缩放动画不会改变 ImageView 的大小

Question

我正在创建一个应用程序，它从资源中加载可绘制对象并将其显示在占位符 ImageView 中。当用户单击按钮加载下一张图片时，我创建了一个动画，它会移动并缩放旧图像到新位置并将新的可绘制对象加载到占位符。

30 张图片后，我运行 OOM，这是有道理的。

我想做的是在动画结束后对每个图像重新采样，因为我从 500X500 占位符开始，以 1/3 结束。

问题是在我完成动画后，ImageView 的宽度和高度保持不变。缩放动画不应该改变ImageView的宽度和高度吗？

这是动画代码：

    //create the animation
    imageView.setPivotX(0);
    imageView.setPivotY(0);
    imageView.animate()
             .scaleX(scaleX) //about 0.3
             .scaleY(scaleY) //about 0.3
             .x(finalX) //location x of the image
             .y(finalY) //location y of the image
             .setListener(new Animator.AnimatorListener() {
                        @Override
                        public void onAnimationStart(Animator animation) {
                            int reqWidth = imageView.getWidth(); //result 500 as expected
                            int reqHeight = imageView.getHeight();//result 500 as expected
                            Drawable image = imageView.getDrawable();
                        }

                        @Override
                        public void onAnimationEnd(Animator animation) {
                            int reqWidth = imageView.getWidth();//result 500 - why?
                            int reqHeight = imageView.getHeight();//result 500 - why?
                            Drawable image = imageView.getDrawable();
                        }

                        @Override
                        public void onAnimationCancel(Animator animation) {}

                        @Override
                        public void onAnimationRepeat(Animator animation) {}
                    });

Answer 1

scaleX() 使 View 的 scaleX 属性动画到指定值 (reference). It doesn't directly change the layout width/height values. (reference)

您可以通过乘以 scaleX/Y 值来获得预期的 width/height 值。

//create the animation
    imageView.setPivotX(0);
    imageView.setPivotY(0);
    imageView.animate()
             .scaleX(scaleX) //about 0.3
             .scaleY(scaleY) //about 0.3
             .x(finalX) //location x of the image
             .y(finalY) //location y of the image
             .setListener(new Animator.AnimatorListener() {
                        @Override
                        public void onAnimationStart(Animator animation) {
                            int reqWidth = imageView.getWidth(); //result 500 as expected
                            int reqHeight = imageView.getHeight();//result 500 as expected
                            Drawable image = imageView.getDrawable();
                        }

                        @Override
                        public void onAnimationEnd(Animator animation) {
                            int reqWidth = imageView.getWidth() * imageView.getScaleX;
                            int reqHeight = imageView.getHeight() * imageView.getScaleY;
                            Drawable image = imageView.getDrawable();
                        }

                        @Override
                        public void onAnimationCancel(Animator animation) {}

                        @Override
                        public void onAnimationRepeat(Animator animation) {}
                    });

缩放动画不会改变 ImageView 的大小

Scaling animation doesn't change the ImageView size

android

scale

android-animation