public override bool OnLayoutChild(
CoordinatorLayout parent, Java.Lang.Object childObject, int layoutDirection)
{
Debug.WriteLineIf(DebugTrace, $"OnLayoutChild");
View child = Android.Runtime.Extensions.JavaCast <View>(childObject);
if (ViewCompat.GetFitsSystemWindows(parent) && !ViewCompat.GetFitsSystemWindows(child))
{
ViewCompat.SetFitsSystemWindows(child, true);
}
int savedTop = child.Top;
// First let the parent lay it out
parent.OnLayoutChild(child, layoutDirection);
// Offset the bottom sheet
mParentHeight = parent.Height;
mMinOffset = Math.Max(0, mParentHeight - child.Height);
mMaxOffset = Math.Max(mParentHeight - mPeekHeight, mMinOffset);
mAnchorOffset = (int)Math.Max(mParentHeight * mAnchorThreshold, mMinOffset);
Debug.WriteLineIf(DebugTrace, $"offset computed => savedTop:{savedTop} mMinOffset:{mMinOffset} mMaxOffset:{mMaxOffset} mAnchorOffset:{mAnchorOffset} ");
if (mState == STATE_EXPANDED)
{
ViewCompat.OffsetTopAndBottom(child, mMinOffset);
}
else if (mState == STATE_ANCHOR)
{
ViewCompat.OffsetTopAndBottom(child, mAnchorOffset);
}
else if (mHideable && mState == STATE_HIDDEN)
{
ViewCompat.OffsetTopAndBottom(child, mParentHeight);
}
else if (mState == STATE_COLLAPSED)
{
ViewCompat.OffsetTopAndBottom(child, mMaxOffset);
}
else if (mState == STATE_DRAGGING || mState == STATE_SETTLING)
{
ViewCompat.OffsetTopAndBottom(child, savedTop - child.Top);
}
if (mViewDragHelper == null || mViewDragHelper.Handle == IntPtr.Zero)
{
mViewDragHelper = ViewDragHelper.Create(parent, mDragCallback);
}
mViewRef = new WeakReference <View>(child);
mNestedScrollingChildRef = new WeakReference <View>(findScrollingChild(child));
return(true);
}
/**
* 强制rootView下面的子View的FitsSystemWindows为false
*/
public static void forceFitsSystemWindows(ViewGroup viewGroup)
{
if (Build.VERSION.SdkInt >= BuildVersionCodes.Kitkat)
{
int count = viewGroup.ChildCount;// GetChildCount();
for (int i = 0; i < count; i++)
{
View view = viewGroup.GetChildAt(i);
if (view is ViewGroup)
{
forceFitsSystemWindows((ViewGroup)view);
}
else
{
if (ViewCompat.GetFitsSystemWindows(view))
{
view.SetFitsSystemWindows(false);
//ViewCompat.SetFitsSystemWindows(view, false);
}
}
}
}
}