我如何动画 View.setVisibility(GONE)

问题描述

我想为 View 的可见性设置为 GONE 时制作 Animation.View 应该折叠"而不是仅仅消失.我用 ScaleAnimation 尝试了这个，但是 View 被折叠了，但是布局只会在 Animation 停止之后(或之前)调整它的空间大小(或开始).

I want to make an Animation for when a View gets it's visibility set to GONE. Instead of just dissapearing, the View should 'collapse'. I tried this with a ScaleAnimation but then the View is collapse, but the layout will only resize it's space after (or before) the Animation stops (or starts).

如何制作 Animation 以便在动画时，较低的 View 将直接停留在内容下方，而不是有空格?

How can I make the Animation so that, while animating, the lower Views will stay directly below the content, instead of having a blank space?

推荐答案

通过 API 似乎没有简单的方法可以做到这一点，因为动画只是改变了视图的渲染矩阵，而不是实际大小.但是我们可以设置一个负边距来欺骗 LinearLayout 认为视图正在变小.

There doesn't seem to be an easy way to do this through the API, because the animation just changes the rendering matrix of the view, not the actual size. But we can set a negative margin to fool LinearLayout into thinking that the view is getting smaller.

因此，我建议基于 ScaleAnimation 创建您自己的 Animation 类，并覆盖applyTransformation"方法以设置新的边距和更新布局.像这样...

So I'd recommend creating your own Animation class, based on ScaleAnimation, and overriding the "applyTransformation" method to set new margins and update the layout. Like this...

public class Q2634073 extends Activity implements OnClickListener {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.q2634073);
        findViewById(R.id.item1).setOnClickListener(this);
    }

    @Override
    public void onClick(View view) {
        view.startAnimation(new MyScaler(1.0f, 1.0f, 1.0f, 0.0f, 500, view, true));
    }

    public class MyScaler extends ScaleAnimation {

        private View mView;

        private LayoutParams mLayoutParams;

        private int mMarginBottomFromY, mMarginBottomToY;

        private boolean mVanishAfter = false;

        public MyScaler(float fromX, float toX, float fromY, float toY, int duration, View view,
                boolean vanishAfter) {
            super(fromX, toX, fromY, toY);
            setDuration(duration);
            mView = view;
            mVanishAfter = vanishAfter;
            mLayoutParams = (LayoutParams) view.getLayoutParams();
            int height = mView.getHeight();
            mMarginBottomFromY = (int) (height * fromY) + mLayoutParams.bottomMargin - height;
            mMarginBottomToY = (int) (0 - ((height * toY) + mLayoutParams.bottomMargin)) - height;
        }

        @Override
        protected void applyTransformation(float interpolatedTime, Transformation t) {
            super.applyTransformation(interpolatedTime, t);
            if (interpolatedTime < 1.0f) {
                int newMarginBottom = mMarginBottomFromY
                        + (int) ((mMarginBottomToY - mMarginBottomFromY) * interpolatedTime);
                mLayoutParams.setMargins(mLayoutParams.leftMargin, mLayoutParams.topMargin,
                    mLayoutParams.rightMargin, newMarginBottom);
                mView.getParent().requestLayout();
            } else if (mVanishAfter) {
                mView.setVisibility(View.GONE);
            }
        }

    }

}

通常的警告适用:因为我们覆盖了一个受保护的方法 (applyTransformation)，所以不能保证这在未来的 Android 版本中有效.

The usual caveat applies: because we are overriding a protected method (applyTransformation), this is not guaranteed to work in future versions of Android.

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