageView is a constraint within the layout) don't you worry, I got your back!
Just replace the entire block beginning with
// Adjust the start bounds to be the same aspect ratio as the final
// bounds using the "center crop" technique.
with the following
//adjust for scaled image to constraint
int realheight = ResourcesCompat.getDrawable(getResources(),imageResId,null).getIntrinsicHeight();
int realwidth = ResourcesCompat.getDrawable(getResources(),imageResId,null).getIntrinsicWidth();
// Adjust the start bounds to be the same aspect ratio as the final
// bounds using ueen's adjusteddimensions technique. This prevents undesirable
// stretching during the animation. Also calculate the start scaling
// factor (the end scaling factor is always 1.0).
float startScale;
if ((float) finalBounds.width() / finalBounds.height()
> (float) startBounds.width() / startBounds.height()) {
// Extend start bounds horizontally
int adjustedheight = realheight*startBounds.width()/realwidth;
int adjustedoffset = (startBounds.height()-adjustedheight) / 2;
startScale = (float) adjustedheight / finalBounds.height();
float startWidth = startScale * finalBounds.width();
float deltaWidth = (startWidth - startBounds.width()) / 2;
startBounds.left -= deltaWidth;
startBounds.right += deltaWidth;
startBounds.offset(+0, +adjustedoffset);
} else {
// Extend start bounds vertically
int adjustedwidth = realwidth*startBounds.height()/realheight;
int adjustedoffset = (startBounds.width()-adjustedwidth) / 2;
startScale = (float) adjustedwidth / finalBounds.width();
Log.d("dfs", startBounds.width()+" - "+realwidth+" - " + adjustedwidth);
float startHeight = startScale * finalBounds.height();
float deltaHeight = (startHeight - startBounds.height()) / 2;
startBounds.top -= deltaHeight;
startBounds.bottom += deltaHeight;
startBounds.offset(+adjustedoffset, +0);
}
works like a charme, you're welcome :)
use
// For getting imageview height
imgObj.getMeasuredHeight()
// For getting imageview width
imgObj.getMeasuredWidth();
//For getting image height inside ImageView
imgObj.getDrawable().getIntrinsicHeight();
//For getting image width inside ImageView
imgObj.getDrawable().getIntrinsicWidth();
来源:https://stackoverflow.com/questions/12463155/get-the-displayed-size-of-an-image-inside-an-imageview