安卓View的滑动（scrollTo/scrollBy，layout,动画）

通过scrollTo,ScrollBy

public class DragView extends View {
    public DragView(Context context) {
        super(context);
    }

    public DragView(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
    }

    public DragView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init(context);
    }

    private void init(Context context){

    }


    private int startX;
    private int startY;

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        int x= (int) event.getX();
        int y= (int) event.getY();
        switch (event.getAction()){
            case MotionEvent.ACTION_DOWN:
                startX=x;
                startY=y;
                break;
            case MotionEvent.ACTION_MOVE:
                int distanceX=x-startX;//末位置-初始位置
                int distanceY=y-startY;
                ((View)getParent()).scrollBy(-distanceX,-distanceY);
                break;
            case MotionEvent.ACTION_POINTER_UP:
                break;
        }
        return true;
    }
}

通过layout()

public class LayoutView extends View{

    public LayoutView(Context context) {
        super(context);
    }

    public LayoutView(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
    }

    public LayoutView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    private int startX;
    private int startY;
    @Override
    public boolean onTouchEvent(MotionEvent event) {
        int x= (int) event.getX();
        int y= (int) event.getY();
        switch(event.getAction()){
            case MotionEvent.ACTION_DOWN:
                startX=x;
                startY=y;
                break;
            case MotionEvent.ACTION_MOVE:
                int distanceX=x-startY;
                int distanceY=y-startY;
                /**
                  layout()中的方法
                  getTop()获取到的是View自身顶边到父布局顶边的距离
                  getBottom()获取到的是View自身底边到父布局顶边的距离
                  getLeft()获取到的是View自身左边到父布局左边的距离
                  getRight()获取到的是View自身右边到父布局左边的距离
                 */
                layout(
                        getLeft()+distanceX,
                        getTop()+distanceY,
                        getRight()+distanceX,
                        getBottom()+distanceY
                );
                break;
            case MotionEvent.ACTION_UP:
                break;
        }
        return true;
    }
}

动画

ObjectAnimator.ofFloat(button,"translationX",0,100).setDuration(1000).start();//设置一秒内向右移动100像素