onInterceptTouchEvent不幸的是，由于上述原因，您不能依赖 SlidingUpPanelLayout 的方法。一旦子视图的onTouchEvent方法返回true,onInterceptTouchEvent就不再被调用。
我的解决方案有点复杂，但它可以让您准确地实现（我认为）您正在寻找的东西。单个触摸/拖动事件会将面板拖动到位，一旦到位，继续滚动子视图。同样，向下拖动时，单个触摸/拖动事件可以滚动子视图，一旦完全滚动，将开始向下拖动面板。
更新 2015-04-12更新到 SlidingUpPanelLayout 代码的 3.0.0 版。还考虑 ListViews 而不仅仅是 ScrollViews。
1）
在res/SlidingUpPanel的库项目文件夹中，打开attrs.xml并添加
<attr name="scrollView" format="reference" />
您将使用它来识别单个子视图，一旦面板被拖动到位，它将篡夺触摸事件。在您的布局 xml 文件中，您可以添加
sothree:scrollView="@+id/myScrollView"
或者你的 scrollView 的 ID 是什么。还要确保你没有声明一个sothree:dragViewID，所以整个视图都是可拖动的。
其余步骤均在SlidingUpPanelLayout.java...内完成
2)
声明以下变量：
View mScrollView;
int mScrollViewResId = -1;
boolean isChildHandlingTouch = false;
float mPrevMotionX;
float mPrevMotionY;
3)在构造函数中，在mDragViewResId设置之后，添加以下行：
mScrollViewResId = ta.getResourceId(R.styleable.SlidingUpPanelLayout_scrollView, -1);
4)
在onFinishInflate中，添加以下代码：
if (mScrollViewResId != -1) {
mScrollView = findViewById(mScrollViewResId);
}
5）
添加以下方法：
private boolean isScrollViewUnder(int x, int y) {
if (mScrollView == null)
return false;
int[] viewLocation = new int[2];
mScrollView.getLocationOnScreen(viewLocation);
int[] parentLocation = new int[2];
this.getLocationOnScreen(parentLocation);
int screenX = parentLocation[0] + x;
int screenY = parentLocation[1] + y;
return screenX >= viewLocation[0] &&
screenX < viewLocation[0] + mScrollView.getWidth() &&
screenY >= viewLocation[1] &&
screenY < viewLocation[1] + mScrollView.getHeight();
}
6）
删除onInterceptTouchEvent。
7）
修改onTouchEvent如下：
public boolean onTouchEvent(MotionEvent ev) {
if (!isEnabled() || !isTouchEnabled()) {
return super.onTouchEvent(ev);
}
try {
mDragHelper.processTouchEvent(ev);
final int action = ev.getAction();
boolean wantTouchEvents = false;
switch (action & MotionEventCompat.ACTION_MASK) {
case MotionEvent.ACTION_UP: {
final float x = ev.getX();
final float y = ev.getY();
final float dx = x - mInitialMotionX;
final float dy = y - mInitialMotionY;
final int slop = mDragHelper.getTouchSlop();
View dragView = mDragView != null ? mDragView : mSlideableView;
if (dx * dx + dy * dy < slop * slop &&
isDragViewUnder((int) x, (int) y) &&
!isScrollViewUnder((int) x, (int) y)) {
dragView.playSoundEffect(SoundEffectConstants.CLICK);
if ((PanelState.EXPANDED != mSlideState) && (PanelState.ANCHORED != mSlideState)) {
setPanelState(PanelState.ANCHORED);
} else {
setPanelState(PanelState.COLLAPSED);
}
break;
}
break;
}
}
return wantTouchEvents;
} catch (Exception ex) {
ex.printStackTrace();
return false;
}
}
8）
添加以下方法：
@Override
public boolean dispatchTouchEvent(MotionEvent ev) {
// Identify if we want to handle the touch event in this class.
// We do this here because we want to be able to handle the case
// where a child begins handling a touch event, but then the
// parent takes over. If we rely on onInterceptTouchEvent, we
// lose control of the touch as soon as the child handles the event.
if (mScrollView == null)
return super.dispatchTouchEvent(ev);
final int action = MotionEventCompat.getActionMasked(ev);
final float x = ev.getX();
final float y = ev.getY();
if (action == MotionEvent.ACTION_DOWN) {
// Go ahead and have the drag helper attempt to intercept
// the touch event. If it won't be dragging, we'll cancel it later.
mDragHelper.shouldInterceptTouchEvent(ev);
mInitialMotionX = mPrevMotionX = x;
mInitialMotionY = mPrevMotionY = y;
isChildHandlingTouch = false;
} else if (action == MotionEvent.ACTION_MOVE) {
float dx = x - mPrevMotionX;
float dy = y - mPrevMotionY;
mPrevMotionX = x;
mPrevMotionY = y;
// If the scroll view isn't under the touch, pass the
// event along to the dragView.
if (!isScrollViewUnder((int) x, (int) y))
return this.onTouchEvent(ev);
// Which direction (up or down) is the drag moving?
if (dy > 0) { // DOWN
// Is the child less than fully scrolled?
// Then let the child handle it.
if (isScrollViewScrolling()) {
isChildHandlingTouch = true;
return super.dispatchTouchEvent(ev);
}
// Was the child handling the touch previously?
// Then we need to rejigger things so that the
// drag panel gets a proper down event.
if (isChildHandlingTouch) {
// Send an 'UP' event to the child.
MotionEvent up = MotionEvent.obtain(ev);
up.setAction(MotionEvent.ACTION_UP);
super.dispatchTouchEvent(up);
up.recycle();
// Send a 'DOWN' event to the panel. (We'll cheat
// and hijack this one)
ev.setAction(MotionEvent.ACTION_DOWN);
}
isChildHandlingTouch = false;
return this.onTouchEvent(ev);
} else if (dy < 0) { // UP
// Is the panel less than fully expanded?
// Then we'll handle the drag here.
if (mSlideOffset < 1.0f) {
isChildHandlingTouch = false;
return this.onTouchEvent(ev);
}
// Was the panel handling the touch previously?
// Then we need to rejigger things so that the
// child gets a proper down event.
if (!isChildHandlingTouch) {
mDragHelper.cancel();
ev.setAction(MotionEvent.ACTION_DOWN);
}
isChildHandlingTouch = true;
return super.dispatchTouchEvent(ev);
}
} else if ((action == MotionEvent.ACTION_CANCEL) ||
(action == MotionEvent.ACTION_UP)) {
if (!isChildHandlingTouch) {
final float dx = x - mInitialMotionX;
final float dy = y - mInitialMotionY;
final int slop = mDragHelper.getTouchSlop();
if ((mIsUsingDragViewTouchEvents) && (dx * dx + dy * dy < slop * slop))
return super.dispatchTouchEvent(ev);
return this.onTouchEvent(ev);
}
}
// In all other cases, just let the default behavior take over.
return super.dispatchTouchEvent(ev);
}
9）添加如下方法判断scrollView是否还在滚动。处理 ScrollView 和 ListView 的情况：
/**
* Computes the scroll position of the the scrollView, if set.
* @return
*/
private boolean isScrollViewScrolling() {
if (mScrollView == null)
return false;
// ScrollViews are scrolling when getScrollY() is a value greater than 0.
if (mScrollView instanceof ScrollView) {
return (mScrollView.getScrollY() > 0);
}
// ListViews are scrolling if the first child is not displayed, or if the first child has an offset > 0
else if (mScrollView instanceof ListView) {
ListView lv = (ListView) mScrollView;
if (lv.getFirstVisiblePosition() > 0)
return true;
View v = lv.getChildAt(0);
int top = (v == null) ? (0) : (-v.getTop() + lv.getFirstVisiblePosition() * lv.getHeight());
return top > 0;
}
return false;
}
10）（可选）添加如下方法让你在运行时设置scrollView（即你想在面板中放置一个fragment，并且fragment的child有一个你想要滚动的ScrollView/ListView）：
public void setScrollView(View scrollView) {
mScrollView = scrollView;
}
我们现在在这个类中完全管理触摸事件的处理。如果我们向上拖动面板并且它完全滑入到位，我们取消拖动，然后欺骗mScrollView孩子的新触摸。如果我们滚动孩子并到达顶部，我们会在孩子中欺骗“向上”事件并欺骗新的拖动触摸。这也允许其他子小部件上的点击事件。
已知问题
我们欺骗的“向上”/“向下”事件可能会无意中触发滚动视图子元素上的单击事件。