android view 动画详解

Interpolator 和 属性动画结合使用 ：

private static class WorkspaceOvershootInterpolator implements Interpolator {
        private static final float DEFAULT_TENSION = 1.3f;
        private float mTension;

        public WorkspaceOvershootInterpolator() {
            mTension = DEFAULT_TENSION;
        }

        public void setDistance(int distance) {
            mTension = distance > 0 ? DEFAULT_TENSION / distance : DEFAULT_TENSION;
        }

        public void disableSettle() {
            mTension = 0.f;
        }

        public float getInterpolation(float t) {
            // _o(t) = t * t * ((tension + 1) * t + tension)
            // o(t) = _o(t - 1) + 1
            t -= 1.0f;
            return t * t * ((mTension + 1) * t + mTension) + 1.0f;
        }
    }

TextView tv = (TextView) this.findViewById(R.id.tv);
        ObjectAnimator oa = ObjectAnimator.ofFloat(tv, "scaleX", 0f, 1f);
        oa.setDuration(3000);
        oa.setInterpolator(new WorkspaceOvershootInterpolator());

        oa.addListener(new AnimatorListenerAdapter() {
            public void onAnimationEnd(Animator animation) {
                Log.i("Animation", "end");
            }
        });
        oa.start();

如何移动一个view

1.动画

2.调用layout

 public static class LayoutParams extends FrameLayout.LayoutParams {
        public int x, y;
        public boolean customPosition = false;

        /**
         * {@inheritDoc}
         */
        public LayoutParams(int width, int height) {
            super(width, height);
        }

        public void setWidth(int width) {
            this.width = width;
        }

        public int getWidth() {
            return width;
        }

        public void setHeight(int height) {
            this.height = height;
        }

        public int getHeight() {
            return height;
        }

        public void setX(int x) {
            this.x = x;
        }

        public int getX() {
            return x;
        }

        public void setY(int y) {
            this.y = y;
        }

        public int getY() {
            return y;
        }
    }

    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        super.onLayout(changed, l, t, r, b);
        int count = getChildCount();
        for (int i = 0; i < count; i++) {
            View child = getChildAt(i);
            final FrameLayout.LayoutParams flp = (FrameLayout.LayoutParams) child.getLayoutParams();
            if (flp instanceof LayoutParams) {
                final LayoutParams lp = (LayoutParams) flp;
                if (lp.customPosition) {
                    child.layout(lp.x, lp.y, lp.x + lp.width, lp.y + lp.height);
                }
            }
        }
    }

3.设置LayoutParam

	//----------------------------------------------------------
		ViewGroup  parentitem = (ViewGroup)this.getChildAt(2);
		View item = parentitem.getChildAt(0);
		//是哪一种 LayoutParams 由 item 的父视图的类型决定
		LinearLayout.LayoutParams layoutParams = (LinearLayout.LayoutParams) item.getLayoutParams();
		layoutParams.leftMargin = 100;
        item.setLayoutParams(layoutParams);
        item.invalidate();
        item.requestLayout();
 

4.scroller