CoordinatorLayout 解決滑動不跟手問題

滑動coordinatorLayout 後不跟手，反向滑動不能暫停之前的滑動。需要在AppBarLayout使用自定義的behavior

效果圖

首先，新建behavior文件AppBarLayoutBehavior.java

 

import android.content.Context;
import android.support.design.widget.AppBarLayout;
import android.support.design.widget.CoordinatorLayout;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.widget.OverScroller;

import java.lang.reflect.Field;

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停止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以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();
            // 可能是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以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();
            // 可能是28及以上版本
            Class<?> headerBehaviorType = superclass.getSuperclass().getSuperclass();
            if (headerBehaviorType != null) {
                return headerBehaviorType.getDeclaredField("scroller");
            }else {
                return null;
            }
        }
    }

    /**
     * 停止appbarLayout的fling事件
     * @param appBarLayout
     */
    private void stopAppbarLayoutFling(AppBarLayout appBarLayout) {
        //通過反射拿到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的引起是因爲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
        //所以這裏監聽子類的非touch時的滑動，然後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);
        }
    }

}

 

整個頁面佈局：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/parentLayout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true">

    <RelativeLayout
        android:id="@+id/tool"
        style="@style/topbar_bg"
        android:background="@color/titleColor">

        <ImageView style="@style/topbar_return_img" />

        <LinearLayout
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_centerInParent="true"
            android:gravity="center"
            android:orientation="vertical">

            <TextView
                android:id="@+id/titleText"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="@string/details"
                android:textColor="@color/white"
                android:textSize="16sp" />

        </LinearLayout>

    </RelativeLayout>

    <android.support.design.widget.CoordinatorLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_above="@+id/bottomLayout"
        android:layout_below="@+id/tool"
        android:fitsSystemWindows="true">

        <android.support.design.widget.AppBarLayout
            android:id="@+id/app_bar"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:fitsSystemWindows="true"
            app:layout_behavior=".utils.AppBarLayoutBehavior">

            <android.support.design.widget.CollapsingToolbarLayout
                android:id="@+id/toolbar_layout"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:fitsSystemWindows="true"
                app:layout_scrollFlags="scroll|exitUntilCollapsed"
                app:statusBarScrim="@android:color/transparent">

                <LinearLayout
                    android:id="@+id/itemLayout"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:background="@drawable/shape_press_bound"
                    android:orientation="vertical">

                    <RelativeLayout
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content"
                        android:layout_marginLeft="12dp"
                        android:layout_marginTop="10dp"
                        android:layout_marginRight="12dp"
                        android:layout_marginBottom="5dp">

                      

                        <TextView
                            android:id="@+id/postInfo"
                            android:layout_width="wrap_content"
                            android:layout_height="wrap_content"
                            android:layout_below="@+id/userName"
                            android:layout_alignLeft="@+id/userName"
                            android:layout_marginTop="8dp"
                            android:text=""
                            android:textColor="@color/second_text_color"
                            android:textSize="12sp" />

                       

                    </RelativeLayout>

               

                  

                    <View
                        android:layout_width="match_parent"
                        android:layout_height="1px"
                        android:layout_marginTop="15dp"
                        android:background="@color/color_background_grey" />

                </LinearLayout>

            </android.support.design.widget.CollapsingToolbarLayout>


            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:orientation="horizontal">

                <RadioGroup
                    android:id="@+id/radioGroup"
                    android:layout_width="match_parent"
                    android:layout_height="44dp"
                    android:background="@color/white"
                    android:gravity="center_vertical"
                    android:orientation="horizontal"
                    app:layout_scrollFlags="scroll">

                    

                    <RadioButton
                        android:id="@+id/replyCount"
                        android:layout_width="wrap_content"
                        android:layout_height="match_parent"
                        android:layout_marginLeft="10dp"
                        android:button="@null"
                        android:checked="true"
                        android:paddingLeft="12dp"
                        android:paddingRight="30dp"
                        android:text="@string/comment_count"
                        android:textColor="@color/selector_tweet_detail_tab"
                        android:textSize="14sp" />

                    <Space
                        android:layout_width="0dp"
                        android:layout_height="1dp"
                        android:layout_weight="1" />

                    <RadioButton
                        android:id="@+id/likeCount"
                        android:layout_width="wrap_content"
                        android:layout_height="match_parent"
                        android:button="@null"
                        android:paddingLeft="30dp"
                        android:paddingRight="15dp"
                        android:text="@string/like_count"
                        android:textColor="@color/selector_tweet_detail_tab"
                        android:textSize="14sp" />

                </RadioGroup>

            </LinearLayout>

        </android.support.design.widget.AppBarLayout>

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="vertical"
            app:layout_behavior="@string/appbar_scrolling_view_behavior">

            <View
                android:layout_width="match_parent"
                android:layout_height="2px"
                android:background="@color/colorLine" />

            <!-- viewpager可以有多個fragment，裏面可以用smartRefreshLayout -->
            <android.support.v4.view.ViewPager
                android:id="@+id/viewPager"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                app:layout_behavior="@string/appbar_scrolling_view_behavior" />

        </LinearLayout>

    </android.support.design.widget.CoordinatorLayout>

    

</RelativeLayout>

 

 

參考：https://www.jianshu.com/p/507091d4cc0f