我在我的应用程序中实现了新SwipeRefreshLayout组件，它适用于任何垂直视图，ListView例如GridView和ScrollView。
它在水平视图中表现得非常糟糕，例如HorizontalScrollView. 当向右或向左滚动时，SwipeRefreshLayout视图缓存触摸，阻止HorizontalScrollView接收它并开始垂直滚动以执行刷新。
ScrollView我尝试解决这个问题，因为我之前用ViewPager内部解决了垂直问题，requestDisallowInterceptTouchEvent但它没有用。我还注意到这个方法在原始SwipeRefreshLayout类中被覆盖而没有返回超级。谷歌的开发者留下了评论“ //Nope.”:)
因为SwipeRefreshLayout组件相对较新，我找不到解决水平滚动问题的解决方案，同时仍然允许滑动刷新视图以跟踪和处理垂直滚动，所以我想我会分享我的解决方案，希望它能节省一个小时或两个。
我通过扩展SwipeRefreshLayout和覆盖它来解决它onInterceptTouchEvent。在里面，我计算用户游走的 X 距离是否大于触摸斜率。如果是这样，则表示用户正在水平滑动，因此我返回false让子视图（HorizontalScrollView在本例中为）获取触摸事件。
public class CustomSwipeToRefresh extends SwipeRefreshLayout {
private int mTouchSlop;
private float mPrevX;
public CustomSwipeToRefresh(Context context, AttributeSet attrs) {
super(context, attrs);
mTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop();
}
@Override
public boolean onInterceptTouchEvent(MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
mPrevX = MotionEvent.obtain(event).getX();
break;
case MotionEvent.ACTION_MOVE:
final float eventX = event.getX();
float xDiff = Math.abs(eventX - mPrevX);
if (xDiff > mTouchSlop) {
return false;
}
}
return super.onInterceptTouchEvent(event);
}
}
如果你没有记住你已经拒绝了 ACTION_MOVE 事件的事实，那么如果用户回到你最初的 mPrevX 附近，你最终会接受它。
只需添加一个布尔值即可记住它。
public class CustomSwipeToRefresh extends SwipeRefreshLayout {
private int mTouchSlop;
private float mPrevX;
// Indicate if we've already declined the move event
private boolean mDeclined;
public CustomSwipeToRefresh(Context context, AttributeSet attrs) {
super(context, attrs);
mTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop();
}
@Override
public boolean onInterceptTouchEvent(MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
mPrevX = MotionEvent.obtain(event).getX();
mDeclined = false; // New action
break;
case MotionEvent.ACTION_MOVE:
final float eventX = event.getX();
float xDiff = Math.abs(eventX - mPrevX);
if (mDeclined || xDiff > mTouchSlop) {
mDeclined = true; // Memorize
return false;
}
}
return super.onInterceptTouchEvent(event);
}
}
Lior Iluz 提出的覆盖 onInterceptTouchEvent() 的解决方案有一个严重的问题。如果内容可滚动容器未完全向上滚动，则可能无法在相同的向上滚动手势中激活滑动刷新。实际上，当您开始滚动内部容器并无意中将手指水平移动超过mTouchSlop（默认为 8dp）时，建议的 CustomSwipeToRefresh 会拒绝此手势。因此，用户必须再次尝试开始刷新。这对用户来说可能看起来很奇怪。
我从支持库中提取了原始 SwipeRefreshLayout 的源代码到我的项目中，并重新编写了 onInterceptTouchEvent()。新的类名是TouchSafeSwipeRefreshLayout
private boolean mPendingActionDown;
private float mInitialDownY;
private float mInitialDownX;
private boolean mGestureDeclined;
@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
ensureTarget();
final int action = ev.getActionMasked();
int pointerIndex;
if (mReturningToStart && action == MotionEvent.ACTION_DOWN) {
mReturningToStart = false;
}
if (!isEnabled() || mReturningToStart || mRefreshing ) {
// Fail fast if we're not in a state where a swipe is possible
if (D) Log.e(LOG_TAG, "Fail because of not enabled OR refreshing OR returning to start. "+motionEventToShortText(ev));
return false;
}
switch (action) {
case MotionEvent.ACTION_DOWN:
setTargetOffsetTopAndBottom(mOriginalOffsetTop - mCircleView.getTop());
mActivePointerId = ev.getPointerId(0);
if ((pointerIndex = ev.findPointerIndex(mActivePointerId)) >= 0) {
if (mNestedScrollInProgress || canChildScrollUp()) {
if (D) Log.e(LOG_TAG, "Fail because of nested content is Scrolling. Set pending DOWN=true. "+motionEventToShortText(ev));
mPendingActionDown = true;
} else {
mInitialDownX = ev.getX(pointerIndex);
mInitialDownY = ev.getY(pointerIndex);
}
}
return false;
case MotionEvent.ACTION_MOVE:
if (mActivePointerId == INVALID_POINTER) {
if (D) Log.e(LOG_TAG, "Got ACTION_MOVE event but don't have an active pointer id.");
return false;
} else if (mGestureDeclined) {
if (D) Log.e(LOG_TAG, "Gesture was declined previously because of horizontal swipe");
return false;
} else if ((pointerIndex = ev.findPointerIndex(mActivePointerId)) < 0) {
return false;
} else if (mNestedScrollInProgress || canChildScrollUp()) {
if (D) Log.e(LOG_TAG, "Fail because of nested content is Scrolling. "+motionEventToShortText(ev));
return false;
} else if (mPendingActionDown) {
// This is the 1-st Move after content stops scrolling.
// Consider this Move as Down (a start of new gesture)
if (D) Log.e(LOG_TAG, "Consider this move as down - setup initial X/Y."+motionEventToShortText(ev));
mPendingActionDown = false;
mInitialDownX = ev.getX(pointerIndex);
mInitialDownY = ev.getY(pointerIndex);
return false;
} else if (Math.abs(ev.getX(pointerIndex) - mInitialDownX) > mTouchSlop) {
mGestureDeclined = true;
if (D) Log.e(LOG_TAG, "Decline gesture because of horizontal swipe");
return false;
}
final float y = ev.getY(pointerIndex);
startDragging(y);
if (!mIsBeingDragged) {
if (D) Log.d(LOG_TAG, "Waiting for dY to start dragging. "+motionEventToShortText(ev));
} else {
if (D) Log.d(LOG_TAG, "Dragging started! "+motionEventToShortText(ev));
}
break;
case MotionEvent.ACTION_POINTER_UP:
onSecondaryPointerUp(ev);
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_CANCEL:
mIsBeingDragged = false;
mGestureDeclined = false;
mPendingActionDown = false;
mActivePointerId = INVALID_POINTER;
break;
}
return mIsBeingDragged;
}
请参阅我在Github上的示例项目。
如果您使用 Tim Roes EnhancedListView
看到这个问题。我对我非常有用，因为他们添加了一个功能，可以检测何时开始滑动以及何时结束滑动。
当滑动开始时，我禁用 SwipeRefreshLayout，当滑动完成时，我启用 swipeRefreshLayout。
这是我所做的：
class HorizontalScrollViewWithDragListener
@JvmOverloads constructor(context: Context, attrs: AttributeSet? = null) : HorizontalScrollView(context, attrs) {
var draggingState: Boolean = false
set(value) {
if (field != value) {
field = value
listener?.invoke(value)
}
}
var listener: ((draggingState: Boolean) -> Unit)? = null
override fun onInterceptTouchEvent(ev: MotionEvent) =
super.onInterceptTouchEvent(ev)
.also { draggingState = it }
@SuppressLint("ClickableViewAccessibility")
override fun onTouchEvent(ev: MotionEvent) =
super.onTouchEvent(ev)
.also {
if(ev.action == MotionEvent.ACTION_UP) {
draggingState = false
}
}
}
然后我只是在设置代码中执行此操作：
myScrollView.listener = { refreshView.isEnabled = !it }