先看下佈局php
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/coordinator" android:layout_width="match_parent" android:layout_height="match_parent"> <android.support.design.widget.AppBarLayout android:id="@+id/appbar" android:layout_width="match_parent" android:layout_height="wrap_content"> <!--這個是滾動頭部--> <include layout="@layout/include_find_header"/> <!--這個是吸頂佈局--> <include layout="@layout/include_sticky_header"/> </android.support.design.widget.AppBarLayout> <!--app:layout_behavior 屬性,該佈局包含一個豎直方向的RecyclerView--> <include layout="@layout/include_recycler_view" /> </android.support.design.widget.CoordinatorLayout>
出現的問題android
CoordinatorLayout向上fling滾動沒法被外部中斷git
RecyclerView向下fling滾動github
分析一下HeaderBehavior面試
AppBarLayout簡單說明segmentfault
按個人理解,AppBarLayout內部有2種view,一種可滑出(屏幕),另外一種不可滑出,根據app:layout_scrollFlags區分。通常上邊放可滑出的下邊放不可滑出的。
AppBarLayout.Behavior部分方法說明markdown
經過反射拿到flingRunnable變量,注意這裏我判斷了一下27和28版本的問題,27及如下是mFlingRunnable,28及以上是flingRunnable,必定要注意這個問題。app
/** * 反射獲取私有的flingRunnable 屬性,考慮support 28之後變量名修改的問題 * @return Field
*/ private Field getFlingRunnableField() throws NoSuchFieldException { Class<?> superclass = this.getClass().getSuperclass(); try { // support design 27及一下版本 Class<?> headerBehaviorType = null; if (superclass != null) { String name = superclass.getName(); LogUtil.d("AppBarLayout.Behavior父類",name); headerBehaviorType = superclass.getSuperclass(); } if (headerBehaviorType != null) { String name = headerBehaviorType.getName(); LogUtil.d("AppBarLayout.Behavior父類的父類1",name); return headerBehaviorType.getDeclaredField("mFlingRunnable"); }else { return null; } } catch (NoSuchFieldException e) { e.printStackTrace(); // 多是28及以上版本 Class<?> headerBehaviorType = superclass.getSuperclass().getSuperclass(); if (headerBehaviorType != null) { String name = headerBehaviorType.getName(); LogUtil.d("AppBarLayout.Behavior父類的父類2",name); return headerBehaviorType.getDeclaredField("flingRunnable"); } else { return null; } } } ```
經過反射拿到scroller變量,和上面相似。ide
/** * 反射獲取私有的scroller 屬性,考慮support 28之後變量名修改的問題 * @return Field
*/ private Field getScrollerField() throws NoSuchFieldException { Class<?> superclass = this.getClass().getSuperclass(); try { // support design 27及一下版本 Class<?> headerBehaviorType = null; if (superclass != null) { headerBehaviorType = superclass.getSuperclass(); } if (headerBehaviorType != null) { return headerBehaviorType.getDeclaredField("mScroller"); }else { return null; } } catch (NoSuchFieldException e) { e.printStackTrace(); // 多是28及以上版本 Class<?> headerBehaviorType = superclass.getSuperclass().getSuperclass(); if (headerBehaviorType != null) { return headerBehaviorType.getDeclaredField("scroller"); }else { return null; } } } ```
而後在onInterceptTouchEvent攔截事件裏處理邏輯。當手指觸摸屏幕的時候中止fling事件佈局
@Override public boolean onInterceptTouchEvent(CoordinatorLayout parent, AppBarLayout child, MotionEvent ev) { LogUtil.d(TAG, "onInterceptTouchEvent:" + child.getTotalScrollRange()); shouldBlockNestedScroll = isFlinging; switch (ev.getActionMasked()) { case MotionEvent.ACTION_DOWN: //手指觸摸屏幕的時候中止fling事件 stopAppbarLayoutFling(child); break; default: break; } return super.onInterceptTouchEvent(parent, child, ev); } /** * 中止appbarLayout的fling事件
*/ private void stopAppbarLayoutFling(AppBarLayout appBarLayout) { //經過反射拿到HeaderBehavior中的flingRunnable變量 try { Field flingRunnableField = getFlingRunnableField(); Field scrollerField = getScrollerField(); if (flingRunnableField != null) { flingRunnableField.setAccessible(true); } if (scrollerField != null) { scrollerField.setAccessible(true); } Runnable flingRunnable = null; if (flingRunnableField != null) { flingRunnable = (Runnable) flingRunnableField.get(this); } OverScroller overScroller = null; if (scrollerField != null) { overScroller = (OverScroller) scrollerField.get(this); } //下面是關鍵點 if (flingRunnable != null) { LogUtil.d(TAG, "存在flingRunnable"); appBarLayout.removeCallbacks(flingRunnable); flingRunnableField.set(this, null); } if (overScroller != null && !overScroller.isFinished()) { overScroller.abortAnimation(); } } catch (NoSuchFieldException e) { e.printStackTrace(); } catch (IllegalAccessException e) { e.printStackTrace(); } } ```
完整版本的代碼以下所示
/** * <pre> * @author yangchong * blog : https://github.com/yangchong211 * time : 2019/03/13 * desc : 自定義Behavior * revise: 解決appbarLayout若干問題 * 1)快速滑動appbarLayout會出現回彈 * 2)快速滑動appbarLayout到摺疊狀態下,立馬下滑,會出現抖動的問題 * 3)滑動appbarLayout,沒法經過手指按下讓其中止滑動
*/ public class AppBarLayoutBehavior extends AppBarLayout.Behavior { private static final String TAG = "AppbarLayoutBehavior"; private static final int TYPE_FLING = 1; private boolean isFlinging; private boolean shouldBlockNestedScroll; public AppBarLayoutBehavior(Context context, AttributeSet attrs) { super(context, attrs); } @Override public boolean onInterceptTouchEvent(CoordinatorLayout parent, AppBarLayout child, MotionEvent ev) { LogUtil.d(TAG, "onInterceptTouchEvent:" + child.getTotalScrollRange()); shouldBlockNestedScroll = isFlinging; switch (ev.getActionMasked()) { case MotionEvent.ACTION_DOWN: //手指觸摸屏幕的時候中止fling事件 stopAppbarLayoutFling(child); break; default: break; } return super.onInterceptTouchEvent(parent, child, ev); } /** * 反射獲取私有的flingRunnable 屬性,考慮support 28之後變量名修改的問題 * @return Field * @throws NoSuchFieldException */ private Field getFlingRunnableField() throws NoSuchFieldException { Class<?> superclass = this.getClass().getSuperclass(); try { // support design 27及一下版本 Class<?> headerBehaviorType = null; if (superclass != null) { headerBehaviorType = superclass.getSuperclass(); } if (headerBehaviorType != null) { return headerBehaviorType.getDeclaredField("mFlingRunnable"); }else { return null; } } catch (NoSuchFieldException e) { e.printStackTrace(); // 多是28及以上版本 Class<?> headerBehaviorType = superclass.getSuperclass().getSuperclass(); if (headerBehaviorType != null) { return headerBehaviorType.getDeclaredField("flingRunnable"); } else { return null; } } } /** * 反射獲取私有的scroller 屬性,考慮support 28之後變量名修改的問題 * @return Field * @throws NoSuchFieldException */ private Field getScrollerField() throws NoSuchFieldException { Class<?> superclass = this.getClass().getSuperclass(); try { // support design 27及一下版本 Class<?> headerBehaviorType = null; if (superclass != null) { headerBehaviorType = superclass.getSuperclass(); } if (headerBehaviorType != null) { return headerBehaviorType.getDeclaredField("mScroller"); }else { return null; } } catch (NoSuchFieldException e) { e.printStackTrace(); // 多是28及以上版本 Class<?> headerBehaviorType = superclass.getSuperclass().getSuperclass(); if (headerBehaviorType != null) { return headerBehaviorType.getDeclaredField("scroller"); }else { return null; } } } /** * 中止appbarLayout的fling事件 * @param appBarLayout */ private void stopAppbarLayoutFling(AppBarLayout appBarLayout) { //經過反射拿到HeaderBehavior中的flingRunnable變量 try { Field flingRunnableField = getFlingRunnableField(); Field scrollerField = getScrollerField(); if (flingRunnableField != null) { flingRunnableField.setAccessible(true); } if (scrollerField != null) { scrollerField.setAccessible(true); } Runnable flingRunnable = null; if (flingRunnableField != null) { flingRunnable = (Runnable) flingRunnableField.get(this); } OverScroller overScroller = (OverScroller) scrollerField.get(this); if (flingRunnable != null) { LogUtil.d(TAG, "存在flingRunnable"); appBarLayout.removeCallbacks(flingRunnable); flingRunnableField.set(this, null); } if (overScroller != null && !overScroller.isFinished()) { overScroller.abortAnimation(); } } catch (NoSuchFieldException e) { e.printStackTrace(); } catch (IllegalAccessException e) { e.printStackTrace(); } } @Override public boolean onStartNestedScroll(CoordinatorLayout parent, AppBarLayout child, View directTargetChild, View target, int nestedScrollAxes, int type) { LogUtil.d(TAG, "onStartNestedScroll"); stopAppbarLayoutFling(child); return super.onStartNestedScroll(parent, child, directTargetChild, target, nestedScrollAxes, type); } @Override public void onNestedPreScroll(CoordinatorLayout coordinatorLayout, AppBarLayout child, View target, int dx, int dy, int[] consumed, int type) { LogUtil.d(TAG, "onNestedPreScroll:" + child.getTotalScrollRange() + " ,dx:" + dx + " ,dy:" + dy + " ,type:" + type); //type返回1時,表示當前target處於非touch的滑動, //該bug的引發是由於appbar在滑動時,CoordinatorLayout內的實現NestedScrollingChild2接口的滑動 //子類還未結束其自身的fling //因此這裏監聽子類的非touch時的滑動,而後block掉滑動事件傳遞給AppBarLayout if (type == TYPE_FLING) { isFlinging = true; } if (!shouldBlockNestedScroll) { super.onNestedPreScroll(coordinatorLayout, child, target, dx, dy, consumed, type); } } @Override public void onNestedScroll(CoordinatorLayout coordinatorLayout, AppBarLayout child, View target, int dxConsumed, int dyConsumed, int dxUnconsumed, int dyUnconsumed, int type) { LogUtil.d(TAG, "onNestedScroll: target:" + target.getClass() + " ," + child.getTotalScrollRange() + " ,dxConsumed:" + dxConsumed + " ,dyConsumed:" + dyConsumed + " " + ",type:" + type); if (!shouldBlockNestedScroll) { super.onNestedScroll(coordinatorLayout, child, target, dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed, type); } } @Override public void onStopNestedScroll(CoordinatorLayout coordinatorLayout, AppBarLayout abl, View target, int type) { LogUtil.d(TAG, "onStopNestedScroll"); super.onStopNestedScroll(coordinatorLayout, abl, target, type); isFlinging = false; shouldBlockNestedScroll = false; } private static class LogUtil{ static void d(String tag, String string){ Log.d(tag,string); } } } ```
代碼以下所示
<android.support.design.widget.AppBarLayout android:id="@+id/appbar" app:layout_behavior="org.yczbj.ycrefreshview.sticky.AppBarLayoutBehavior" android:layout_width="match_parent" android:layout_height="wrap_content">
發現最終解決問題