在无效之间保持动画状态

Question

我试图在无效后保存视图状态，但很不成功。

问题是我有一张图像，用户可以缩放（在右侧或左侧）。在他缩放之后，应用程序将在某些位置绘制点，在用户点击其中的一些位置后，我希望它发生变化（它是带有可选城市的地图）。

问题是点击该点后，我需要调用 invalidate() 再次调用 onDraw() - 以更改该点，但在使地图无效后，地图会恢复到其原始状态，因此它 "unzoomed"再次。你能告诉我，如何通过无效方法保留应用于视图的动画状态吗？

@Override
protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);

    if (zoomed) {
        Paint p //init Paint
        for (Location l : locations) {
            if (l.selected) {
                canvas.drawCircle(l.calculatedPixels.X, l.calculatedPixels.Y, pxFromDp(getContext(), 10), p);
            } else {
                canvas.drawCircle(l.calculatedPixels.X, l.calculatedPixels.Y, pxFromDp(getContext(), 5), p);
                p.setStyle(Paint.Style.STROKE);
                canvas.drawCircle(l.calculatedPixels.X, l.calculatedPixels.Y, pxFromDp(getContext(), 10), p);
            }
//NOTHING OF THIS WORKS CORRECTLY
        if (scaleByTownTouch && getScaleX() != scaleTo) {
            //canvas.restore();
            setScaleX(scaleTo);
            setScaleY(scaleTo);
            setPivotX(pivotX);
            setPivotY(pivotY);

            /*ScaleAnimation scaleAnimation = new ScaleAnimation(scaleFrom, scaleTo, scaleFrom, scaleTo, pivotX, pivotY);
            scaleAnimation.setDuration(0);
            scaleAnimation.setFillAfter(true);
            this.startAnimation(scaleAnimation);*/
            scaleByTownTouch = false;
        }
    }
}

@Override
public boolean onTouch(View v, MotionEvent event) {
    if (event.getAction() == MotionEvent.ACTION_DOWN) {
        if (zoomed) {
            for (Location l : locations) {
                if (l.calculatedPixels.isTouchNearPoint(event.getX(), event.getY(), 50, scaleTo)) {
                    l.selected = !l.selected;
                    scaleByTownTouch = true;
                    //THIS UNZOOMS WHOLE VIEW
                    invalidate();
                    return true;
                }
            }
            zoom(new Point());
        } else {
            float xTouch = event.getX();
            float yTouch = event.getY();
            Point touch = new Point();
            touch.X = xTouch / measuredX * 100;
            touch.Y = 100 - (yTouch / measuredY * 100);
            zoom(touch);
        }
    }
    return false;
}

public void zoom(Point touch) {
    if (!scaleByTownTouch) {
        if (!zoomed) {
            if (!touch.isBelowLine()) {
                pivotX = measuredX;
                pivotY = measuredY;
                scaleTo = 1.7f;
            } else {
                pivotX = 0;
                pivotY = 0;
                scaleTo = 1.5f;
            }
            scaleFrom = 1;
        } else {
            scaleFrom = scaleTo;
            scaleTo = 1;
        }

        final MapImageView miv = this;
        ScaleAnimation scaleAnimation = new ScaleAnimation(scaleFrom, scaleTo, scaleFrom, scaleTo, pivotX, pivotY);
        scaleAnimation.setDuration(1000);
        scaleAnimation.setFillAfter(true);
        scaleAnimation.setAnimationListener(new Animation.AnimationListener() {
            @Override
            public void onAnimationEnd(Animation animation) {
                zoomed = !zoomed;
                miv.invalidate();
            }
        });
        this.startAnimation(scaleAnimation);
    }
}

Answer 1

您应该尝试使用 Animator 而不是 Animation。动画仅更改渲染，而 Animator 更改对象的属性，该对象将在失效后保留。

看看 ValueAnimator 或 ObjectAnimator。

在无效之间保持动画状态

Hold animation state between invalidate

android

animation

scale

android-view-invalidate