Android开发实现自定义水平滚动的容器示例

public class HorizontalScrollView extends ViewGroup {  //手势  private GestureDetector mGestureDetector;  private HorizontalScroller mScroller;  private int curID;  //快速滑动  private boolean isFlying;  //--回调函数-------------------------------------  private OnChangeListener mListener;  public void setOnChangeListener(OnChangeListener listener) {    if (listener != null) {      mListener = listener;    }  }  public interface OnChangeListener{    void move2dest(int curID);  }  public HorizontalScrollView(Context context) {    this(context, null);  }  public HorizontalScrollView(Context context, AttributeSet attrs) {    this(context, attrs, 0);  }  public HorizontalScrollView(Context context, AttributeSet attrs, int defStyle) {    super(context, attrs, defStyle);    mScroller = new HorizontalScroller();    isFlying = false;    initGesture(context);  }  @Override  protected void onLayout(boolean changed, int l, int t, int r, int b) {    // 模向移动，    for (int i = 0; i < getChildCount(); i++) {      View view = getChildAt(i);      //给水平方向的每个view定位      view.layout(i * getWidth(), 0, getWidth() + i * getWidth(), getHeight());    }  }  @Override  protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {    for (int i = 0; i < getChildCount(); i++) {      View view = getChildAt(i);      view.measure(widthMeasureSpec, heightMeasureSpec);    }    super.onMeasure(widthMeasureSpec, heightMeasureSpec);  }  @Override  public boolean onTouchEvent(MotionEvent event) {    mGestureDetector.onTouchEvent(event);    switch (event.getAction()) {    case MotionEvent.ACTION_DOWN:      if (!isFlying) {        move2dest();      }      isFlying = false;      break;    case MotionEvent.ACTION_MOVE:      break;    case MotionEvent.ACTION_UP:      break;    default:      break;    }    return true;  }  public void move2dest() {    //    int destID = (getScrollX() + getWidth() / 2) / getWidth();    move2dest(destID);  }  public void move2dest(int destID) {    curID = destID;    if (destID > getChildCount() - 1) {      destID = getChildCount() - 1;    }    if (mListener != null) {      mListener.move2dest(curID);    }    int distance = (int) (destID * getWidth() - getScrollX());    // scrollBy(distance, 0);    mScroller.startScroll(getScrollX(), getScrollY(), distance, 0);    invalidate();  }    @Override  public void computeScroll() {    // 如果存在偏移，就不断刷新    if (mScroller.computeScrollOffset()) {      scrollTo(mScroller.getCurrX(), 0);      invalidate();    }    super.computeScroll();  }  private void initGesture(Context context) {    mGestureDetector = new GestureDetector(context, new OnGestureListener() {      @Override      public boolean onSingleTapUp(MotionEvent e) {        return false;      }      @Override      public void onShowPress(MotionEvent e) {      }      @Override      public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {        scrollBy((int) distanceX, 0);        return false;      }      @Override      public void onLongPress(MotionEvent e) {      }      @Override            public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {        isFlying = true;        if (curID > 0 && velocityX > 0) {// 表示向左移          move2dest(curID - 1);        } else if (curID < getChildCount() && velocityX < 0) {          move2dest(curID + 1);// 向右        } else {          move2dest();// 移到原位        }        return false;      }      @Override      public boolean onDown(MotionEvent e) {        return false;      }    });  }}