主要是重写RecyclerView的onInterceptTouchEvent方法
话不多说直接上代码:
public class CustomRecyclerView extends RecyclerView{
private static final int INVALID_POINTER = -1;
private int mScrollPointerId = INVALID_POINTER;
private int mInitialTouchX, mInitialTouchY;
private int mTouchSlop;
public CustomRecyclerView (Context context) {
this(context, null);
}
public CustomRecyclerView (Context context, @Nullable AttributeSet attrs) {
this(context, attrs, 0);
}
public CustomRecyclerView (Context context, @Nullable AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
final ViewConfiguration vc = ViewConfiguration.get(getContext());
mTouchSlop = vc.getScaledTouchSlop();
}
@Override
public void setScrollingTouchSlop(int slopConstant) {
super.setScrollingTouchSlop(slopConstant);
final ViewConfiguration vc = ViewConfiguration.get(getContext());
switch (slopConstant) {
case TOUCH_SLOP_DEFAULT:
mTouchSlop = vc.getScaledTouchSlop();
break;
case TOUCH_SLOP_PAGING:
mTouchSlop = ViewConfigurationCompat.getScaledPagingTouchSlop(vc);
break;
default:
break;
}
}
@Override
public boolean onInterceptTouchEvent(MotionEvent e) {
final int action = MotionEventCompat.getActionMasked(e);
final int actionIndex = MotionEventCompat.getActionIndex(e);
switch (action) {
case MotionEvent.ACTION_DOWN:
mScrollPointerId = MotionEventCompat.getPointerId(e, 0);
mInitialTouchX = (int) (e.getX() + 0.5f);
mInitialTouchY = (int) (e.getY() + 0.5f);
return super.onInterceptTouchEvent(e);
case MotionEventCompat.ACTION_POINTER_DOWN:
mScrollPointerId = MotionEventCompat.getPointerId(e, actionIndex);
mInitialTouchX = (int) (MotionEventCompat.getX(e, actionIndex) + 0.5f);
mInitialTouchY = (int) (MotionEventCompat.getY(e, actionIndex) + 0.5f);
return super.onInterceptTouchEvent(e);
case MotionEvent.ACTION_MOVE: {
final int index = MotionEventCompat.findPointerIndex(e, mScrollPointerId);
if (index < 0) {
return false;
}
final int x = (int) (MotionEventCompat.getX(e, index) + 0.5f);
final int y = (int) (MotionEventCompat.getY(e, index) + 0.5f);
if (getScrollState() != SCROLL_STATE_DRAGGING) {
final int dx = x - mInitialTouchX;
final int dy = y - mInitialTouchY;
final boolean canScrollHorizontally = getLayoutManager().canScrollHorizontally();
final boolean canScrollVertically = getLayoutManager().canScrollVertically();
boolean startScroll = false;
if (canScrollHorizontally && Math.abs(dx) > mTouchSlop && (Math.abs(dx) >= Math.abs(dy) || canScrollVertically)) {
startScroll = true;
}
if (canScrollVertically && Math.abs(dy) > mTouchSlop && (Math.abs(dy) >= Math.abs(dx) || canScrollHorizontally)) {
startScroll = true;
}
return startScroll && super.onInterceptTouchEvent(e);
}
return super.onInterceptTouchEvent(e);
}
default:
return super.onInterceptTouchEvent(e);
}
}
}
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