Android中实现滑动的七种方式总结

public class DragView extends View {
  privatE int mLastX;
  privatE int mLastY;
  //声明Scroller变量
  private Scroller mScroller;
  public DragView(Context context) {
    this(context,defStyleAttr);
    //在构造方法中初始化Scroller变量
    mScroller = new Scroller(context);
  }

  @Override
  public Boolean onTouchEvent(MotionEvent event) {
    int x = (int) event.getRawX();
    int y = (int) event.getRawY();
    switch (event.getAction()){
      case MotionEvent.ACTION_DOWN:
        mLastX = x;
        mLastY = y;
        break;
      case MotionEvent.ACTION_MOVE:
        int offsetX = x - mLastX;
        int offsetY = y - mLastY;
        //实现View跟随手指移动的效果
        ((View)getParent()).scrollBy(-offsetX,-offsetY);
        //重新设置初始坐标
        mLastX = x;
        mLastY = y;
        break;
      case MotionEvent.ACTION_UP:
        //当手指抬起时执行滑动过程
        View view = (View) getParent();
        mScroller.startScroll(view.getScrollX(),view.getScrollY(),view.getScrollX(),5000);
        //调用重绘来间接调用computeScroll()方法
        invalidate();
        break;
    }
    return true;
  }

  @Override
  public void computeScroll() {
    super.computeScroll();
    //判断滑动过程是否完成
    if (mScroller.computeScrollOffset()){
      ((View)getParent()).scrollTo(mScroller.getCurrX(),mScroller.getCurrY());
      //通过重绘来不断调用computeScroll()方法
      invalidate();
    }
  }
}

/**
 * Start scrolling by providing a starTing point,the distance to travel,* and the duration of the scroll.
 *
 * @param startX StarTing horizontal scroll offset in pixels. Positive
 *    numbers will scroll the content to the left.
 * @param startY StarTing vertical scroll offset in pixels. Positive numbers
 *    will scroll the content up.
 * @param dx Horizontal distance to travel. Positive numbers will scroll the
 *    content to the left.
 * @param dy Vertical distance to travel. Positive numbers will scroll the
 *    content up.
 * @param duration Duration of the scroll in milliseconds.
 */
public void startScroll(int startX,int startY,int dx,int dy,int duration)